Fariborz Rahimi1, Derek Debicki2, Angela Roberts-South3, Carina Bee1, Priya Bapat4, Mandar Jog1. 1. 1London Health Sciences Centre,Western University,London,ON,Canada. 2. 2Department of Neurology,Western University,London,ON,Canada. 3. 3Department of Health Rehabilitation Sciences,Western University,London,ON,Canada. 4. 4Department of Physiology and Pharmacology,Western University,London,ON,Canada.
Abstract
BACKGROUND: Treatment options for essential (ET) and Parkinson disease (PD) tremor are suboptimal, with significant side effects. Botulinum toxin type A (BoNT A) is successfully used in management of various focal movement disorders but is not widely used for tremor. METHOD: This study examines complexity of wrist tremor in terms of involvement of its three anatomical degrees of freedom (DOF) in two common situations of rest and posture. The study examines tremor in 11 ET and 17 PD participants by kinematic decomposition of motion in 3-DOF. RESULTS: Tremor decomposition showed the motion involved more than one DOF (<70% contribution in one DOF) in most ET (rest: 100%, posture: 64%) and PD (rest: 77%, posture: 77%) patients. Task variation resulted in change in both amplitude and composition in ET, but not in PD. Amplitude significantly increased from rest to posture in ET. Directional bias was observed at the wrist for ET (pronation), and PD (extension, ulnar deviation, pronation). Average agreement between clinical visual and kinematic selection of muscles was 55% across all subjects. CONCLUSION: This study shows the complexity of tremor and the difficulty in visual judgment of tremor, which may be key to the success of targeted focal treatments such as BoNT A.
BACKGROUND: Treatment options for essential (ET) and Parkinson disease (PD) tremor are suboptimal, with significant side effects. Botulinum toxin type A (BoNT A) is successfully used in management of various focal movement disorders but is not widely used for tremor. METHOD: This study examines complexity of wrist tremor in terms of involvement of its three anatomical degrees of freedom (DOF) in two common situations of rest and posture. The study examines tremor in 11 ET and 17 PDparticipants by kinematic decomposition of motion in 3-DOF. RESULTS:Tremor decomposition showed the motion involved more than one DOF (<70% contribution in one DOF) in most ET (rest: 100%, posture: 64%) and PD (rest: 77%, posture: 77%) patients. Task variation resulted in change in both amplitude and composition in ET, but not in PD. Amplitude significantly increased from rest to posture in ET. Directional bias was observed at the wrist for ET (pronation), and PD (extension, ulnar deviation, pronation). Average agreement between clinical visual and kinematic selection of muscles was 55% across all subjects. CONCLUSION: This study shows the complexity of tremor and the difficulty in visual judgment of tremor, which may be key to the success of targeted focal treatments such as BoNT A.
Authors: Adam C Pigg; Johanna Thompson-Westra; Karin Mente; Carine W Maurer; Dietrich Haubenberger; Mark Hallett; Steven K Charles Journal: Clin Neurophysiol Date: 2020-09-02 Impact factor: 3.708