Caloric vestibular stimulation for the management of motor and non-motor symptoms in Parkinson's disease

Introduction: A recent case study showed that repeated sessions of caloric vestibular stimulation (CVS) relieved motor and non-motor symptoms associated with Parkinson's disease (PD). Here we sought to confirm these results in a prospective, double-blind, randomized, placebo treatment-controlled study. Methods: 33 PD subjects receiving stable anti-Parkinsonian therapy completed an active (n = 16) or placebo (n = 17) treatment period. Subjects self-administered CVS at home twice-daily via a portable, pre-programmed, solid-state ThermoNeuroModulation (TNM (TM)) device, which delivered continually-varying thermal waveforms through aluminum ear-probes mounted on a wearable headset. Subjects were followed over a 4-week baseline period, 8 weeks of treatment and then at 5- and 24-weeks post-treatment. At each study visit, standardized clinical assessments were conducted during ON-medication states to evaluate changes in motor and non-motor symptoms, activities of daily living, and quality of life ratings. Results: Change scores between baseline and the end of treatment showed that active-arm subjects demonstrated clinically-relevant reductions in motor and non-motor symptoms that were significantly greater than placeboarm subjects. Active treatment was also associated with improved scores on activities of daily living assessments. Therapeutic gains were still evident 5 weeks after the end of active treatment but had started to recede at 24 weeks follow-up. No serious adverse events were associated with device use, and there was high participant satisfaction and tolerability of treatment. Conclusion: The results provide evidence that repeated CVS can provide safe and enduring adjuvant relief for motor and non-motor symptoms associated with PD.