Neurology_Adams

Neurology_Adams. The occurrence of paradoxical embolus is always a consideration in pregnancy because of a tendency to form clots in the pelvic and leg veins, coupled with increased right heart pressures. Amniotic fluid embolus may rarely cause stroke in this manner and should be suspected in multiparous women who have had uterine tears; there are almost invariably signs of acute pulmonary disease from simultaneous occlusion of lung vessels. A rare peripartum cardiomyopathy is yet another source of embolic stroke.


Neurology_Adams

Neurology_Adams. Incident to cardiac arrest and bypass surgery, there is risk of both generalized and focal ischemia of the brain. Improved operative techniques have lessened the frequency of these complications but they are still distressingly frequent. Fortunately, most are transient. Atherosclerotic plaques may be dislodged during cross-clamping of the proximal aorta and are an important source of cerebral emboli. In the last decade, the incidence of stroke related to cardiac surgery has dropped to between 2 and 3 percent in large series numbering thousands of patients (Libman et al; Ahlgren and Arén). Advanced age, congestive heart failure, and more complex surgeries have been listed as risk factors for stroke from various reports.


Neurology_Adams

Neurology_Adams. Representative is a retrospective study by Dashe and colleagues, in which 2 percent had strokes; most minor, but the risk was greatly increased on the side of a carotid stenosis. Curiously, almost one-fifth of postoperative strokes in some series have been of lacunar type. In one prospective study of 2,108 patients who underwent coronary operations in several institutions, 3 percent had strokes or TIAs; the adverse effects mostly occurred in older patients and were transient (Roach et al). Mohr and coworkers (1978) examined 100 consecutive cases preand postoperatively and observed two types of stroke-like complications—one occurring immediately after the operation and the other after an interval of days or weeks. The immediate neurologic disorder consisted of a delay in awakening from the anesthesia; subsequently there was slowness in thinking, disorientation, agitation, combativeness, visual hallucinations, and poor registration and recall of what was happening. These symptoms, in


Neurology_Adams

Neurology_Adams. anesthesia; subsequently there was slowness in thinking, disorientation, agitation, combativeness, visual hallucinations, and poor registration and recall of what was happening. These symptoms, in the form of a confusional state sometimes verging on delirium or acute psychosis, usually cleared within 5 to 7 days, although some patients were not entirely normal mentally weeks later. As the confusion cleared, about half of the patients were found to have small visual field defects, dyscalculia, Balint syndrome (see Chap. 21), alexia, or defects of perception suggestive of lesions in the parietooccipital regions. The immediate effects were attributed to hypotension and various types of embolisms (atherosclerotic, air, silicon, fat, platelets). The delayed effects were more clearly embolic and were especially frequent in patients having prosthetic valve replacements or other valve repairs.


Neurology_Adams

Neurology_Adams. In addition to overt and covert strokes detected only by imaging, a degree of cognitive decline and depression is to be expected in a proportion of patients undergoing coronary artery bypass grafting. The frequency of these changes is reported to be between 40 and 70 percent. It is our impression that many of these neurologic complications, both small strokes and cognitive abnormalities, pass unnoticed in many cardiac surgical units. This was emphasized in the study by McKhann and colleagues, who tested several neuropsychologic functions and found that only 12 percent of patients escaped some type of early cognitive problem. However, his group and others, for example, Mülges and colleagues, have shown that only a small proportion (13 percent in the latter series) retained permanent effects 5 years after operation. Others have reported higher rates, but it is clear that the cognitive problems improve over time in the majority of patients.


Neurology_Adams

Neurology_Adams. The use of Doppler insonation of the middle cerebral arteries is being studied to detect transient signals called HITs (high-intensity transients) as a manifestation of small emboli during surgery but, as for the transients frequently noted during cerebral arteriography, the clinical importance of these emboli is not known. In an attempt to avoid neurologic complication related to extracorporeal circulation, off-pump coronary artery bypass has been popularized in many centers. Unfortunately, most studies have found no fewer cognitive complications as compared to conventional coronary artery bypass surgery (e.g., see Shroyer et al). This is contrary to the notion that the extracorporeal apparatus is the cause of the problem. The issue of the neurologic complications of cardiac surgery may be summarized by noting that strokes originating from the aorta are the main cause of cognitive failure. The clinical syndromes seem to fall on a continuum; a few strokes (less than 3 percent) are


Neurology_Adams

Neurology_Adams. be summarized by noting that strokes originating from the aorta are the main cause of cognitive failure. The clinical syndromes seem to fall on a continuum; a few strokes (less than 3 percent) are recognizable as obvious deficits (e.g., hemiplegia), instead, many have multiple small emboli that are evident with imaging and these are manifest as an acute encephalopathy. When the burden of emboli is lower, no deficit is recognized in the acute period. It is likely that in patients with premorbid presymptomatic Alzheimer disease, confusion and dementia are made manifest by the stress of cardiac surgery and the surgery is then blamed for the emergence of an ostensibly new problem (see Samuels).


Neurology_Adams

Neurology_Adams. The other special stroke problems relating to prosthetic heart valves—mainly infective endocarditis causing embolic strokes and anticoagulant-related cerebral hemorrhage—are described in later sections of this chapter. This is the third most frequent cause of stroke, following cerebral embolism and thrombotic disease. Although more than a dozen causes of nontraumatic intracranial hemorrhage are listed in Table 33-8, hypertensive primary (“spontaneous”) intracerebral hemorrhage, ruptured saccular aneurysm and vascular malformation, and hemorrhage associated with the use of anticoagulants account for the majority. Cerebrovascular amyloidosis and acquired or congenital bleeding disorders account for a smaller number. The small brainstem hemorrhages secondary to temporal lobe herniation and brainstem compression (Duret hemorrhages), hypertensive encephalopathy, and brain purpura might be included in this group, but they do not simulate a stroke.


Neurology_Adams

Neurology_Adams. This is the often devastating “spontaneous” brain hemorrhage. It is still predominantly a result of chronic hypertension and degenerative changes in cerebral arteries. In recent decades, with increased awareness of the need to control blood pressure, the proportion of hemorrhages attributable to causes other than hypertension, mainly anticoagulation, has greatly increased so that more than half such hemorrhages on our services now occur in normotensive individuals, and the hemorrhages more often arise in locations that are not typical for hypertension. Nevertheless, the hypertensive cerebral hemorrhage serves as a model for understanding and managing other cerebral hemorrhages.


Neurology_Adams

Neurology_Adams. In approximate order of frequency, the most common sites of a cerebral hemorrhage are (1) the putamen and adjacent internal capsule (50 percent); (2) the central white matter of the temporal, parietal, or frontal lobes (lobar hemorrhages, not strictly associated with hypertension); (3) the thalamus; (4) one or the other cerebellar hemisphere; and (5) the pons. The vessel that ruptures, giving rise to the hemorrhage, is usually a small penetrating artery that originates from a larger trunk. Approximately 2 percent of primary hemorrhages are multiple. Multiple, nearly simultaneous intracerebral hemorrhages raise the possibility of amyloid angiopathy or a bleeding diathesis (see further on) but may occur when one conventional hypertensive intracerebral hemorrhage causes hypertension, which in turn leads to one or more additional hemorrhages.


Neurology_Adams

Neurology_Adams. The extravasation of blood into the substance of the brain forms a roughly circular or oval mass that disrupts the tissue and can grow in volume if the bleeding continues. Adjacent brain tissue is distorted and compressed. If the hemorrhage is large, midline structures are displaced to the opposite side of the cranium and the reticular activating and respiratory centers are compromised, leading to coma and death in the manner described in Chap. 16. It has been long known that both the size and the location of the clot determine the degree of secondary brainstem compression and this was confirmed by Andrew and associates. Rupture or seepage of blood into the ventricular system or rarely to the surface subarachnoid space may occur, and the CSF becomes bloody in these cases. In the first hours and days following the hemorrhage, varying degrees of edema evolve around the clot and add to the mass effect. Hydrocephalus may occur as a result of bleeding into the ventricular system or from


Neurology_Adams

Neurology_Adams. and days following the hemorrhage, varying degrees of edema evolve around the clot and add to the mass effect. Hydrocephalus may occur as a result of bleeding into the ventricular system or from compression of the third ventricle.


Neurology_Adams

Neurology_Adams. The extravasated blood undergoes a predictable series of changes. At first fluid, the collection becomes a clot within hours. Before the clot forms, red cells settle in the dependent part of the hematoma and form a meniscus with the plasma above; this is particularly prone to occur in cases of anticoagulant-induced hemorrhage. The resultant fluid–fluid level can be observed on CT and MRI (“hematocrit effect”). Hematomas, when examined in autopsy material, contain only masses of red blood cells and proteins; rarely one sees a few remnants of destroyed brain tissue. The hematoma is often surrounded by petechial hemorrhages from torn arterioles and venules. Within a few days, hemoglobin products, mainly hemosiderin and hematoidin, begin to appear. The hemosiderin forms within histiocytes that have phagocytized red blood cells (RBCs) and takes the form of ferritin granules that stain positively for iron. As oxyhemoglobin is liberated from the RBCs and becomes deoxygenated, methemoglobin


Neurology_Adams

Neurology_Adams. have phagocytized red blood cells (RBCs) and takes the form of ferritin granules that stain positively for iron. As oxyhemoglobin is liberated from the RBCs and becomes deoxygenated, methemoglobin appears. This begins within a few days and imparts a brownish hue to the periphery of the clot. Phagocytosis of red cells begins within 24 h, and hemosiderin is first observed around the margins of the clot in 5 to 6 days. The clot changes color gradually over a few weeks from dark red to pale red, and the border of golden-brown hemosiderin widens. The edema disappears over many days or weeks. In 2 to 3 months, larger clots are filled with a chrome-colored thick fluid, which is slowly absorbed, leaving a smooth-walled cavity or a yellow-brown scar. The iron pigment (hematin) becomes dispersed and studs adjacent astrocytes and neurons and may persist well beyond the border of the hemorrhage for years.


Neurology_Adams

Neurology_Adams. Imaging techniques demonstrate a predictable sequence of changes as shown in Fig. 33-24. On CT, fresh blood is visualized as a white mass as soon as it is shed. The “spot sign,” the appearance of contrast within the hemorrhage during CT angiography, is associated with a high rate of hematoma expansion. The mass effect and the surrounding extruded serum and edema are hypodense on CT. After 2 to 3 weeks, the surrounding edema begins to recede and the density of the hematoma decreases, first at the periphery. Gradually the clot becomes isodense with brain. There may be a ring of enhancement from the hemosiderin-filled macrophages and the reacting cells that form a capsule for the hemorrhage. At one point several weeks after the bleed, the appearance may transiently simulate a tumor or abscess. By MRI, either in conventional T1or T2-weighted images, the hemorrhage is not easily visible in the 2 or 3 days after bleeding, as oxyhemoglobin is diamagnetic or, at most, is slightly hypointense,


Neurology_Adams

Neurology_Adams. By MRI, either in conventional T1or T2-weighted images, the hemorrhage is not easily visible in the 2 or 3 days after bleeding, as oxyhemoglobin is diamagnetic or, at most, is slightly hypointense, so that only the mass effect is evident. MR gradient echo or equivalent sequences that display areas of magnetic susceptibility show hemorrhages earlier and detect remnants of deposited hemosiderin even years afterward.


Neurology_Adams

Neurology_Adams. After several days the surrounding edema is hyperintense in T2-weighted images. As deoxyhemoglobin and methemoglobin form, the hematoma signal becomes bright on T1-weighted images and dark on T2. The hematoma is then subacute and the dark signal gradually brightens. When methemoglobin disappears and only hemosiderin remains, the entire remaining mass is hypodense on T2-weighted images, as are the surrounding deposits of iron. The sizes of cerebral hemorrhages vary widely. Massive refers to hemorrhages several centimeters in diameter, usually larger than 50 mL; small applies to those 1 to 2 cm in diameter and less than 20 mL in volume. The volume and location relate to outcome and the nature of the initial neurologic deficit.


Neurology_Adams

Neurology_Adams. The hypertensive vascular lesion that leads to arteriolar rupture in most cases appears to arise from an arterial wall altered by the effects of hypertension, that is, the change referred to in a preceding section as segmental lipohyalinosis and the false aneurysm (microaneurysm) named for Charcot and Bouchard. Ross Russell’s work affirmed the relationship of these microaneurysms to hypertension and hypertensive hemorrhage and their frequent localization on penetrating small arteries and arterioles of the basal ganglia, thalamus, pons, and subcortical white matter. However, in the few hemorrhages examined in serial sections by C.M. Fisher (1959), the bleeding could not be traced to Charcot-Bouchard aneurysms. Takebayashi and coworkers, in an electron microscopic study, found breaks in the elastic lamina at multiple sites, almost always at bifurcations of the small vessels. Possibly these represented points of secondary rupture from tearing of small vessels by the expanding hematoma.


Neurology_Adams

Neurology_Adams. elastic lamina at multiple sites, almost always at bifurcations of the small vessels. Possibly these represented points of secondary rupture from tearing of small vessels by the expanding hematoma. Amyloid impregnation of vessel walls represents a different mechanism for vessel rupture, as discussed further on.


Neurology_Adams

Neurology_Adams. Of all the cerebrovascular diseases, brain hemorrhage is the most dramatic and from ancient times has been given its own name, “apoplexy.” The prototype was an obese, plethoric, hypertensive male who falls senseless to the ground—impervious to shouts, shaking, and pinching—breathes stertorously, and dies in a few hours. A massive blood clot escapes from the brain as it is removed postmortem. With smaller hemorrhages, the clinical picture conforms more closely to the usual temporal profile of a stroke, that is, an abrupt onset of symptoms that evolve gradually and steadily over minutes or hours, depending on the speed and expansion of bleeding.


Neurology_Adams

Neurology_Adams. In the majority of cases, the hemorrhage has its onset while the patient is up and active; onset during sleep is not common. There is no age predilection among adults except that the average age of occurrence is lower than in thrombotic infarction and neither sex is more disposed. The incidence of hypertensive cerebral hemorrhage is higher in African Americans than in whites and it occurs with higher frequency in people of Japanese descent.


Neurology_Adams

Neurology_Adams. Several general features of intracerebral hemorrhage should be emphasized. Acute reactive hypertension, far exceeding the patient’s chronic hypertensive level, is a feature that, in the context of a stroke, suggests hemorrhage; it is seen particularly with moderate and large clots situated in deep regions. Vomiting at the onset of intracerebral hemorrhage occurs much more frequently than with infarction and likewise suggests bleeding as the cause of an acute hemiparesis. Severe headache is generally considered to be an accompaniment of intracerebral hemorrhage and in many cases it is, but in almost half of cases it has been absent or mild. Nuchal rigidity is infrequent. If there is stiffness of the neck, it characteristically disappears as coma deepens. Or, the patient may be alert and responding accurately when first seen. Only if bleeding into the ventricles is massive or there is substantial distortion of the midbrain, does coma result.


Neurology_Adams

Neurology_Adams. Seizures, usually focal, occur in the first few days in only 10 percent of cases of supratentorial hemorrhage, rarely at the time of the ictus and more commonly as a delayed event, months or years after the hemorrhage. In the selected population of patients with cerebral hemorrhage who are continuously monitored by EEG in an intensive care unit, the frequency may be higher, up to one-third of which half are purely electrographic, according to Claassen and associates. This finding is interesting but does not seem to justify routine EEG monitoring.


Neurology_Adams

Neurology_Adams. The fundi often show hypertensive changes in the arterioles. Infrequently, fresh preretinal (subhyaloid) hemorrhages may occur but they are much more common with ruptured aneurysm, arteriovenous malformation, or severe cranial trauma. Therefore, headache, acute hypertension, and vomiting with hemiplegia in the case of bleeding into the cerebral hemisphere are the cardinal features and serve most dependably to distinguish hemorrhage from ischemic stroke on clinical grounds. In the localization of an intracerebral hemorrhage, ocular signs may be particularly useful. In putaminal hemorrhage, the eyes are deviated to the side opposite the paralysis; in thalamic hemorrhage, the most common ocular abnormality is downward deviation of the eyes and the pupils may be unreactive; in pontine hemorrhage, the eyeballs are fixed and the pupils are tiny but reactive; and in large cerebellar hemorrhage, the eyes may be deviated laterally to the side opposite the lesion and ocular bobbing may occur


Neurology_Adams

Neurology_Adams. the eyeballs are fixed and the pupils are tiny but reactive; and in large cerebellar hemorrhage, the eyes may be deviated laterally to the side opposite the lesion and ocular bobbing may occur (as often in cerebellar hemorrhage in awake patients there are no eye signs).


Neurology_Adams

Neurology_Adams. Small hemorrhages in some regions of the brain may escape clinical detection. Usually there are no warnings or prodromal symptoms; headache, dizziness, epistaxis, or other symptoms do not occur with any consistency.


Neurology_Adams

Neurology_Adams. There has long been a notion that acute hypertension can precipitate the hemorrhage. This is based on the anecdotal occurrence of cerebral hemorrhage at moments of extreme fright or anger or intense excitement, presumably as the blood pressure rises abruptly beyond its chronically elevated level. Similarly, hemorrhages have been described in relation to taking sympathomimetic medications such as phenylpropanolamine (Kernan et al), ephedra, or cocaine, and to numerous other hypertensive circumstances. However, in fully 90 percent of instances, the hemorrhage occurs when the patient is calm and unstressed, according to Caplan (1993). The level of blood pressure rises early in the course of the hemorrhage but the preceding chronic hypertension is usually of the “essential” type. Nonetheless, causes of hypertension must always be considered—renal disease, renal artery stenosis, eclampsia, pheochromocytoma, hyperaldosteronism, adrenocorticotropic hormone or corticosteroid excess and, of


Neurology_Adams

Neurology_Adams. causes of hypertension must always be considered—renal disease, renal artery stenosis, eclampsia, pheochromocytoma, hyperaldosteronism, adrenocorticotropic hormone or corticosteroid excess and, of course, sympathetically active drugs as mentioned.


Neurology_Adams

Neurology_Adams. It has been recognized by serial CT that in many instances, there is enlargement of the hematoma. In the series reported by Brott and colleagues (1997), 25 percent were found to have enlarged in the first hour and another 12 percent in the first day. Contrast extravasation into the adjacent brain after CTA was associated in a retrospective study with expansion of a hematoma, the aforementioned “spot sign” (Goldstein et al), but there are no other clear predictive factors of expansion of the clot. Blood in cerebral tissue is absorbed slowly over months during which time symptoms and signs recede. Hence the neurologic deficit is never transitory in intracerebral hemorrhage, as it so often is in TIA or embolism. The main types and locations of cerebral hemorrhage are described below and shown in Fig. 33-24. Chronic hypertension is associated with bleeding into the putamen, thalamus, pons, and cerebellum. Intracerebral bleeding at other sites, “lobar hemorrhages,” has numerous causes.


Neurology_Adams

Neurology_Adams. The most common syndrome is the one caused by putaminal hemorrhage with extension to the adjacent internal capsule (see Fig. 33-24A). Neurologic symptoms and signs vary slightly with the precise site and size of the extravasation, but hemiplegia from interruption of the capsule is a consistent feature of medium-sized and large clots. Vomiting occurs in about half the patients. Headache is frequent but not invariable. With large hemorrhages, patients lapse almost immediately into a stupor with hemiplegia and their condition visibly deteriorates as the hours pass. As often, there is headache or some other abnormal cephalic sensation. Within a few minutes or less the face sags on one side, speech becomes slurred or aphasic, the arm and leg weaken and are flaccid, and the eyes tend to deviate away from the side of the paretic limbs. These events, occurring gradually over a period of several minutes or more, are strongly suggestive of intracerebral bleeding. More advanced stages are


Neurology_Adams

Neurology_Adams. away from the side of the paretic limbs. These events, occurring gradually over a period of several minutes or more, are strongly suggestive of intracerebral bleeding. More advanced stages are characterized by signs of upper brainstem compression (coma); bilateral Babinski signs; irregular or intermittent respiration; dilated, fixed pupils, first on the side of the clot; and decerebrate rigidity.


Neurology_Adams

Neurology_Adams. Neuroimaging has disclosed the frequent occurrence of many smaller putaminal hemorrhages, which in former years would have been misdiagnosed as embolic or thrombotic strokes. With hemorrhages confined to the anterior segment of the putamen, the hemiplegia and hyperreflexia tend to be less severe and to clear more rapidly according to Caplan (1993). There is also prominent abulia, motor impersistence, temporary unilateral neglect, and with left-sided lesions, nonfluent aphasia, and dysgraphia. With small posterior lesions, weakness is also mild and is attended by sensory loss, hemianopia, impaired visual pursuit to the opposite side, Wernicke-type aphasia (left-sided lesions), and anosognosia (right-sided lesions).


Neurology_Adams

Neurology_Adams. The effects of relatively pure caudate hematoma have been difficult to define. Those extending laterally and posteriorly into the internal capsule behave much like large putaminal hemorrhages. Those extending medially into the lateral ventricle give rise to drowsiness, stupor, and either confusion and underactivity or restlessness and agitation. The central feature here is severe sensory loss on the entire contralateral body. If large or moderate in size, thalamic hemorrhage also produces a hemiplegia or hemiparesis by compression or destruction of the adjacent internal capsule (see Fig. 33-24B). The sensory deficit involves all of the opposite side including the trunk and may exceed the motor weakness. A fluent aphasia or anemia may be present with lesions of the dominant side and contralateral neglect, with lesions of the nondominant side. A homonymous field defect, if present, usually clears in a few days.


Neurology_Adams

Neurology_Adams. Thalamic hemorrhage, by virtue of its extension into the subthalamus and high midbrain, may also cause a series of ocular disturbances—pseudoabducens palsies with one or both eyes turned asymmetrically inward and slightly downward, palsies of vertical and lateral gaze, forced deviation of the eyes downward, inequality of pupils with absence of light reaction, skew deviation with the eye ipsilateral to the hemorrhage assuming a higher position than the contralateral eye, ipsilateral ptosis and miosis (Horner syndrome), absence of convergence, retraction nystagmus, and tucking in (retraction) of the upper eyelids. Extension of the neck may be observed. Compression of the adjacent third ventricle leads to enlargement of the lateral ventricles that may require temporary drainage. Small and moderate-sized hemorrhages that rupture into the third ventricle have been associated with fewer neurologic deficits and better outcomes, but early hydrocephalus is common.


Neurology_Adams

Neurology_Adams. Hemorrhage into the pons is almost invariably associated with deep coma within a few minutes; the remainder of the clinical picture is dominated by total paralysis with bilateral Babinski signs, decerebrate rigidity, and small (1 mm) pupils that react to light. Lateral eye movements, evoked by head turning or caloric testing, are impaired or absent. Death usually occurs within a few hours, but there are exceptions in which consciousness is retained and the clinical manifestations indicate a smaller lesion in the tegmentum of the pons (disturbances of lateral ocular movements, crossed sensory or motor disturbances, small pupils, and cranial-nerve palsies) in addition to signs of bilateral corticospinal tract involvement. A number of our patients with limited tegmental hemorrhages and blood in the CSF have survived with good functional recovery. In a series of 60 patients with pontine hemorrhage reviewed by Nakajima, 19 survived (8 of whom had remained alert). Similarly, Wijdicks and


Neurology_Adams

Neurology_Adams. in the CSF have survived with good functional recovery. In a series of 60 patients with pontine hemorrhage reviewed by Nakajima, 19 survived (8 of whom had remained alert). Similarly, Wijdicks and St. Louis reported that 21 percent made a good recovery—mostly those who were awake on admission. Figure 33-24C depicts a typical pontine hemorrhage.


Neurology_Adams

Neurology_Adams. This usually develops over a period of 1 or more hours, and loss of consciousness at the onset is unusual. Repeated vomiting is a prominent feature, with occipital headache, vertigo, and inability to sit, stand, or walk. Often these are the only abnormalities, making it imperative to have the patient attempt to ambulate; otherwise the examination may erroneously seem to be normal. In the early phase of the illness other clinical signs of cerebellar disease are usually minimal or lacking; only a minority of cases shows nystagmus or cerebellar ataxia of the limbs, although these signs must always be sought. A mild ipsilateral facial weakness, diminished corneal reflex, paresis of conjugate lateral gaze to the side of the hemorrhage, or an ipsilateral sixth-nerve weakness occur with larger hemorrhages that compress the pons or extend into the cerebellar peduncle. Dysarthria and dysphagia may be prominent in some cases but usually are absent. Other infrequent ocular signs include


Neurology_Adams

Neurology_Adams. larger hemorrhages that compress the pons or extend into the cerebellar peduncle. Dysarthria and dysphagia may be prominent in some cases but usually are absent. Other infrequent ocular signs include blepharospasm, involuntary closure of one eye, skew deviation, “ocular bobbing,” and small, often unequal pupils that continue to react until very late in the illness. Contralateral hemiplegia and ipsilateral facial weakness occur if there is marked displacement and compression of the medulla against the clivus.


Neurology_Adams

Neurology_Adams. Occasionally at the onset there is a spastic paraparesis or a quadriparesis with preservation of consciousness. The plantar reflexes are flexor in the early stages but extensor later. When these signs occur, hydrocephalus is usually found and may require drainage. In the series collected by St. Louis and colleagues, patients with vermian clots and hydrocephalus were at the highest risk for rapid deterioration. As the hours pass, and occasionally with unanticipated suddenness, the patient becomes stuporous and then comatose or suddenly apneic as a result of brainstem compression, at which point reversal of the syndrome, even by surgical therapy, is seldom successful. As discussed further on, cerebellar hemorrhage is the most amenable to surgical evacuation with good results. A typical case is shown with imaging in Fig. 33-24D.


Neurology_Adams

Neurology_Adams. Bleeding in areas other than those listed above, specifically in the subcortical white matter of one of the lobes of the cerebral hemisphere, is not associated strictly with hypertension. Any number of other causes are usually responsible, the main ones being anticoagulation or thrombolytic therapy, acquired coagulopathies, cranial trauma, arteriovenous malformation (discussed further on), trauma, and, in the elderly, amyloidosis of the cerebral vessels. The role of antiplatelet agents in precipitating intracerebral hemorrhage has been a matter of contention with numerous surveys and studies giving divergent results regarding larger, expanding or more clinically destructive hematomas. Most lobar hemorrhages are spherical or ovoid, but a few follow the contour of the subcortical white matter tracts and take the form of a slit (subcortical slit hemorrhage). It is our impression that many of these are the result of a bleeding diathesis, such as thrombocytopenia.


Neurology_Adams

Neurology_Adams. In a consecutive series of 26 cases of lobar hemorrhage, we found 11 to lie within the occipital lobe, causing pain around the ipsilateral eye and a dense homonymous hemianopia; 7 in the temporal lobe that produced pain in or anterior to the ear, partial hemianopia, and fluent aphasia; 4 in the frontal lobe, with frontal headache and contralateral hemiplegia, mainly of the arm; and 3 in the parietal lobe that presented with anterior temporal headache and hemisensory deficit contralaterally (Ropper and Davis). The smaller hematomas simulate an embolic stroke in the same territory. The occurrence of a progressively worsening headache, vomiting, or drowsiness in conjunction with any one of these syndromes is virtually diagnostic, and, of course, the presence of a lobar hemorrhage is readily corroborated by an unenhanced CT. Of our 26 patients, 14 had normal blood pressure, and in several of the fatal cases there was amyloidosis of the affected vessels; 2 patients were receiving


Neurology_Adams

Neurology_Adams. readily corroborated by an unenhanced CT. Of our 26 patients, 14 had normal blood pressure, and in several of the fatal cases there was amyloidosis of the affected vessels; 2 patients were receiving anticoagulants, 2 had an arteriovenous malformation, and 1 had a metastatic tumor. Similarly, in the series of 22 patients with lobar clots reported by Kase and colleagues, 55 percent were normotensive; metastatic tumors, arteriovenous malformations, and blood dyscrasias were found in 14, 9, and 5 percent of the patients, respectively. The role of amyloid angiopathy in lobar hemorrhage in the elderly patient is discussed further on.


Neurology_Adams

Neurology_Adams. For the rapid diagnosis of intracerebral hemorrhage, cerebral imaging occupies the foremost position (see Fig. 33-24). It is reliable in the detection of hemorrhages that are less than 1.0 cm in diameter. Very small pontine hemorrhages may be overlooked because of the artifact produced by adjacent bone. The spot sign on CT angiography has been mentioned above in relation to hematoma expansion. At the same time, coexisting hydrocephalus, tumor, cerebral swelling, and displacement of the intracranial contents are readily appreciated. MRI is particularly useful for demonstrating brainstem hemorrhages and residual hemorrhages, which remain visible long after they are no longer detectable on the CT (after 4 to 5 weeks). Hemosiderin and iron pigment have characteristic appearances, as described earlier and in Chap. 2.


Neurology_Adams

Neurology_Adams. In general, lumbar puncture is ill advised, for it may precipitate or aggravate an impending shift of central structures and herniation. The white cell count in the peripheral blood may rise transiently to 15,000/mm3, a higher figure than in thrombosis, but it is most often normal. The sedimentation rate may be mildly elevated in some patients. Determination of the INR, partial thromboplastin time, and platelet count is advisable.


Neurology_Adams

Neurology_Adams. The immediate prognosis for large and medium-sized cerebral clots is grave; some 30 to 35 percent of patients die in 1 to 30 days. In these cases, either the hemorrhage has extended into the ventricular system or intracranial pressure becomes elevated to levels that preclude normal perfusion of the brain. Or the hemorrhage seeps into vital centers such as the hypothalamus or midbrain. A formula that predicts outcome of hemorrhage based on clot size was devised by Broderick and coworkers (1993); it is mainly applicable to putaminal and thalamic clots. A volume of 30 mL or less, calculated by various methods from the CT predicted a generally favorable outcome; only 1 of their 71 patients with clots larger than 30 mL had regained independent function by 1 month. By contrast, in patients with clots of 60 mL or larger and an initial Glasgow Coma Scale score of 8 or less, the mortality was 90 percent (this scale is detailed in Table 35-1). As remarked earlier, it is the location of the


Neurology_Adams

Neurology_Adams. with clots of 60 mL or larger and an initial Glasgow Coma Scale score of 8 or less, the mortality was 90 percent (this scale is detailed in Table 35-1). As remarked earlier, it is the location of the hematoma, not simply its size that determines the clinical effects. A clot 60 mL in volume is almost uniformly fatal if situated in the basal ganglia but may allow reasonably good outcome if located in the frontal or occipital lobe. From the studies of Diringer and colleagues (1998), hydrocephalus is also an important predictor of poor outcome, and this accords with our experience. Prompt drainage of the ventricles can markedly improve the clinical state.


Neurology_Adams

Neurology_Adams. Several other scoring systems that are intended to predict prognosis have been devised and validated. The two in main use, shown in Table 33-9, are “FUNC” produced by Rost and coworkers, which incorporates the patient’s age, size and location of hematoma, the presence of preexisting cognitive impairment, and Glasgow Coma score (see Chap. 16); and the “ICH score” devised by Hemphill and colleagues that uses GCS, volume, presence of intraventricular hemorrhage, the location—supraor infratentorial, and age above or below 80 years. The value of these scores may be in advising families regarding the appropriate intensity of medical care but it must be realized that these point estimates of outcomes based on numerical scores have wide confidence intervals. Indeed, of all the cerebrovascular diseases, cerebral hemorrhage may give the most discouraging clinical picture initially and yet have a reasonable clinical outcome and such scores must be tempered by clinical experience.


Neurology_Adams

Neurology_Adams. In patients who survive, there can be a surprising degree of restoration of function, because, in contrast to infarction, the hemorrhage has to some extent pushed brain tissue aside rather than destroyed it. Function returns very slowly, however, because extravasated blood takes time to be removed from the tissues. Healed scars impinging on the cortex are liable to be epileptogenic; the frequency of seizures after each type of hemorrhage has not been established, but it is lower than for ischemic strokes. There is no need to administer anticonvulsive medication unless a seizure has occurred. The poor prognosis of all but the smallest pontine hemorrhages has already been mentioned. Cerebellar hemorrhages present special problems that are discussed below. Treatment of Cerebral Hemorrhage


Neurology_Adams

Neurology_Adams. Treatment of Cerebral Hemorrhage The management of patients with large intracerebral hemorrhages and coma includes the maintenance of adequate ventilation, selective acute use of controlled hyperventilation to a Pco2 of 25 to 30 mm Hg, monitoring of intracranial pressure in some cases and its control by the use of tissue-dehydrating agents such as mannitol (osmolality kept at 295 to 305 mOsm/L and Na at 145 to 150 mEq), and limiting intravenous infusions to normal saline. Qureshi’s group offered data suggesting that aggressive measures to reduce intracranial pressure may be lifesaving and result in good outcome even in patients who have signs of transtentorial herniation. In our experience, this type of recovery is exceptional, but medical treatment of raised intracranial pressure may be justified in patients whose medical condition allows it.


Neurology_Adams

Neurology_Adams. As mentioned, most patients with intracerebral hemorrhage are hypertensive immediately after the stroke because of a generalized sympathoadrenal response. The natural trend is for the blood pressure to diminish over several days; therefore active treatment in the acute stages has been a matter of controversy. Rapid reduction of moderately elevated blood pressure (between 140 and 160 mm Hg systolic), in the hope of reducing further bleeding, is not recommended, because it risks compromising cerebral perfusion in cases of raised intracranial pressure. On the other hand, sustained mean blood pressures of greater than 110 mm Hg (generally above 160 mm Hg systolic) may exaggerate cerebral edema and perhaps enhance the risk extension of the clot. It is at approximately this level of acute hypertension that the use of beta-blocking drugs (esmolol, labetalol) or angiotensin-converting enzyme (ACE) inhibitors is recommended. The major calcium channel-blocking drugs are used less often for this


Neurology_Adams

Neurology_Adams. that the use of beta-blocking drugs (esmolol, labetalol) or angiotensin-converting enzyme (ACE) inhibitors is recommended. The major calcium channel-blocking drugs are used less often for this purpose because of reports of adverse effects on intracranial pressure, although this information derives mainly from patients with brain tumors. Hayashi and associates have shown that although blood pressure is lowered with nifedipine after cerebral hemorrhage, intracranial pressure is raised, resulting in an unfavorable net reduction in cerebral perfusion pressure.


Neurology_Adams

Neurology_Adams. In a randomized trial of rapid reduction in blood pressure in patients with acute cerebral hemorrhage, Anderson and colleagues (2013) found that targeting a level of systolic blood pressure below 140 mm Hg within an hour resulted in similar overall clinical outcomes and mortality to guideline-recommended treatment that targets a systolic blood pressure of less than 180 mm Hg. More rapidly acting and titratable agents such as nitroprusside may be used in extreme situations, recognizing that they may further raise intracranial pressure.


Neurology_Adams

Neurology_Adams. Although it would appear intuitively that evacuation of a hematoma might be beneficial, surgical results have not been found to be superior to medical measures alone (Waga and Yamamoto; Batjer et al; Juvela et al; Rabinstein et al). A multicenter, randomized study involving 1,033 patients with supratentorial hemorrhage, under the auspices of the Surgical Trial in Intracerebral Haemorrhage (STICH) study reported by Mendelow and colleagues, has failed to show a benefit from early surgery on survival or neurologic functioning at 6 months. This negative result extended to almost all levels of neurologic deficit and all age groups. In a post hoc analysis, clots that were small and close to the surface of the brain may have benefited from evacuation. As a result, a direct surgical approach has been used less frequently than in the past, but we acknowledge that in a few instances with ongoing deterioration in young patients with hematomas that were easily accessible from the cortical


Neurology_Adams

Neurology_Adams. has been used less frequently than in the past, but we acknowledge that in a few instances with ongoing deterioration in young patients with hematomas that were easily accessible from the cortical surface, we have asked our neurosurgical colleagues to undertake evacuation of the clot.


Neurology_Adams

Neurology_Adams. Several alternatives are available when cerebral hemorrhage is the result of an anticoagulant. In addition to vitamin K, which may not act immediately, warfarin related hemorrhages can be treated with fresh frozen plasma, although 6 to 8 units may be required and this is a large volume to handle for elderly patients or those with congestive heart failure. Protein complex concentrates containing varying amounts of vitamin K dependent factors (II, VII, IX, X) and particularly VII have been used but their superiority over other approaches has been difficult to demonstrate. Orally administered factor Xa inhibitors and direct thrombin inhibitors now have specific antidotes. Cerebral hemorrhage associated with severe thrombocytopenia is generally treated with platelet infusions but the results are variable since the underlying disease that caused thrombocytopenia is often the determining factor. There has been controversy regarding the administration of platelets to patients who were on


Neurology_Adams

Neurology_Adams. are variable since the underlying disease that caused thrombocytopenia is often the determining factor. There has been controversy regarding the administration of platelets to patients who were on antiplatelet therapy; we often will administer several units if a patient has been on dual antiplatelet therapy and particularly, there is evidence of expansion of the hematoma. Tissue plasminogen activator related cerebral hemorrhage is generally treated with fibrinogen concentrate. Mayer and coworkers studied the promising approach of administering clotting factor VII within 4 h of spontaneous cerebral hemorrhage. In a preliminary study, survival was improved and there was a reduction in enlargement of the hematoma, but a subsequent trial failed to confirm the benefit on survival.


Neurology_Adams

Neurology_Adams. If acute hydrocephalus has resulted from a centrally placed hemorrhage or rupture into the ventricular system, a extraventricular drain may be needed. These blood-filled drains frequently become clotted and in a study of the infused tissue plasminogen activator through the ventricular catheter no difference was found in overall functional outcome (Hanley et al) but often, there are limited alternatives besides this to keep the apparatus open to drain bloody cerebrospinal fluid. It has been appreciated for some time that intraventricular extension of cerebral hemorrhage generally denotes a poor outcome. An exception may be small thalamic hemorrhages.


Neurology_Adams

Neurology_Adams. Once the patient with a supratentorial hemorrhage becomes deeply comatose with dilated fixed pupils, the chance of recovery is negligible. Even in retrospective studies in which clinical worsening was the reason for surgery, such as the one by Rabinstein and colleagues, only 25 percent of patients attained a state of functional independence and all of their patients who lost their brainstem reflexes and had extensor posturing died despite surgery; there have been a few exceptions to this observation. Some of the mortality in series of cerebral hemorrhage patients is undoubtedly due to the self-fulfilling aspect of withdrawal of care in seemingly hopeless circumstances.


Neurology_Adams

Neurology_Adams. In comatose patients with large hemorrhages, the placement of a device for monitoring of intracranial pressure enables the clinician to use medical measures with greater precision, as outlined in Chap. 16, but there is no evidence that outcome is significantly improved (Ropper and King). Whether hemicraniectomy is of value, as it is with large hemispheral strokes, is not known but it seems unlikely. Cerebellar hemorrhage represents a special case regarding neurosurgery, as commented below.


Neurology_Adams

Neurology_Adams. The issue often arises of the appropriate timing of restarting anticoagulation in patients whose hemorrhage occurred on warfarin. In some instances, such as a prosthetic heart valve requires warfarin, medication is often reintroduced after a week or two. However, for the more common indication of this drug, namely atrial fibrillation, there have been diverging suggestions from different surveys. In an often-cited study by Majeed and colleagues, a retrospective review of almost 3,000 patients over 6 years suggested that the risk of creating another hemorrhage by restarting warfarin earlier than 10 to 30 weeks after the initial stroke was quite high.


Neurology_Adams

Neurology_Adams. Surgical evacuation of cerebellar hematoma The surgical evacuation of cerebellar hematoma is a generally accepted treatment and is an urgent matter because of the proximity of the mass to the brainstem and the risk of abrupt respiratory failure. Also, hydrocephalus from compression of the fourth ventricle often complicates the clinical picture and further raises intracranial pressure (St. Louis et al). As a rule, a cerebellar hematomas less than 2 cm in diameter leaves most patients awake and infrequently leads to deterioration, therefore generally not requiring surgery. Hematomas that are 4 cm or more in largest diameter, especially if located in the vermis, pose the greatest risk, and some surgeons have recommended evacuation of lesions of this size no matter what the clinical status of the patient. In determining the need for surgical evacuation, we have been guided by the patient’s state of consciousness, the mass effect caused by the clot as visualized on imaging (particularly


Neurology_Adams

Neurology_Adams. of the patient. In determining the need for surgical evacuation, we have been guided by the patient’s state of consciousness, the mass effect caused by the clot as visualized on imaging (particularly the degree of compression of the quadrigeminal cistern, as pointed out by Taneda and colleagues), and the presence or absence of hydrocephalus. Assessment may require daily or even more frequent CT. The patient who is stuporous or displays arrhythmic breathing is best intubated and brought to the operating room within hours or sooner. Once coma and pupillary changes supervene, few patients survive, even with surgery; however, rapid medical intervention with mannitol and hyperventilation, followed by surgical evacuation of the clot and drainage of the ventricles within hours of the onset of coma has been successful in some cases. Patients who are drowsy and those with hematomas of 2 to 4 cm in diameter in the cerebellar hemisphere pose the greatest difficulty in determining if, and when,


Neurology_Adams

Neurology_Adams. has been successful in some cases. Patients who are drowsy and those with hematomas of 2 to 4 cm in diameter in the cerebellar hemisphere pose the greatest difficulty in determining if, and when, surgery is advisable. If the level of consciousness is fluctuating or if there is obliteration of the perimesencephalic cisterns, particularly if coupled with hydrocephalus, the risk of surgery may be lower than the risk of a sudden deterioration. In only a very limited number of patients have we found it practical to perform only drainage of the enlarged ventricles, although some groups still favor this procedure and eschew a posterior fossa operation. Evacuation of the clot in our experience has been more important than reduction of the hydrocephalus.


Neurology_Adams

Neurology_Adams. This is the fourth most frequent cerebrovascular disorder—following embolism, atherothrombosis including lacunes, and primary intracerebral hemorrhage, but one that is often disastrous. Saccular aneurysms are also called “berry” aneurysms because they take the form of small, thin-walled blisters protruding from arteries of the circle of Willis or its major branches. Their rupture causes a flooding of the subarachnoid space with blood under high pressure. As a rule, the aneurysms are located at vessel bifurcations and branchings (Fig. 33-25) and are generally presumed to result from developmental defects in the media and elastica of the arteries. An alternate theory holds that the aneurysmal process is initiated by focal destruction of the internal elastic membrane, which is produced by hemodynamic forces at the apices of bifurcations (Ferguson). As a result of the local weakness in the vessel wall, the intima bulges outward, covered only by adventitia; the sac then gradually enlarges


Neurology_Adams

Neurology_Adams. forces at the apices of bifurcations (Ferguson). As a result of the local weakness in the vessel wall, the intima bulges outward, covered only by adventitia; the sac then gradually enlarges and may finally rupture. Cerebral aneurysms vary in size from 2 mm to 2 or 3 cm in diameter, averaging 7.5 mm (Wiebers et al, 1981 and 1987). Those that rupture usually have a diameter of 10 mm or more, but rupture also occurs, albeit less often, in those of smaller size. Aneurysms vary greatly in form. Some are round and connected to the parent artery by a narrow stalk; others are broad-based without a stalk; and still others take the form of narrow cylinders. The site of rupture is usually at the dome of the aneurysm, which may have one or more secondary sacculations. A review of the subject by Schievink gives further details of this extensively studied subject.


Neurology_Adams

Neurology_Adams. The incidence of unruptured aneurysms in routine autopsies is almost 2 percent—excluding minor vessel outpouchings of 3 mm or less. Moreover, aneurysms are multiple in 20 percent of patients. In the past, it was estimated that 400,000 Americans harbored unruptured aneurysms and that there were 26,000 aneurysmal subarachnoid hemorrhages per year (Sahs et al, 1981 and 1984). Rupture of saccular aneurysms in childhood is rare, and they are seldom found at routine postmortem examination in this age group; beyond childhood, they gradually increase in frequency to reach their peak incidence between ages 35 and 65 years. Therefore aneurysms cannot be regarded as typical congenital anomalies; rather, they appear to develop over the years on the basis of either a developmental or acquired arterial defect. There is an increased incidence of polycystic kidneys, fibromuscular dysplasia of the extracranial arteries, moyamoya, arteriovenous malformations of the brain, and coarctation of the aorta


Neurology_Adams

Neurology_Adams. defect. There is an increased incidence of polycystic kidneys, fibromuscular dysplasia of the extracranial arteries, moyamoya, arteriovenous malformations of the brain, and coarctation of the aorta among persons with saccular aneurysms and vice versa. An accompanying saccular aneurysm is found in approximately 5 percent of cases of cerebral arteriovenous malformation, usually on the main feeding artery of the malformation.


Neurology_Adams

Neurology_Adams. Numerous reports have documented a familial occurrence of saccular aneurysms, lending support to the idea that genetic factors play a role in their development. Numerous genetic associations have been reported, none entirely convincing. The number of first-degree relatives found to harbor an unsuspected aneurysm has been approximately 4 percent in most series. This low rate, the finding that half of the discovered aneurysms are small, and the complications of surgery make routine screening of siblings, children, and parents of patients with ruptured aneurysms impractical, according to the Magnetic Resonance Angiography in Relatives of Patients with Subarachnoid Hemorrhage Study Group. However, because aneurysms of the familial variety tend to be larger at the time of rupture and more numerous than in patients who have sporadic ones, there are exceptions to this statement (Ruigrok et al), and there is little question that, in practice, the close relatives of patients with ruptured


Neurology_Adams

Neurology_Adams. numerous than in patients who have sporadic ones, there are exceptions to this statement (Ruigrok et al), and there is little question that, in practice, the close relatives of patients with ruptured aneurysms ask for, and are accommodated, screening for aneurysms. From a survey in Scotland, the lifetime risk of hemorrhage was only 4.7 percent for a first-degree relative and 1.9 percent for a second-degree relative (Teasdale et al). From several series, it is apparent that the risk is highest for individuals with two or more first-degree relatives and negligible for one second-degree relative.


Neurology_Adams

Neurology_Adams. Although hypertension is more frequently present than in the general population, aneurysms most often occur in persons with normal blood pressure. Pregnancy does not appear to be associated with an increased incidence of aneurysmal rupture, although there is always theoretical concern about the possibility of inducing bleeding during the straining of natural delivery. Atherosclerosis, although present in the walls of some saccular aneurysms, probably plays no part in their formation or enlargement. Approximately 90 to 95 percent of saccular aneurysms lie on the anterior part of the circle of Willis (see


Neurology_Adams

Neurology_Adams. Approximately 90 to 95 percent of saccular aneurysms lie on the anterior part of the circle of Willis (see Fig. 33-25). The four most common sites are (1) the proximal portions of the anterior communicating artery, (2) at the origin of the posterior communicating artery from the stem of the internal carotid, (3) at the first major bifurcation of the middle cerebral artery, and (4) at the bifurcation of the internal carotid into middle and anterior cerebral arteries. Other sites include the internal carotid artery in the cavernous sinus, at the origin of the ophthalmic artery, the junction of the posterior communicating and posterior cerebral arteries, the bifurcation of the basilar artery, and the origins of the cerebellar arteries. Aneurysms of the carotid artery that rupture in the cavernous sinus give rise to an arteriovenous fistula (see further on).


Neurology_Adams

Neurology_Adams. There are several types of aneurysms other than saccular, for example, mycotic, fusiform, diffuse, and globular. The mycotic aneurysm is caused by a septic embolus that weakens the wall of the vessel in which it lodges, almost always at a site in a distal cerebral vessel, well beyond the circle of Willis. These lesions are discussed separately in a later section of this chapter. The others are named for their predominant morphologic characteristics and consist of enlargement or dilatation of the entire circumference of the involved vessels, usually the internal carotid, vertebral, or basilar arteries. Fusiform deformities are also referred to as arteriosclerotic aneurysms, as they frequently show atheromatous deposition in their walls, but it is likely that they are at least partly developmental in nature. Some are very large (so-called giant aneurysms) and press on neighboring structures or become occluded by thrombus, but they rupture only infrequently (as discussed further on).


Neurology_Adams

Neurology_Adams. With rupture of the aneurysm, blood under high pressure is forced into the subarachnoid space and the resulting clinical events assume one of three patterns: (1) the patient is stricken with an excruciating generalized headache and vomiting and falls unconscious almost immediately; (2) severe generalized headache develops in the same instantaneous manner but the patient remains relatively lucid with varying degrees of stiff neck—the most common syndrome; (3) rarely, consciousness is lost so quickly that there is no preceding complaint. If the hemorrhage is massive, death may ensue in a matter of minutes or hours, so that ruptured aneurysm must be considered in the differential diagnosis of sudden death. A considerable proportion of such patients probably never reach a hospital. Decerebrate rigidity and brief clonic jerking of the limbs may occur at the onset of the hemorrhage, always in association with unconsciousness. Persistent deep coma is accompanied by irregular respirations,


Neurology_Adams

Neurology_Adams. rigidity and brief clonic jerking of the limbs may occur at the onset of the hemorrhage, always in association with unconsciousness. Persistent deep coma is accompanied by irregular respirations, attacks of extensor rigidity, and finally respiratory arrest and circulatory collapse. In these rapidly evolving cases, the subarachnoid blood has greatly increased the intracranial pressure to a level that approaches arterial pressure and caused a marked reduction in cerebral perfusion. In some instances, the hemorrhage has dissected intracerebrally and entered the brain or ventricular system.


Neurology_Adams

Neurology_Adams. Rupture of the aneurysm usually occurs while the patient is active rather than during sleep, and in a few instances, during sexual intercourse, straining at stool, lifting heavy objects, or other sustained exertion (see “Headaches Related to Sexual Activity” in Chap. 9). A momentary Valsalva maneuver, as in coughing or sneezing, has generally not caused aneurysmal rupture (it may cause arterial dissection). In patients who survive the initial rupture, the most feared complication is rerupture, an event that may occur at any time from minutes up to 2 or 3 weeks.


Neurology_Adams

Neurology_Adams. In less-severe cases, consciousness, if lost, is regained within minutes or hours, but a residuum of drowsiness, confusion, and amnesia accompanied by severe headache and stiff neck persists for at least several days. Because the hemorrhage in most cases is confined to the subarachnoid space, there are few if any focal neurologic signs. That is to say, hemiparesis, hemianopia, and aphasia are absent. On occasion, a jet of blood emanating from an aneurysm ruptures into the adjacent brain or insular cistern and produces a hemiparesis or other focal syndrome. This may be more common when the aneurysm has bled in the past, after which it adheres to the brain, thus predisposing to intracerebral hemorrhage at the time of subsequent rupture. There is, however, a transient focal acute syndrome that occasionally occurs in the territory of the aneurysm-bearing artery. The pathogenesis of such manifestations is not fully understood, but a transitory fall in pressure in the circulation distal to


Neurology_Adams

Neurology_Adams. occasionally occurs in the territory of the aneurysm-bearing artery. The pathogenesis of such manifestations is not fully understood, but a transitory fall in pressure in the circulation distal to the aneurysm or some form of acute transient vasospasm has been postulated. An entirely separate problem of delayed vasospasm is responsible for focal signs that emerge after several days as discussed below. Transient deficits when they do occur constitute reliable indicators of the site of the ruptured aneurysm (see below).


Neurology_Adams

Neurology_Adams. Convulsive seizures, usually brief and generalized, occur in 10 to 25 percent of cases according to Hart and associates (1981) (but far less often in our experience) in relation to acute bleeding or rebleeding. These early seizures do not correlate with the location of the aneurysm and do not appear to alter the prognosis.


Neurology_Adams

Neurology_Adams. Prior to rupture, saccular aneurysms are usually asymptomatic. Exceptionally, if large enough to compress pain-sensitive structures, they may cause localized cranial pain. With a cavernous or anterolaterally situated aneurysm on the first part of the middle cerebral artery, the pain may be projected to the orbit. An aneurysm on the posteroinferior or anteroinferior cerebellar artery may cause unilateral occipital or cervical pain. The presence of a partial oculomotor palsy with dilated pupil may be indicative of an aneurysm of the posterior communicating–internal carotid junction or at the posterior communicating– posterior cerebral junction. Occasionally, large aneurysms just anterior to the cavernous sinus compress the optic nerves or chiasm, third nerve, hypothalamus, or pituitary gland. A monocular visual field defect may also develop with a supraclinoid aneurysm near the anterior and middle cerebral bifurcation or the ophthalmic–carotid bifurcation. In the cavernous sinus, they


Neurology_Adams

Neurology_Adams. A monocular visual field defect may also develop with a supraclinoid aneurysm near the anterior and middle cerebral bifurcation or the ophthalmic–carotid bifurcation. In the cavernous sinus, they may compress the third, fourth, or sixth nerve, or the ophthalmic division of the fifth nerve.


Neurology_Adams

Neurology_Adams. Whether a small leak of blood from an aneurysm may serve as a warning sign of a subsequent more catastrophic rupture (“warning leak”) has been disputed. An entity known as “sentinel headache” has been used in an imprecise way to refer to both a headache that precedes subarachnoid hemorrhage and to a small leakage prior to a major rupture. Headaches are so ubiquitous that many, even severe ones, are coincidental in relation to subarachnoid hemorrhage. The frequency of true warming leaks is unknown but is not likely to be high. We have seen several cases where an acute and severe exertional or spontaneous headache was found to be associated with a small subarachnoid hemorrhage that was discovered by lumbar puncture; more often the headache is unrelated to hemorrhage and is attributable to migraine. This type of “thunderclap headache,” may be a variant of migraine, or less often, cerebral venous thrombosis, diffuse vasospasm (reversible cerebral vasoconstriction syndrome [RCVS], formerly


Neurology_Adams

Neurology_Adams. This type of “thunderclap headache,” may be a variant of migraine, or less often, cerebral venous thrombosis, diffuse vasospasm (reversible cerebral vasoconstriction syndrome [RCVS], formerly called Call-Fleming syndrome), or even less often, pituitary apoplexy, hypertensive encephalopathy, intracranial hypotension, and intracranial or extracranial arterial dissection.


Neurology_Adams

Neurology_Adams. Before deciding on a course of action, it has been useful to assess the patient with reference to the widely employed scale introduced by Botterell and colleagues and refined by Hunt and Hess, as follows: Grade I. Asymptomatic or with slight headache and stiff neck Grade II. Moderate to severe headache and nuchal rigidity but no focal or lateralizing neurologic signs Grade III. Drowsiness, confusion, and mild focal deficit Grade IV. Persistent stupor or semicoma, early decerebrate rigidity and vegetative disturbances Grade V. Deep coma and decerebrate rigidity


Neurology_Adams

Neurology_Adams. Imaging has taken a more prominent role in the diagnosis of subarachnoid hemorrhage than in the past when lumbar puncture, still very useful, predominated. CT will detect blood locally or diffusely in the subarachnoid spaces or within the brain or ventricular system in more than 90 percent of cases and in practically all cases in which the hemorrhage has been severe enough to cause momentary or persistent loss of consciousness (Fig. 33-26). MRI also detects blood in the proton-density sequence; after a day has passed, this is also appreciated with the FLAIR sequence and some groups perform MRI in preference to CT. The blood may appear as a subtle shadow along the tentorium or in the sylvian or adjacent fissures, it is more easily appreciated in the noncontrast study. A large localized collection of subarachnoid blood or a hematoma in brain tissue or within the sylvian fissure indicates the adjacent location of the aneurysm and the likely region of subsequent vasospasm, as already


Neurology_Adams

Neurology_Adams. collection of subarachnoid blood or a hematoma in brain tissue or within the sylvian fissure indicates the adjacent location of the aneurysm and the likely region of subsequent vasospasm, as already noted. When two or more aneurysms are visualized, the CT can identify the one that had ruptured by the clot that surrounds it. Also, coexistent hydrocephalus will be demonstrable. If the CT documents subarachnoid blood with certainty, a spinal tap is not necessary.


Neurology_Adams

Neurology_Adams. In where subarachnoid hemorrhage is suspected but not apparent on imaging studies, a lumbar puncture should be undertaken. Usually the CSF becomes grossly bloody within 30 min or sooner of the hemorrhage, with RBC counts up to 1 million/mm3 or even higher, however, blood may not be easily apparent in a lumbar puncture minutes after the hemorrhage. The CSF in the first days is under increased pressure, as high as 500 mm H2O—but usually closer to 250 mm H2O—an important finding in differentiating spontaneous subarachnoid hemorrhage from a traumatic tap. With a relatively mild hemorrhage, there may be only a few thousand cells but a severe headache syndrome from subarachnoid hemorrhage is usually associated with at least several hundred cells. It is also probably not possible for an aneurysm to rupture entirely into brain tissue without some leakage of blood into the subarachnoid fluid. In other words, the diagnosis of ruptured saccular aneurysm is essentially excluded if blood is not


Neurology_Adams

Neurology_Adams. to rupture entirely into brain tissue without some leakage of blood into the subarachnoid fluid. In other words, the diagnosis of ruptured saccular aneurysm is essentially excluded if blood is not present in the CSF, provided the spinal fluid is examined more than 30 min after the event. Xanthochromia is found after centrifugation of the CSF if several hours or more have elapsed from the moment of the ictus. In a patient who reports a headache that was consistent with subarachnoid hemorrhage but that had occurred several days earlier, the CT may be normal and xanthochromia is the only diagnostic finding. To determine whether xanthochromia is present, fresh CSF must be centrifuged in a tube with a conical bottom and the supernatant compared to clear water in good light or preferably examined by spectrophotometric techniques. It has been our experience that most hospital laboratories cannot be depended on to give accurate results for this test from visual inspection alone. Also helpful


Neurology_Adams

Neurology_Adams. by spectrophotometric techniques. It has been our experience that most hospital laboratories cannot be depended on to give accurate results for this test from visual inspection alone. Also helpful after several days is the MRI taken with the FLAIR sequence as mentioned, which will demonstrate blood (the proton-density sequence is more sensitive to blood in the first day).


Neurology_Adams

Neurology_Adams. The problem of a “traumatic tap” often clouds the early diagnosis, and several aids to detecting this misleading laboratory result are discussed in Chap. 2. Here it is reiterated that in addition to the absence of xanthochromia, the most important features indicating that blood has been spuriously introduced by entering small veins in the epidural space with the lumbar puncture needle are the clearing of blood as one continues to collect fluid and a marked reduction in the number of RBCs in serial tubes of spinal fluid. A normal opening pressure also suggests puncture of a local vessel rather than a ruptured aneurysm. The combination of subarachnoid hemorrhage and a traumatic tap generally requires that vascular imaging procedures be performed to resolve the issue of the presence of an aneurysm that could potentially rerupture. In both a traumatic puncture and early in subarachnoid hemorrhage, the proportion of WBCs to RBCs in the CSF is usually the same as in the circulating blood


Neurology_Adams

Neurology_Adams. aneurysm that could potentially rerupture. In both a traumatic puncture and early in subarachnoid hemorrhage, the proportion of WBCs to RBCs in the CSF is usually the same as in the circulating blood (approximately 1:700), but in some patients with genuine hemorrhage a brisk CSF leukocytosis appears within 48 h, sometimes reaching more than 1,000 cells/mm3. The protein is slightly or moderately elevated and in some instances glucose is reduced sometimes dramatically so. Elevated CSF pressure has already been mentioned as favoring a genuine hemorrhage rather than traumatic tap.


Neurology_Adams

Neurology_Adams. Digital subtraction angiography with bilateral carotid and vertebral contrast injections is the most sensitive means of demonstrating an aneurysm. In addition to other causes of subarachnoid hemorrhage, approximately 5 to 10 percent of patients with apparent aneurysmal rupture will not have an aneurysm evident. Some of these instances may be the result of the obliteration of the lesion in the process of rupture. Patients with the typical clinical picture of spontaneous subarachnoid hemorrhage in whom an aneurysm or arteriovenous malformation cannot be demonstrated angiographically have a better prognosis than those in whom the lesion is visualized (Nishioka et al). In a series of 323 angiographically negative cases followed for an average of 10 years, there was rebleeding in only 12 (Hawkins et al). After 22 years, 69 percent of these patients had survived. If the first angiogram does not reveal an aneurysm, it is customary to repeat the study in several weeks, in part because it has


Neurology_Adams

Neurology_Adams. et al). After 22 years, 69 percent of these patients had survived. If the first angiogram does not reveal an aneurysm, it is customary to repeat the study in several weeks, in part because it has been considered that vascular spasm may have earlier obscured the aneurysm. Even when no vasospasm visualized, it is occasionally the case that a second study shows the lesion. If the first study involves all cerebral vessels and uses several views of the basal circulation, it has been our experience that the second arteriogram is infrequently revealing, but we follow general practice and repeat it nonetheless. Imaging of the spinal vasculature rarely reveals a source in these circumstances, 3 of 75 patients in a series reported by Germans and colleagues.


Neurology_Adams

Neurology_Adams. It has not been firmly established if alternative forms of imaging, namely CT and MRI angiography are as dependable as conventional angiography in excluding and aneurysm but several series suggest they may not be entirely adequate. Even when MR angiography demonstrates the aneurysm, if surgery is contemplated, the surgeon usually requires the kind of anatomic definition that can be better obtained by conventional digital subtraction angiography. CT and MRI angiographic have the potential advantages of showing the lesion in relation to the adjacent brain, soft tissue and bone in multiple views (Fig. 33-27). Digital subtraction angiography with bilateral carotid and vertebral artery contrast injections is the most sensitive means of demonstrating an aneurysm. In addition to other causes of subarachnoid hemorrhage, approximately 5 to 10 percent of patients with subarachnoid hemorrhage due to aneurysmal rupture will not have an aneurysm evident. Some of these instances may be the result


Neurology_Adams

Neurology_Adams. subarachnoid hemorrhage, approximately 5 to 10 percent of patients with subarachnoid hemorrhage due to aneurysmal rupture will not have an aneurysm evident. Some of these instances may be the result of obliteration of the lesion in the process of rupture. Patients with the typical clinical picture of spontaneous subarachnoid hemorrhage in whom an aneurysm or arteriovenous malformation cannot be demonstrated angiographically have a better prognosis than those in whom the lesion is visualized (Nishioka et al). In a series of 323 angiographically negative cases followed for an average of 10 years, there was rebleeding in only 12 (Hawkins et al). After 22 years, 69 percent of these patients had survived. If the first angiogram does not reveal an aneurysm, it is customary to repeat an angiogram in several weeks in part because it has been considered that arterial spasm may have earlier obscured the aneurysm. Even when no vasospasm is visualized, it is occasionally the case that a second


Neurology_Adams

Neurology_Adams. in several weeks in part because it has been considered that arterial spasm may have earlier obscured the aneurysm. Even when no vasospasm is visualized, it is occasionally the case that a second study shows the aneurysm. It has not been firmly established if alternative forms of arterial imaging, namely CT and MRI angiography, are as dependable as digital subtraction angiography in identifying an aneurysm but several series suggest they may not be entirely adequate. Even when CT or MR angiography demonstrates the aneurysm, if surgery is contemplated, the surgeon usually requires the kind of anatomic definition that is better obtained by conventional digital subtraction angiography. CT and MR angiographic techniques do have the potential advantage of showing the vascular lesion in relation to adjacent brain parenchyma, soft tissue, or bone (Fig. 33-26).


Neurology_Adams

Neurology_Adams. Another clinical circumstance with a favorable outcome is a limited perimesencephalic hemorrhage as described by van Gijn and colleagues. The cisterns surrounding the midbrain and upper pons are symmetrically filled with blood, the headache is mild, and signs of vasospasm do not develop. No aneurysm is found at the expected site for blood in this region, that is, at the top of the basilar artery. The patient usually does well and a second arteriogram is probably not required. It has been speculated that the bleeding has a venous rather than an arterial-aneurysmal source.


Neurology_Adams

Neurology_Adams. Rebleeding The outstanding characteristic of this condition, mentioned earlier, is the tendency for the hemorrhage to recur from the same site in more than one-third of patients, often catastrophically. This threat colors all prognostications and dominates modern treatment strategies including early obliteration of the aneurysm by surgery or endovascular techniques. There does not appear to be a way of determining reliably which patients will bleed again. The cause of recurrent bleeding is not understood but is related to naturally occurring mechanisms of clot lysis, perhaps due to factors in the CSF, at the site of initial rupture, usually at the dome of the aneurysm. Rates and timing of rebleeding are discussed further on under “Prognosis.”


Neurology_Adams

Neurology_Adams. Vasospasm Delayed hemiplegia and other deficits because of focal vasospasm usually appear 3 to 10 days after rupture and rarely before or after this period. Fisher and coworkers (1980) demonstrated that the most severe vasospasm occurs in arteries that are surrounded by collections of clotted subarachnoid blood after 24 h. These same authors devised a widely used scale that rates the extent and location of remaining clot. The reduction in the caliber of blood vessels (vasospasm) appears to be a direct effect of some blood product on the adventitia of the adjacent artery but which component of blood or another mechanism has eluded study for many decades. Areas of ischemic infarction in the territory of the vessel bearing the aneurysm, without thrombosis or other intraluminal changes in the vessel, is the usual finding in such cases. The mechanism is presumed to be purely a reduction in blood flow distal to the area of vasospasm but therefore influenced by systemic blood pressure and by


Neurology_Adams

Neurology_Adams. vessel, is the usual finding in such cases. The mechanism is presumed to be purely a reduction in blood flow distal to the area of vasospasm but therefore influenced by systemic blood pressure and by collateral circulation in the cortex. The ischemic lesions are often multiple and had in the past occurred with great frequency than they do currently according to Hijdra and associates, perhaps as a result in overall management of hemorrhage in ICUs.


Neurology_Adams

Neurology_Adams. After a few days, arteries in chronic spasm undergo a series of morphologic changes. The smooth muscle cells of the media become necrotic, and the adventitia is infiltrated with neutrophilic leukocytes, mast cells, and red blood corpuscles, some of which have migrated to a subendothelial position. One current notion is that these changes are caused by products of hemolyzed blood seeping inward from the pia-arachnoid into the muscularis of the artery.


Neurology_Adams

Neurology_Adams. The clinical features of delayed cerebral vasospasm depend on the affected blood vessel but typically include a fluctuating hemiparesis or aphasia and increasing confusion that must be distinguished from the effects of hydrocephalus (see below). In the past, an arteriogram was required to verify the diagnosis, although it is not often performed now because of the slight associated risk of worsening vascular spasm and the ease with which the condition can be recognized by its clinical presentation. Severe vasospasm is also visualized with MRA and CT techniques (Fig. 33-28). Transcranial Doppler ultrasonography measurements provide an indirect way of following, by observations of blood flow velocity, the caliber of the main vessels at the base of the brain but they are somewhat imprecise for this purpose. Almost all patients have a greatly increased velocity of blood flow in the affected vessel that can be detected by ultrasound in the days after hemorrhage. However, progressive


Neurology_Adams

Neurology_Adams. for this purpose. Almost all patients have a greatly increased velocity of blood flow in the affected vessel that can be detected by ultrasound in the days after hemorrhage. However, progressive elevation of flow velocity in any one vessel (especially if over 175 cm/s) suggests that focal vasospasm is occurring. There is a reasonable correlation between these findings and the radiographic appearance of vasospasm, but the clinical manifestations of ischemia depend on additional factors such as collateral blood supply and the cerebral perfusion pressure.


Neurology_Adams

Neurology_Adams. Hydrocephalus If a large amount of blood ruptures into the ventricular system or floods the basal subarachnoid space, it may find its way into the ventricles through the foramina of Luschka and Magendie. The patient then becomes confused or unconscious as a result of acute hydrocephalus. The clinical signs are reversed by draining the ventricles, either by external ventriculostomy or, in selected cases, by lumbar puncture, but the routine use of ventricular drainage after subarachnoid hemorrhage is not uniformly agreed upon. Delayed and subacute hydrocephalus as a result of blockage of the CSF pathways by blood may appear after 2 to 4 weeks and is managed similarly. Many of these latter cases improve. There are further instances of long-delayed hydrocephalus that present as normal-pressure hydrocephalus (NPH) months or years after subarachnoid hemorrhage, as described in Chap. 29. Anatomic–Clinical Correlations of Aneurysms


Neurology_Adams

Neurology_Adams. In most patients, the neurologic manifestations do not point to the exact site of the aneurysm, but it can often be inferred from the location of the main clot on CT. A collection of blood in the anterior interhemispheric fissure indicates rupture of an anterior communicating artery aneurysm; in the sylvian fissure, a middle cerebral artery aneurysm; in the anterior perimesencephalic cistern, a posterior communicating or distal basilar artery aneurysm. In other instances clinical signs provide clues to its localization, as follows: (1) third-nerve palsy (ptosis, diplopia, dilatation of pupil, and divergent strabismus), indicates an aneurysm at the junction of the posterior communicating artery and the internal carotid artery—the third nerve passes immediately lateral to this point or at the posterior cerebral-posterior communicating artery junction; (2) transient paresis of one or both of the lower limbs at the onset of the hemorrhage suggests an anterior communicating aneurysm that


Neurology_Adams

Neurology_Adams. the posterior cerebral-posterior communicating artery junction; (2) transient paresis of one or both of the lower limbs at the onset of the hemorrhage suggests an anterior communicating aneurysm that has interfered with the circulation in the anterior cerebral arteries; (3) hemiparesis or aphasia points to an aneurysm at the first major bifurcation of the middle cerebral artery; (4) unilateral blindness indicates an aneurysm lying anteromedially in the circle of Willis (usually at the origin of the ophthalmic artery or at the bifurcation of the internal carotid artery); (5) a state of retained consciousness with akinetic mutism or abulia favors a location on the anterior communicating artery; (6) the side on which the aneurysm lies may be indicated by a unilateral preponderance of headache or by unilateral preretinal (subhyaloid) hemorrhage (Terson syndrome), the occurrence of monocular pain, or, rarely, lateralization of an intracranial sound heard at the time of rupture of the


Neurology_Adams

Neurology_Adams. or by unilateral preretinal (subhyaloid) hemorrhage (Terson syndrome), the occurrence of monocular pain, or, rarely, lateralization of an intracranial sound heard at the time of rupture of the aneurysm. Sixth-nerve palsy, unilateral or bilateral, is usually attributable to raised intracranial pressure and is less often of localizing value.


Neurology_Adams

Neurology_Adams. Other clinical data may be of assistance in reaching a correct diagnosis. Levels of blood pressure of 200 mm Hg systolic are seen occasionally just after rupture, but usually the pressure is elevated only moderately and fluctuates with the degree of head pain. Nuchal rigidity is usually present but occasionally absent, and the main complaint of pain may be referable to the interscapular region or even the low back rather than to the head. Examination of the fundi frequently reveals smooth-surfaced, sharply outlined collections of blood that cover the retinal vessels—preretinal or subhyaloid hemorrhages (Terson syndrome); Roth spots are seen occasionally. Bilateral Babinski signs are found in the first few days following rupture if there is hydrocephalus. Fever up to 39°C (102.2°F) may be seen in the first week, but most patients are afebrile. Rarely, escaping blood enters the subdural space and produces a hematoma, evacuation of which may be lifesaving.


Neurology_Adams

Neurology_Adams. In summary, the clinical sequence of sudden severe headache, vomiting, collapse, relative preservation of consciousness with few or no lateralizing signs, and neck stiffness is diagnostic of subarachnoid hemorrhage caused by a ruptured saccular aneurysm. Vasospasm, hydrocephalus and particularly, rerupture follow and dominate prognosis in survivors. Acute subarachnoid hemorrhage is associated with several characteristic responses in the systemic circulation, water balance, and cardiac function. The ECG changes include symmetrically large peaked T waves (“cerebral


Neurology_Adams

Neurology_Adams. T waves”) and other alterations, suggesting subendocardial or myocardial ischemia. There may be a minor elevation of troponin and the myocardial band (MB) of creatine phosphokinase (CPK). In some patients, the cardiac dysfunction is severe enough to seriously reduce the ejection fraction and cause heart failure. There is a tendency to develop hyponatremia (Wijdicks et al); this abnormality and its relationship to intravascular volume depletion play a key role in treatment, as discussed further on. Albuminuria and glycosuria may be present for a few days. Rarely, diabetes insipidus occurs in the acute stages, but water retention or a natriuresis is more frequent. There may be a leukocytosis of 15,000 to 18,000 cells/mm3, but the sedimentation rate and C-reactive protein are usually normal, or any elevation is attributable to another cause. As regards prognosis of aneurysmal hemorrhage,


Neurology_Adams

Neurology_Adams. McKissock and colleagues decades ago found that the patient’s state of consciousness at the time of arteriography was the single best index of outcome, and this remains largely true today. Their data, representative of the status of aneurysm management in the 1950s and consonant with the natural history before the advent of modern surgical and intensive care techniques, indicated that of every 100 patients reaching a hospital and coming to arteriography, 17 were stuporous or comatose and 83 appeared to be recovering from the ictus. At the end of 6 months, 8 of every 100 patients had died of the original hemorrhage and 59 had a recurrence (with 40 deaths), making a total of 48 deaths and 52 survivors. In regard to recurrence of bleeding, it was found that of 50 patients seen on the first day of the illness, 5 rebled in the first week (all fatal), 8 in the second week (5 fatal), 6 in the third and fourth weeks (4 fatal), and 2 in the next 4 weeks (2 fatal), making a total of 21


Neurology_Adams

Neurology_Adams. first day of the illness, 5 rebled in the first week (all fatal), 8 in the second week (5 fatal), 6 in the third and fourth weeks (4 fatal), and 2 in the next 4 weeks (2 fatal), making a total of 21 recurrences (16 fatal) in 8 weeks.


Neurology_Adams

Neurology_Adams. A comprehensive and still instructive, but now dated, long-term analysis of the natural history of the disease is contained in the report of the Cooperative Study of Intracranial Aneurysms and Subarachnoid Hemorrhage (Sahs et al, 1984). The study was based on long-term observations of 568 patients who sustained an aneurysmal bleed between 1958 and 1965 and were managed only by a conservative medical program. A followup search in 1981 and 1982 disclosed that 378, or two-thirds of the patients, had died; 40 percent of the deaths had occurred within 6 months of the original hemorrhage. For the patients who survived the original hemorrhage for 6 months, the chances of survival during the next two decades were significantly worse than those of a matched normal population. Rebleeding occurred at a rate of 2.2 percent per year during the first decade and 0.86 percent per year during the second, and these were fatal in 78 percent of cases. Although these statistics reflect the outcome prior


Neurology_Adams

Neurology_Adams. at a rate of 2.2 percent per year during the first decade and 0.86 percent per year during the second, and these were fatal in 78 percent of cases. Although these statistics reflect the outcome prior to the modern era of microsurgery and neurologic intensive care management, current figures are only modestly better. In respect to rebleeding, all series indicate that the risk is greatest in the first day but extends for weeks. The observations of Aoyagi and Hayakawa are representative of other series; they found that rebleeding occurred within 2 weeks in 20 percent of patients, with a peak incidence in the 24 h after the initial episode. Surgical treatment is largely oriented toward reducing this complication.


Neurology_Adams

Neurology_Adams. In a prospective clinical trial conducted by the International Cooperative Study in 1990 and based on observations of 3,521 patients (surgery performed in 83 percent), it was found at the 6-month evaluation that 26 percent had died and 58 percent had made a good recovery (Kassell et al). Vasospasm and rebleeding were the leading causes of morbidity and mortality in those who survived the initial hemorrhage. More recent series, usually from one country or one center, generally reflect these statistics except that rebleeding has been less frequent as earlier intervention has become more generally applied. This is influenced by the neurologic and general medical state of the patient as well as by the location and morphology of the aneurysm. Ideally, all patients should have the aneurysmal sac obliterated, but the mortality is high if the patient is stuporous or comatose (Hunt and Hess scale IV or V).


Neurology_Adams

Neurology_Adams. The general medical management in the acute stage includes bed rest, fluid administration to maintain above-normal circulating blood volume and central venous pressure; use of elastic stockings and stool softeners; administration of calcium channel blockers to reduce infarction from vasospasm (see below); additional beta-adrenergic blockers, intravenous nitroprusside, or other medication to reduce greatly elevated blood pressure and then maintain systolic blood pressure at 150 mm Hg or less; and pain-relieving medication for headache (this alone will often reduce the hypertension). The prevention of systemic venous thrombosis is critical; it usually is accomplished by the use of cyclically inflated whole-leg compression boots. The use of antiepileptic drugs is controversial; many neurosurgeons administer them early, with a view of preventing a seizure-induced risk of rebleeding. Several small studies suggest they may be detrimental and we have generally avoided them unless a seizure


Neurology_Adams

Neurology_Adams. administer them early, with a view of preventing a seizure-induced risk of rebleeding. Several small studies suggest they may be detrimental and we have generally avoided them unless a seizure has occurred.


Neurology_Adams

Neurology_Adams. Calcium channel blockers are used to reduce the incidence of stroke from vasospasm. Nimodipine 60 mg administered orally every 4 h is currently favored. Although calcium channel blockers do not alter the incidence of angiographically demonstrated vasospasm, they have reduced the number of strokes in each of five randomized studies, beginning with the one conducted by Allen and colleagues. Several groups use angioplasty techniques to dilate vasospastic vessels and report symptomatic improvement, but there are as yet insufficient controlled data to judge the merits and safety of this procedure.


Neurology_Adams

Neurology_Adams. The most notable advances in this disease have been in the techniques for the early obliteration of aneurysms, particularly the operating microscope and endovascular approaches, and in the management of circulatory volume. In the majority of patients, intravascular volume is depleted in the days after subarachnoid hemorrhage. This, in turn, greatly increases the chances of ischemic infarction from vasospasm. In part, this volume contraction can be attributed to bed rest, but sodium loss, probably resulting from the release of atrial natriuretic factor (ANF), a potent oligopeptide stimulator of sodium loss in renal tubules, may also be a factor. Hyponatremia develops in the first week after hemorrhage, but it is unclear whether this also results from the natriuretic effects of ANF or is an effect of antidiuretic hormone, causing water retention. The work of Diringer and coworkers (1988) suggests that both mechanisms are operative but it is the volume depletion, not hyponatremia per se,


Neurology_Adams

Neurology_Adams. effect of antidiuretic hormone, causing water retention. The work of Diringer and coworkers (1988) suggests that both mechanisms are operative but it is the volume depletion, not hyponatremia per se, that is of the greatest clinical consequence.


Neurology_Adams

Neurology_Adams. Both the risk of rerupture of the aneurysm and some of the secondary problems that arise because of blood in the subarachnoid space can be obviated by early obliteration of the aneurysm. Because of the changes in water balance and the risk of delayed stroke from vasospasm, there has been an emphasis on early volume expansion and sodium repletion by the intravenous infusion of crystalloids. As Solomon and Fink have pointed out, this can be accomplished without fear of aneurysmal rupture if blood pressure is allowed to rise only minimally. Of course, fluid replacement and a modest elevation of blood pressure become completely safe if the aneurysm has been surgically occluded. Because of the current approach of ablating the aneurysm early, the previously popular use of antifibrinolytic agents as a means of impeding lysis of the clot at the site of aneurysmal rupture has been generally abandoned. Repeated drainage of the CSF by lumbar puncture is also no longer practiced as a routine. One


Neurology_Adams

Neurology_Adams. as a means of impeding lysis of the clot at the site of aneurysmal rupture has been generally abandoned. Repeated drainage of the CSF by lumbar puncture is also no longer practiced as a routine. One lumbar puncture is generally carried out for diagnostic purposes if the CT is inconclusive; thereafter, spinal fluid drainage is performed only for the relief of intractable headache or to detect recurrence of bleeding. As mentioned earlier, patients with stupor or coma who have massive hydrocephalus often benefit from decompression of the ventricular system. This is accomplished initially by external drainage and may require permanent shunting if the hydrocephalus returns. The common practice of draining milder degrees of hydrocephalus has not been proven to be helpful. Some risk may attend rapid removal of CSF by this method or lumbar puncture but some centers still undertake it. The risk of infection of the external shunt tubing is high if it is left in place for much more than 3 days.


Neurology_Adams

Neurology_Adams. removal of CSF by this method or lumbar puncture but some centers still undertake it. The risk of infection of the external shunt tubing is high if it is left in place for much more than 3 days. Replacement with a new drainage tube, preferably at another site, reduces this risk.


Neurology_Adams

Neurology_Adams. Obliteration of the aneurysm The current approach is to operate or eliminate the aneurysm by endovascular means early, within 24 h if possible, for patients who are in Hunt and Hess grades I and II, and then to increase intravascular volume and maintain normal or above-normal blood pressures. This precludes rebleeding, with its high mortality, and ameliorates the second cause of morbidity, stroke from vasospasm.


Neurology_Adams

Neurology_Adams. The timing of surgery or endovascular treatment for grade III patients is still controversial but if their medical condition allows, they, too, probably benefit from the same early and aggressive approach. In grade IV patients, the outcome is generally dismal, no matter what course is taken, but we have usually counseled against early operation; some neurosurgeons disagree. The insertion of ventricular drains into both frontal horns has occasionally raised a patient with severe hydrocephalus to a better grade and facilitated early operation. In the hands of experienced anesthesiologists and cerebrovascular surgeons, the operative mortality, even in grades III and IV patients, has now been reduced to 2 to 3 percent.


Neurology_Adams

Neurology_Adams. Several alternative measures are in common use for this purpose. Endovascular obliteration of the lumen of the aneurysm has become the preferred approach for most aneurysms and is strongly favored for those not easily accessible by surgery, for example, in the cavernous sinus—and for patients whose medical state precludes an operation. Among several trials that have compared surgery with endovascular placement of coils in the aneurysm, most have shown equivalence or a slight superiority of the latter. For example, the International Subarachnoid Aneurysm Trial Group, reported by Molyneux and colleagues, randomly assigned more than 2,000 patients to surgery or coil deployment; the overall rate of death or dependence at 1 year was 24 percent in the endovascular group and 31 percent in the operated group, a difference that was sustained at 2 years of follow up. A single center trial reported by Spetzler and colleagues (2013) had less restrictive entry criteria but favored endovascular


Neurology_Adams

Neurology_Adams. operated group, a difference that was sustained at 2 years of follow up. A single center trial reported by Spetzler and colleagues (2013) had less restrictive entry criteria but favored endovascular treatment overall in outcome at 1 year; by 3 to 6 years the clinical outcomes of the surgical and endovascular groups were similar. Certain features of the aneurysm may dictate that surgery or endovascular treatment is not possible and the alternative is therefore favored. It is self-evident that the skill of the surgeon or interventionalist and the quality of postoperative care are major determinants of outcome.