Autonomic involvement in Wilson's disease: a study of sympathetic skin response and RR interval variation

Autonomic nervous system involvement in Wilson's disease (WD) was studied in 25 patients by sympathetic skin response (SSR) and RR interval variation (RRIV). The control group consisted of age-matched healthy subjects. Palmar SSRs were obtained by central activation from median nerve stimulation and by activation of sympathetic trunk from magnetic stimulation of the neck. Electric SSRs were prolonged in 11 patients and absent in 2; magnetic SSRs were delayed in 4 and absent in 1; and the sympathetic central conduction time was prolonged in 3. The mean latencies and mean central conduction of the SSRs were all significantly prolonged in WD when compared to the control group. On the other hand, parasympathetic function was abnormal in 3 patients only during forced deep breathing, and as a group only mean D% was significantly reduced. The present findings suggest that autonomic dysfunction may occur in WD, and that sympathetic function is predominantly affected, mainly due to central involvement.