Mechanical somatosensory stimulation decreases blood pressure in patients with Parkinson's disease

Objective: The current study aimed to assess the effects of five cycles of automated mechanical somatosensory stimulation (AMSS) of the fore-feet on blood pressure (BP) and cardiovascular autonomic control in Parkinson's Disease patients. Methods: Out of 23 patients, 16 underwent an AMSS session every 72 h, for a total of five sessions per patient. Electrocardiogram, noninvasive beat-to-beat blood pressure and respiratory activity were recorded for 20 min in supine position at baseline and after the AMSS sessions. Main outcomes were the changes in SBP and DBP, in the spectral indices of cardiac sympathetic (LFRR n.u.) and vagal (HFRR) modulatory activities, cardiac sympathovagal relationship (LF/HF), vascular sympathetic modulation (LFSAP) and arterial baroreflex sensitivity (sequence technique). Symbolic analysis of heart rate variability provided additional indices of cardiac sympathetic (OV%) and vagal (2UV%) modulation to the sinoatrial node. Results: After five AMSS trials a reduction in SBP (baseline: 131.2 +/- 15.5 mmHg; post-AMSS: 122.4 +/- 16.2 mmHg; P = 0.0004) and DBP (baseline: 73.2 +/- 6.1 mmHg; post-AMSS: 68.9 +/- 6.2 mmHg; P = 0.008) was observed. Post-AMSS, spectral and symbolic indices of cardiovascular sympathetic control decreased and arterial baroreflex sensitivity increased (baseline: 5.7 +/- 1.3 ms/mmHg; post-AMSS: 11.27 +/- 2.7 ms/mmHg). Conclusion: AMSS sessions were effective in reducing BP, increasing baroreflex sensitivity and decreasing cardiovascular sympathetic modulation in Parkinson's disease patients. AMSS might be useful to control supine hypertension in Parkinson's disease.