History
Mr. Chow was a 45-year-old man with a history of chronic ischemic heart disease. He is a chronic smoker and non-drinker.
He presented with a 1-year history of insidious onset, slowly progressive, unsteady gait. There were no symptoms of sensory and autonomic dysfunction.
He does not have a positive family history of gait disturbances, dementia, or seizures.
Physical examination
Clinical examination was remarkable for a broad-based gait, failed tandem walking, and limb ataxia.
There was no nystagmus, impaired sensation, ankle clonus, or abnormal Romberg’s sign.
Investigations
Baseline blood work was normal, as were the inflammatory markers and screening tests for syphilis and HIV.
A plain CT of the brain demonstrated disproportional bilateral cerebellar atrophy.
Thought process
The pathology was likely localized to the bilateral cerebellum. Importantly, there were no clinical features suggestive of a posterior column cord syndrome or peripheral polyneuropathy.
Given the chronicity of the symptoms and slow progression, the etiology was most likely due to toxic-metabolic, genetic, or neurodegenerative causes.
Next steps
Blood tests were sent for thyroid function, vitamin B12, thiamine, ammonia, lactate, ceruloplasmin, mercury, and lead.
A contrast MRI brain was arranged to look for features of neurodegenerative cerebellar syndromes, such as multiple system atrophy.
Genetic testing was referred to screen for hereditary cerebellar syndromes, including spinocerebellar ataxia and Friedreich’s ataxia.
Lumbar puncture was deferred as infective and inflammatory causes were deemed to be less likely.