Sympathetic Skin Response and R-R Interval Variation in Cerebral Infarctions

Objective: Autonomic dysfunctions are frequently encountered manifestations in patients with cerebrovascular diseases, however, few autonomic tests have been developed to evaluate strokes patients. The purpose of the present study was to assess the autonomic nervous system function after cerebral infarction by measuring both sympathetic skin response (SSR) and R-R interval variation (RRIV). Patients and Methods: Fifty-six patients with cerebral infarctions and 52 age-matched control subjects were enrolled in this study. We performed SSR for the assessment of sympathetic sudomotor function and RRIV for cardiac parasympathetic function. Results: The SSRs were obtainable in 39 patients. The mean SSR amplitude values had significantly decreased in patients with cerebral infarctions compared with the control subjects. The SSR amplitudes were more diminished during the early phase of the infarction. The SSR abnormalities were more marked in those with left hemispheric stroke than in those with right hemispheric stroke. Similarly, RRIV had decreased in stroke patients when compared with controls and greater decreases were noticed during the early phase of infarction. Decreased RRIV values were found in patients with right hemispheric strokes compared with control subjects. No such differences were found in patients with left hemispheric strokes. Conclusions: Suppression of sympathetic sudomotor activity was more apparent in patients with left cerebral infarctions. Patients with right cerebral infarctions had greater inhibitory effects upon cardiac parasympathetic activity. (Tzu Chi Med J 2003; 15:149-154)