The sympathetic skin response(SSR) is a simple test to assess sympathetic nerve function through sudomotor activity after electric stimulation. However the electrophysiologic characteristics of sympathetic skin response have not been fully documented regardless of the impending necessities. To understand the characteristics of central conduction of SSR by taking SSRs in various central nervous system diseases, 336 SSRs were measured in 14 stroke patients, 6 spinal cord injury patients and 2 traumatic brain injury patients and analysed by classifying into no response(NR), slight and normal groups.

In stroke patients, normal SSRs were obtained more in hemiplegic side than non-hemiplegic side after both limb stimulations. And normal SSR were obtained more in left hemiplegic patients than right hemiplegic patients even though number of subject was limited. The patterns of SSR in traumatic brain injured and spinal cord injured patients were not so closely correlated with severity of clinical symptoms and abnormal somatosensory evoked potentials.

The sympathetic skin response seems to be exclusively under the control of central nervous system of which the subcortex would be regarded as the sudomotor reflex center.