Sympathetic skin response in carpal tunnel syndrome

Sympathetic skin response [SSR] is most frequently used in diagnosing functional impairment of non-myelinated postganglionic sympathetic fibers. Early diagnosis of autonomic dysfunction is important in patients with carpal tunnel syndrome [CTS] as the earlier the diagnosis the more effective the treatment. Aim of this work was to measure the SSR in patients with CTS to detect its relation with possible autonomic dysfunction. This study included 18 patients [23 hands] with CTS, graded according to Bland [2000]. SSR measurement was done, and the latency and amplitude were measured. Clinical manifestations of autonomic dysfunction were present in 6 hands [26%]. There was statistically high significant longer disease duration among patients with autonomic dysfunction in comparison to those without. Among our patients, 3 hands [13%] had no elicited SSR. This was associated with very severe carpal tunnel syndrome, female sex, and long disease duration. There was a statistically high significant difference between patients and controls as regards the latency of SSR with no significant difference as regards the amplitude. There was a statistically high significant positive correlation between the SSR latency and the grading of CTS, and statistically high significant negative correlation between the amplitude of SSR and the grading of CTS. SSR can be used in the electrodiagnostic workup for patients with carpal tunnel syndrome where it can be used as a method for detection of autonomic dysfunction in these patients