Heart rate variability in Parkinson's disease unaffected by deep brain stimulation.

Trachani E, Constantoyannis C, Sakellaropoulos GC, Stavrinou ML, Nikiforidis G, Chroni E. Heart rate variability in Parkinson’s disease unaffected by deep brain stimulation. Acta Neurol Scand: 2012: 126: 56–61. © 2011 John Wiley & Sons A/S. Objectives –  Our aim was to investigate the impact of subthalamic nucleus deep brain stimulation (STN-DBS) on the cardiovagal control of patients with advanced Parkinson’s disease. Materials and methods –  Twenty-four patients (mean age: 62.1 ± 9.4 years) were examined 3 days before and 6 months after DBS by a questionnaire, blood pressure monitoring and a battery of neurophysiological tests: time domain analysis of RR interval variation during normal and deep breathing (DB), Valsalva manoeuvre, and tilt test. By off-line, performed frequency domain analysis of heart rate variation, total power (TP), low frequency band (LF) band, high-frequency (HF) band, and their normalized units were estimated. The neurophysiological measurements were compared to those of 24 healthy controls. Results –  The values of time domain variables were pre- and postoperatively lower in patients than in controls. A significant reduction was found in LF band after the implantation. Orthostatic hypotension was present in 45.8% of the patients preoperatively and 12.5% postoperatively. There was no correlation between DBS-related changes of motor function and corresponding neurophysiological measurements, but patients with more than 60% motor improvement had higher time domain parameters’ values than the others. Conclusions –  STN-DBS offered no considerable impact on autonomic cardiovascular control.