Normative data of sympathetic skin response and RR interval variation in Turkish children

Sympathetic skin response (SSR) and RR interval variation (RRIV) are used c ommonly for the assessment of sympathetic and parasympathetic nervous syste m function, respectively. We determined the normal values of SSR and RRIV i n 23 (14 females, nine males) Turkish children aged 5 to 14 (mean 9.86, SD 2.48) years. SSR was recorded on the hands and feel during the electrical s timulation of both median and posterior tibial nerves, respectively. Simila r response was elicited on both feet during the stimulation of the right me dian nerve. RRIV testing was performed during rest on the supine position a nd deep inspiration at a frequency of 6 times/min. The SSR was elicited in all children. The mean SSR latencies recorded on the feet during the stimul ation of median or posterior tibial nerve were significantly more prolonged than those recorded at the hands (P < 0.001). There was no significant dif ference between the mean latencies of SSR recorded at the ipsilateral and c ontralateral palms or soles. The mean latencies recorded at the sole during stimulation of the median nerve were not significantly different compared to those that recorded at the sole during the posterior tibial nerve(P > 0. 05). The SSR amplitudes were not assessed because of great variability and rapid habituation. The mean RRIV (46.54 +/- 11.29%) during deep breathing w as significantly increased as compared to that (35.90 +/- 10.63%) during re st (P < 0.003). As a result, SSR and RRIV are preferred non-invasive tests for evaluation of autonomic nervous system in children. The SSR is useful a nd reliable if it is obtained in the optimum technical conditions. Further research is necessary to establish strict criteria for abnormality. (C) 199 9 Elsevier Science B.V. All rights reserved.