Fifty three diabetic patients were investigated to determine the sensitivity of the sympathetic skin response test (SSR) for detection of sudomotor dysfunction and its clinical correlation with other autonomic function tests, autonomic symptoms and degree of peripheral neuropathy.
SSR was absent in both hands and both feet in 15 of 53 patients (28.3%). SSR was absent only in both feet in 17 of 53 patients (32.1%). Nerve conduction velocities (NCV) were abnormal in 30 of 53 patients (56.6%). Valsalva test was abnormal in 12 of 52 (23.1%) who had the test, and orthostatic hypotension was present in 13 of 53 patients (24.5%). Statistically significant correlation was found between nerve conduction velocity, Valsalva test, and the SSR. Autonomic symptoms and orthostatic hypotension did not have significant correlation with the SSR.
These results suggest that the SSR is a valuable and sensitive test for early detection of dysautonomia in diabetic patients.