Sympathetic skin response and heart rate variability in patients with Huntington disease

Objective: To examine the autonomic nervous system functions in patients wi th Huntington disease. Background: Although patients with Huntington disease frequently experience vegetative symptoms, it is not clear if there is dysfunction of the autono mic nervous system. Methods: Sympathetic skin response (SSR) latency and amplitude from both pa lms and soles and R-R (heart rate) interval variation (RRIV) at rest and du ring the Valsalva maneuver were examined in 22 patients and 21 age-matched controls. Unified Huntington's Disease Rating Scale scores were determined in all the patients. Results: Our data are reported as means +/- SEMs. The SSR latencies in pati ents (mean palm latency, 1835.8 +/- 110.7 milliseconds; mean sole latency, 2625.3 +/- 226.9 milliseconds) were prolonged compared with controls (mean palm latency, 1359.5 +/- 28 milliseconds [P < .01]); mean sole latency, 203 8.1 +/- 44.9 milliseconds [P < .01]) and amplitudes in patients (moan ampli tude, 1063.1 +/- 237.7 mu V) were smaller compared with controls (mean ampl itude, 1846.3 +/- 251.2 mu V [P < .05]). The RRIV in patients both at rest (mean RRIV in patients, 3.7% +/- 0.4% vs controls, 9.7% +/- 0.6% [P < .01]) and during the Valsalva maneuver (mean RRIV in patients, 6.3% +/- 1.6% vs controls, 14.5% +/- 1.2% [P < .01]) was lower compared with controls. Furth ermore, the prolonged SR latencies, smaller amplitudes, and lower RRIV in p atients compared with controls closely correlated with the various componen ts of the Unified Huntington's Disease Rating Scale scores (total behavior score and SSR latency, R = 0.6 [P < .01]; total behavior score and SSR ampl itude, R = -0.5 [P < .05]; total behavior score and RRIV, R = -0.4 [P < .05 ]; verbal fluency and SSR latency, R = -0.5 [P < .05]; verbal fluency; and SSR amplitude, R = 0.5 [P < .05], verbal fluency and RRIV, R = 0.5 [P < .05 ], total functional capacity and SSR latency, R = -0.6 [P < .01]; total fun ctional capacity and SSR amplitude, R = 0.5 [P < .05]). Conclusion: These results suggest that there is autonomic nervous system dy sfunction in patients with Huntington disease.