Case number: 173

the way of the cross

Author: Jason Barton

This 39 year old woman was seen in the intensive care unit for a visual assessment.

She had been admitted to hospital with neck pain and lethargy, with dilated pupils on exam. Her level of consciousness deteriorated, she developed fever and bilateral leg weakness, and was intubated. Her cerebrospinal fluid showed a white count of 425 cells (88% polymorphonuclear cells), <500 red cells, protein of 381 mg/dL, glucose of 1.0 mmol/L, and she required an extraventricular drain for hydrocephalus. She was given intravenous steroids and antibiotics.

On neuro-ophthalmologic review 10 days later she had no pupil light reactions with a 1mm anisocoria, larger on the right, with mild right ptosis, exotropia and right hypotropia. MRI images are shown.

Question: what visual and neurologic deficits do you predict from the imaging? What do you think her underlying condition is? Send your answers to us! (Jason Barton)

View Diagnosis

BIindness from bilateral optic tract damage, amnestic syndrome

Her cerebrospinal fluid is highly suspicious for bacterial meningitis, and PCR testing was positive for pneumococcus.  There is hyperintense signal involving the mamillary bodies and the adjacent optic tracts.

Bilateral mamillary body lesions are rare, most famously from thiamine deficiency in Wernicke-Korsakoff syndrome (1).  These can cause an acute confusional state that transitions into a chronic amnestic disorder with confabulation. Indeed, as she recovered from her ICU stay, it became apparent that she had a profound anterograde and retrograde memory deficit.  In addition, she was blind and having occasional visual hallucinations. Her ocular motor features suggest a partial right III nerve palsy.

Pneumococcal meningitis is well known for its propensity to cause cranial neuropathies.  The most frequent residual complication is deafness, which even in developed countries occurs in 20% of cases, whereas other cranial nerve palsies occur in about 10%, and visual loss is the least common, occurring in 2.4% (2). Optic chiasmitis has been reported (3), which is not dissimilar to our case of bilateral optic tract damage. Endophthalmitis is another rare cause of visual loss with pneumococcal disease (4).


  1. Sinha S, Kataria A, Kolla BP, Thusius N, Loukianova LL. Wernicke Encephalopathy-Clinical Pearls. Mayo Clin Proc. 2019 Jun;94(6):1065-1072.
  2. Jit M. The risk of sequelae due to pneumococcal meningitis in high-income countries: a systematic review and meta-analysis. J Infect. 2010 Jul;61(2):114-24.
  3. Şahin S, Kola M, Cansu A, Kul S, İmamoğlu Hİ. Chiasmal optic neuritis may be secondary to pneumococcal meningitis: a child with acute monocular vision loss. Neurol Sci. 2016 Jan;37(1):139-141.
  4. Torii H, Miyata H, Sugisaka E, Ichikawa Y, Shinoda K, Inoue M. Bilateral endophthalmitis in a patient with bacterial meningitis caused by Streptococcus pneumoniae. Ophthalmologica. 2008;222(5):357-9.