SYMPATHETIC SKIN-RESPONSES RECORDED FROM NON-PALMAR AND NON-PLANTAR SKIN SITES - THEIR ROLE IN THE EVALUATION OF THERMAL SWEATING

Objective: To characterize the sympathetic skin responses (SSRs) recor ded from non-palmar and non-plantar (non-Pa/Pl) skin sites and to eval uate their clinical usefulness. Methods: SSRs were recorded from 6 non -Pa/PI sites as well as palmar and plantar (Pa/Pl) sites using magneti c neck stimulation in 33 normal subjects, 17 neurological patient with dysautonomia and one patient with lumbar sympathectomy. A conventiona l thermoregulatory sweat test (TST) was also carried out in 3 patients . Results: Clear and reproducible SSRs were obtained from ail recordin g sites in all of the normal subjects when the shin temperatures of th e subjects were maintained above 34 degrees C and the subjects drank 1 00-200 ml of hot water. The distribution of absent SSRs was closely co rrelated with that of anhidrosis or a sweating delay shown by the TST in the patients. Nine of the 17 neurological patients (53%) showed nor mal responses at Pa/Pl sites, and abnormal responses at non-Pa/Pl site s. Conclusions: Recording SSRs from multiple skin sites including non- Pa/Pl sites after magnetic stimulation is more sensitive in detecting sudomotor dysfunction than is the conventional method of recording SSR s from only Pa/Pl sites. In addition, this new method is very useful f or the objective clinical evaluation of thermal sweating. (C) 1998 Els evier Science Ireland Ltd. All rights reserved.