Electrophysiologic evaluation of autonomic function in cerebral palsy

The presence of clinical autonomic dysfunction in patients with neurologic diseases, such as multiple sclerosis, Parkinson's disease, and cerebrovascular accident, has become increasingly recognized in the past decade. Very few autonomic tests have been done on pediatric patients thus far. The purpose of this study was to investigate the autonomic function in patients with cerebral palsy using two noninvasive tests: sympathetic skin response (SSR) and R-R interval variation (RRIV). Twenty-four patients with cerebral palsy and 24 control subjects between the ages of 4 and 12 yr were enrolled in this study. There was no significant difference of mean latency, amplitude, or amplitude ratio of SSR between the two groups under electric stimulus, startling stimulus, and deep breathing conditions. No significant difference in frequency of absent response and asymmetric response was also noted. Mean heart rate under relaxed sitting condition was significantly higher in the study group. Significant negative correlation between heart rate and age was noted in the control group but was not present in the study group. Also, there was no statistical difference of mean RRIV between the two groups. No objective evidence of autonomic disturbance in patients with cerebral palsy was found in this study.