A quantitative evaluation of pontine volume by computed tomography in patients with cerebellar degeneration.

We used CT to make a quantitative evaluation of the pontine volumes of 55 patients with adult-onset cerebellar degeneration and compared the results with their clinical records. Patients with pontine atrophy showed significantly more autonomic dysfunction and extrapyramidal signs; their other clinical features did not differ from patients without pontine atrophy. After dividing the patients into 2 groups, those with and without autonomic dysfunction or extrapyramidal signs, we found that those with these manifestations also had pontine atrophy, a later onset and shorter duration of the disease, and impairment of higher brain functions. The group without these manifestations had relatively normal pontine volume, a greater familial tendency for cerebellar degeneration, and longer duration of the disease. Our results suggest that quantitative volume evaluation of the pons by CT is important for the clinical categorization of cerebellar degeneration.