Non-invasive intervention for motor signs of Parkinson's disease: the effect of vibratory stimuli.

In recent years there has been a renewed interest in the use of peripheral vibration to ameliorate some of the motor symptoms of Parkinson’s disease (PD). The possibility that peripheral vibration can improve patients’ motor symptoms is exciting as the intervention is non-invasive and of low cost. However, there remains little published scientific research to support some of the claims. Previously we demonstrated that vibration at 80 Hz at the wrist for 30 s prior to movement onset improved motor performance in a variety of manual tasks both in healthy controls and in patients with PD.1 Here we report the results of testing whether a wearable haptic device (the ‘Emma Watch’) developed by Microsoft Research,2 which delivers constant vibratory stimuli at the wrist, significantly improves motor function of the stimulated upper limb in patients with PD. The Emma Watch delivers constant vibration at 200 Hz through six small electromagnetic mechanical stimulators, three on each side of the wrist. The vibration frequency is modulated by a lower frequency, either 20 bpm (beats per minute) or 60 bpm. These modulation parameters were based on the parameter that improved motor function in the first tested patient with PD (60 bpm) and on a parameter that did not (20 bpm). Here we tested whether the Emma Watch could improve motor function in 16 patients with PD (11 women, mean age=63 years, range 52–72 years, Unified Parkinson’s …