Sympathetic skin response in patients with cerebellar degeneration.

Sudomotor function was studied based on sympathetic skin responses (SSRs) in 87 patients with various types of cerebellar degeneration. Evaluations of orthostatic hypotension and the R-R interval variation were also performed in these patients. The respective incidences of SSR abnormality and orthostatic hypotension were 44 (50.6%) of 87 and 39 (44.8%) of 87. Fourteen percent of the patients with abnormal SSRs did not have orthostatic hypotension, but 8% of the patients with normal SSRs did have orthostatic hypotension. Sympathetic skin responses were abnormal in most patients with Shy-Drager syndrome, sporadic olivopontocerebellar atrophy (OPCA), and striatonigral degeneration, whereas SSRs were normal in patients with familial OPCA, sporadic cerebellar atrophy, and familial cerebellar atrophy. We demonstrated that SSR can be used to evaluate sudomotor function in degenerative disorders of the central nervous system as well as in peripheral neuropathies. The vasomotor and sudomotor functions usually are both disturbed in patients with cerebellar degeneration, and the SSR can detect autonomic dysfunction as sensitively as does the head-up tilt test. We also concluded that sporadic OPCA differs from familial OPCA in that it has a much higher incidence of autonomic dysfunction and that degeneration of the cerebellar cortex did not affect the autonomic regulation.