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Cerebellar Disorders


Hector A. Gonzalez-Usigli

, MD, HE UMAE Centro Médico Nacional de Occidente



(See also Overview of Movement and Cerebellar Disorders.)

The cerebellum has 3 parts:



Ataxia is the archetypal sign of cerebellar dysfunction, but many other motor abnormalities may occur (see table Signs of Cerebellar Disorders).

Signs of Cerebellar Disorders




Reeling, wide-based gait

Decomposition of movement

Inability to correctly sequence fine, coordinated acts


Inability to articulate words correctly, with slurring and inappropriate phrasing


Inability to perform rapid alternating movements


Inability to control range of movement


Decreased muscle tone



Scanning speech



Rhythmic, alternating, oscillatory movement of a limb as it approaches a target (intention tremor) or of proximal musculature when fixed posture or weight bearing is attempted (postural tremor); characterized by high amplitude and low frequency

Etiology of Cerebellar Disorders

The most common cause of cerebellar disorders is

  • Alcoholic cerebellar degeneration

Congenital malformations

Such malformations are almost always sporadic, often occurring as part of complex malformation syndromes (eg, Dandy-Walker malformation) that affect other parts of the central nervous system (CNS).


Hereditary ataxias


Friedreich ataxia results from a gene mutation causing abnormal repetition of the DNA sequence GAA in the FXN gene on the long arm of chromosome 9; the FXN gene codes for the mitochondrial protein frataxin. The GAA sequence is repeated 5 to 38 times within the FXN gene in people who do not have Friedreich ataxia; however, in people with Friedreich ataxia, the GAA sequence may be repeated 70 to > 1000 times (1). Inheritance is autosomal recessive. Decreased frataxin levels lead to mitochondrial iron overload and impaired mitochondrial function.


Spinocerebellar ataxias (SCAs) are the main autosomal dominant ataxias. Classification of these ataxias has been revised many times recently as knowledge about genetics increases. Currently, at least 43 different gene loci are recognized; about 10 involve expanded DNA sequence repeats. Some involve a repetition of the DNA sequence CAG that codes for the amino acid glutamine, similar to that in Huntington disease.


SCA type 3, formerly known as Machado-Joseph disease, may be the most common dominantly inherited SCA worldwide. Symptoms include ataxia, parkinsonism, and possibly dystonia, facial twitching, ophthalmoplegia, and peculiar bulging eyes.

Acquired conditions

Acquired ataxias may result from nonhereditary neurodegenerative disorders (eg, multiple system atrophy), systemic disorders, multiple sclerosis, cerebellar strokes, repeated traumatic brain injury, or toxin exposure, or they may be idiopathic. Systemic disorders include alcoholism (alcoholic cerebellar degeneration), thiamin deficiency, celiac disease, heatstroke, hypothyroidism, and vitamin E deficiency.

Toxins that can cause cerebellar dysfunction include carbon monoxide, heavy metals, lithium, phenytoin, and certain solvents. Toxic levels of certain drugs (eg, antiseizure drugs, sedatives in high doses) can cause cerebellar dysfunction and ataxia.

Rarely, subacute cerebellar degeneration occurs as a paraneoplastic syndrome in patients with breast cancer, ovarian cancer, small cell carcinoma of the lung, or other solid tumors. Cerebellar degeneration may precede the discovery of the cancer by weeks to years. Anti-Yo, now called PCA-1 (Purkinje cell cytoplasmic antibody type 1) is a circulating autoantibody that occurs in the serum or cerebrospinal fluid (CSF) of some patients, especially women with breast or ovarian cancer.


Etiology reference

  • 1. Pandolfo M: Friedreich ataxia. Arch Neurol. 65 (10):1296–1303, 2008. doi:10.1001/archneur.65.10.1296.

Diagnosis of Cerebellar Disorders

  • Clinical evaluation
  • Typically MRI
  • Sometimes genetic testing

Diagnosis of cerebellar disorders is clinical and includes a thorough family history and search for acquired systemic disorders.


Treatment of Cerebellar Disorders

  • Treatment of the cause if possible
  • Usually only supportive

Some systemic disorders (eg, hypothyroidism, celiac disease) and toxin exposure can be treated; occasionally, surgery for structural lesions (tumor, hydrocephalus) is beneficial. However, treatment is usually only supportive (eg, exercises to improve balance, posture, and coordination; devices to help with walking, eating, and other daily activities).

Treatment reference

  • 1. Zesiewicz TA, Wilmot G, Kuo SH, et al: Comprehensive systematic review summary: Treatment of cerebellar motor dysfunction and ataxia. Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology. Neurology 90 (10):464–471, 2018. doi: 10.1212/WNL.0000000000005055.

Drugs Mentioned In This Article

Drug Name Select Trade
phenytoin DILANTIN
lithium LITHOBID
