THE SYMPATHETIC SKIN-RESPONSE IN THE SHOULDER HAND SYNDROME COMPLICATING TETRAPLEGIA

To determine the utility of the sympathetic skin response (SSR) in stu dying sympathetic outflow in cervical spinal cord injury (CSCI) patien ts who develop features of reflex sympathetic dystrophy, we studied se ven consecutive CSCI patients with the shoulder-hand syndrome (SHS), a nd seven patients with similar injuries but without the manifestations of the SHS. The mean SSR amplitude was more than three times greater in patients with the SHS, a statistically significant difference. We r estudied six patients with a SHS after symptoms had improved following steroid treatment: the mean amplitude fell significantly, approaching the mean for the control group. When pain was asymmetric, the SSR amp litude was higher in the arm with greater pain. Four of the seven SHS patients demonstrated an unusual pattern of spontaneous cyclical elect rical activity during a period of severe pain. We conclude that a SHS complicating CSCI is associated with increased amplitude of the SSR, s upporting the theory that sympathetic hyperactivity is important in th e pathophysiology of reflex sympathetic dystrophy in this setting.