SYMPATHETIC SKIN-RESPONSE AND CARDIOVASCULAR AUTONOMIC FUNCTION-TESTSIN DISEASE,PARKINSONS

Autonomic dysfunction commonly occurs in Parkinson's disease, but the pathogenesis of autonomic dysregulation remains uncertain. Autonomic f unctions regulating the cardiovascular system have been investigated i n Parkinson's disease, but those involving the extremities has not bee n well demonstrated. To compare autonomic dysfunctions of the cardiova scular system with those of the extremities, we performed sympathetic skin response (SSR) and cardiovascular autonomic function tests (CAFT) - 30:15 ratio, E:I ratio, Valsalva ratio, isometric exercise test (IE T) - in 37 patients with Parkinson's disease and 33 age- and sex-match ed healthy controls. The patients were asked to stop antiparkinsonian medications for at least 12 hours prior to the tests. SSR was measured at the right hand and foot after electrical stimulation of the right median and posterior tibial nerves. Absent SSR at either one or both e xtremities and CAFT beyond normal ranges were regarded as abnormal. Ab normal SSR was observed in 59% of patients, while abnormal CAFT were f ound in the range of 32% similar to 81%. Patients with abnormal SSR sh owed more frequent and severe CAFT abnormalities than did patients wit h normal SSR Among the CAFT, IET was well correlated with the SSR The results suggest that parkinsonian sympathetic dysfunction involving ei ther the cardiovascular system or the extremities may have the same pa thophysiology.