Effectiveness of BoNT A in Parkinson's Disease Upper Limb Tremor Management

Abstract

Abstract:Objective:One the greatest challenges of BoNT A therapy for tremor lies in the complexity and variation of components involved in tremor movement, and the lack of objective measures to determine these components. This 3 month open-label single injection study aims to couple clinician best judgment with kinematics to improve effect of BoNT A (incobotulinumtoxinA) injection in 7 patients with upper limb Parkinson's disease (PD) tremor.Methods:Injection was guided with clinical and kinematic assessment of tremor using angular wrist position in 3 degrees of freedom: flexion/extension, pronation/supination, and radial/ulnar deviation. Overall tremor severity and change were measured by linear finger acceleration.Results:Kinematic data from static and functional tasks demonstrate no improvement at one month post-injection, but significant improvement at two and three months. Clinical scales across UPDRS Items 20 (1, 2, 3 months post) and 21 (2 months), and spiral drawings (3 months) showed significant improvement from baseline, while line drawings did not.Conclusions:This study suggests injection of BoNT A as a viable focal management option for upper limb PD tremor. In addition to clinical judgment, objective quantification of tremor dynamics by kinematics may be a feasible assessment and guidance tool which can be used to optimize injection conditions for focal tremor therapy. Kinematic analysis of tremor across a variety of joints in all degrees of movement may provide important insight into tremor dynamics, allowing optimized, targeted focal therapy.

Long-term tremor therapy for Parkinson and essential tremor with sensor-guided botulinum toxin type A injections

“…This demonstrated the low agreement between clinical and objective assessments and highlighted the inherent difference between these assessment techniques. Samotus and colleagues and Rahimi and colleagues reported effect of BoNT-A for ET and PD tremor, respectively, following a 38-week treatment period and strongly suggested that the use of kinematic tremor analysis could continue to better tailor BoNT-A parameters to changes in each individual’s tremor [14–16]. By using kinematic data instead of visual assessment, physicians that are expert injectors but not experienced tremor assessors have a better chance in treating this disorder with ease using this systematic approach.…”

“…Tremor features were extracted from the angular signal data using custom-written software in MatLab ® (Version 2011a) [14–16]. For each participant, mean total tremor amplitude at each joint was displayed as angular root mean squared (RMS) amplitude degrees for each scripted task over three trials.…”

“…For each participant, mean total tremor amplitude at each joint was displayed as angular root mean squared (RMS) amplitude degrees for each scripted task over three trials. RMS units is a standard method of analyzing tremor severity and combining data from different degrees of freedom from the same origin [14–16]. Wrist and shoulder tremors detected during each task were further segmented into the amount of tremor present in each DOF that contributes to the overall total tremor at that joint, represented as a percentage.…”

“…Accelerometric sensors and validated rating scales can provide an overall arm tremor severity score but have not been reliably used for BoNT-A dosing. 12 Previously described by Rahimi and colleagues, multi-sensor kinematic technology is an effective technique for personalizing and optimizing BoNT-A therapy thereby ultimately reducing tremor amplitudes and improving quality of life (QoL) and clinical arm functionality in ET and PD patients [14–16]. By targeting muscles that contribute to overall tremor, the likelihood of muscle weakness in these patients was minimized over three serial treatments [14,15].…”

Therapeutic advances in tremor

“…No new controlled trials have specifically addressed PD tremor, but some open‐label observations provide interesting data for potential approaches. A 3‐month single‐injection study in seven patients suggested that botulinum toxin is effective for the management of upper limb PD‐related tremor, and another open‐label observational study in 22 patients with PD found a significant improvement of tremor 30 minutes after smoking cannabis …”