Effectiveness of Botox on Reducing Rest Tremor in Parkinson's Disease
Condition: Parkinson Disease
MeSH terms: Parkinson Disease; Tremor
Study type: Interventional
Phase: Phase 2

Summary: 
      Purpose: Rest tremor in Parkinson's disease is notoriously difficult to treat through
      pharmacological measures, currently only predictably attenuated by the invasive deep brain
      stimulation surgery. The investigators hope to find some predictable and clinically
      meaningful attenuation of tremor with targeted use of onabotulinum toxin on muscles involved
      in creating the tremor.

      Participants: 16 subjects who meet United Kingdom (UK) brain bank criteria for Parkinson's
      disease with medically refractory rest tremor of at least 3 cm amplitude.

      Procedures (methods): Subjects will be blinded to receive either sham saline injection versus
      onabotulinum toxin injections directed to muscle groups felt to be clinically involved in
      causing the oscillatory movement of the tremor. Assessment of tremor severity and functional
      improvement from baseline after injection will occur within group (i.e. each subject will
      serve as their own control).

      Hypotheses:

      1. (A) Onabotulinumtoxin A significantly attenuates the amplitude of medically-refractory
      rest tremor of the upper limb in Parkinson's patients as compared to sham injections; as
      measured by reduction in the Movement Disorders Society Unified Parkinson's Disease Rating
      Scale (MDS-UPDRS) tremor subscore.

      1. (B) Onabotulinumtoxin A significantly improves the limb function of Parkinson's patients
      with medically-refractory rest tremor of the upper limb as compared to sham injections; as
      measured by an increase in Action Research Arm Test (ARAT) scores.
    

Detailed description: 
      For purposes of properly identifying muscles intended for injection, a portable
      electromyography will be attached to an appropriate gauge electromyography-guided botulinum
      toxin needle, which in turn will be used to hear/see motor evoked potentials (MEPs). Subjects
      will be asked to activate the muscle while needle is inserted to ensure proper placement of
      the needle in the desired muscle prior to injection of study solution.
    

Intervention name(s): Onabotulinumtoxin A Injection; Placebo
Intervention type(s): Drug; Other
Intervention description(s): Reconstituted 10 units/0.1 mL. Administered intramuscular once; 0.9% normal saline solution, mimicking Botox injection paradigm. Administered intramuscular once.
Other intervention name(s): Botox; Normal saline
Intervention MeSH terms: Botulinum Toxins, Type A; abobotulinumtoxinA
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: The study will comprise of a double blinded, crossover study where the subjects will serve as their own controls. There will be no medication changes made to Parkinson's disease medications throughout the subjects' participation in the study.
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Treatment
Keywords: Parkinson, Botox, Tremor