SYMPATHETIC SKIN-RESPONSES (SSRS) IN MONOFOCAL BRAIN-LESIONS - TOPOGRAPHICAL ASPECTS OF CENTRAL SYMPATHETIC PATHWAYS

Lesions of the central sympathetic pathways are likely to be of clinic al relevance. In patients with acute stroke, in particular, they may b e responsible for the partially deleterious cardiac arrhythmia. There is little knowledge of the central organization of sympathetic pathway s above the brainstem level for both cardio-efferent and sudomotor fib ers. We studied the sympathetic skin response (SSR) in 29 patients wit h brainstem stroke or infarction in the territory of the middle cerebr al artery (MCA) in order to evaluate the pathways mediating emotional sweating. In 24 patients (82.8%) the SSR was pathological. These abnor malities were bilateral with no clear asymmetry in 10 patients (34.5%) , bilateral with marked contralateral pathology in 8 patients (27.6%), purely contralateral in 5 patients (17.2%) and purely ipsilateral in one patient (3.5%). Bilateral abnormalities were more frequent and mor e marked in brainstem than in MCA stroke. This is probably indicative of a more generalized sympathetic dysfunction. In contrast, contralate ral abnormalities were more pronounced in MCA than in brainstem infarc ts. Our results show that sympathetic skin responses are suppressed in the majority of stroke patients. Asymmetric responses may indicate th at sudomotor fibers mediating emotional sweating have their origin or receive input from the contralateral MCA territory.