Suppressed sympathetic skin response in brain infarction.

BACKGROUND AND PURPOSE Autonomic failure is known to manifest commonly in stroke, but very little attention has been given to various features of sympathetic dysfunction such as sudomotor dysregulation in cerebrovascular diseases. In the present study, our purpose was to assess quantitatively sympathetic reflex activity in brain infarction by measuring the sympathetic skin response. METHODS We recorded the sympathetic skin response to electric and auditory stimulations simultaneously on both hands in 58 patients with brain infarction and in 36 healthy control subjects. RESULTS The response amplitudes were significantly decreased and the latencies prolonged in both hemispheral (n = 49) and brain stem (n = 9) infarctions compared with the control subjects. The amplitudes were diminished in both the acute and late phases of infarction, but the latencies were prolonged only in the acute phase. CONCLUSIONS Sympathetic dysfunction in brain infarction seems to be much more extensive than has previously been thought. In the present study, we have demonstrated impaired sympathetic skin responses, reflecting definite suppression of the reflex activity of the sympathetic nervous system.