The Effect of Vibrotactile Stimulation on Parkinson's Tremor
Condition: Parkinson Disease; Tremor
MeSH terms: Parkinson Disease; Tremor
Study type: Interventional

Summary: 
      Tremor in Parkinson's disease is a common and highly burdensome symptom. Recent evidence
      shows that areas in the brain that are underlying Parkinson's tremor overlap with those that
      respond to somatosensory stimulation. Applying such stimulation to the tremulous limb might
      therefore influence tremor-related brain activity and thereby potentially reduce tremor. In
      this study, the investigators explore this possibility and investigate whether tremor
      specific vibrotactile stimulation at the wrist of the most affected arm influences tremor
      severity.
    

Detailed description: 
      Parkinson's disease (PD) is the second most common neurodegenerative disease, of which tremor
      is a common and highly burdensome symptom. The pathophysiology of tremor involves a cerebral
      network that consists of basal ganglia and a cerebello-thalamo-cortical motor circuit.
      Emerging evidence suggests that somatosensory input from the tremulous limb to the brain may
      influence this network. Specifically, tremor-related activity was observed in primary and
      secondary somatosensory cortex, and thalamic cells involved in tremor appear to be responsive
      to somatosensory stimulation as well. Somatosensory afferents may thus play a role in tremor
      pathophysiology and could therefore be used as treatment target. Here, the investigators will
      test this hypothesis by investigating the effect of modulating somatosensory input (with
      vibrotactile stimulation) on tremor severity.

      The primary objectives are 1) to test whether rhythmic somatosensory input (vibrotactile
      stimulation) at tremor frequency reduces tremor power of Parkinson's tremor as compared to
      vibrotactile stimulation at 1.5 times tremor frequency and 2) whether continuous 80Hz
      vibrotactile stimulation reduces tremor power as compared to sham stimulation. As secondary
      objectives, the investigators will test whether the effect of vibrotactile stimulation on
      tremor power depends on the context in which tremor occurs (rest, cognitive coactivation,
      posture), whether stimulation at tremor frequency reduces tremor power as compared to sham
      stimulation, and whether vibrotactile stimulation has an effect on two other common PD
      symptoms: impaired gait and bradykinesia. The investigators will include 27 patients with
      Parkinson's disease and rest as well as postural tremor. The intervention involves subtle
      mechanical vibrations on the wrist or ankles. This is a non-invasive and painless way to
      provide somatosensory stimuli, in a continuous (80Hz) or rhythmic fashion (brief bursts of 80
      Hz at tremor or step frequency).

      The investigators expect that this study will provide mechanistic insights into if and how
      somatosensory (vibro-tactile) afferents influence the cerebral tremor circuit in Parkinson's
      disease, and may provide a solid basis for designing further clinical treatment studies.
    

Intervention name(s): Vibrotactile stimulation at tremor frequency; Vibrotactile stimulation at tremor frequency*1.5; Vibrotactile stimulation at continuous stimulation; Vibrotactile stimulation 10% below and above step frequency
Intervention type(s): Device; Device; Device; Device
Intervention description(s): Mechanical vibrations are applied at brief bursts of 80Hz that occur at the individual tremor frequency. Vibrations are delivered via a small device, which is worn on the wrist of the most-affected arm.; Mechanical vibrations are applied at 80Hz bursts at individual tremor frequency*1.5. Vibrations are delivered via a small device, which is worn on the wrist of the most-affected arm.; Continuous 80Hz stimulation is applied via a small device worn on the wrist of the most-affected arm.; This intervention is applied during assessment of gait. Two devices are worn on both ankles which allows alternating stimulation of both ankles with brief bursts of 80 HZ at the individual step frequency plus or minus 10%.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Parkinson disease; Vibrotactile stimulation; Tremor