Quantifying patterns of upper limb motor change following BTX-A injection in adult spasticity management

Abstract

Objective: To evaluate the capacity of the Upper Limb Performance Analysis: Comparative Analysis of Performance-Motor (CAP-M) to quantify change in adults with focal spasticity following injection of Botulinum Toxin-A (BTX-A) as a focal treatment for positive Upper Motor Neuron (UMN) features.

Methods: Twenty-three adults with moderate-to-severe spasticity were assessed pre- and post-BTX-A injection using CAP-M. Post-hoc video analysis of three sub-tests from the Action Research Arm Test were analysed against expected movements for each task.

Results: Post-injection, spasticity as measured by Modified Ashworth and Tardieu Composite scores decreased significantly (p < 0.001). Grouped CAP-M data showed a significant reduction (z = 2.1–2.7, ES = 0.51–0.56) in positive UMN features, with 145 fewer Excessive movements recorded. In addition, 31 more Expected movements were demonstrated (z = 2.9, ES = 0.60), consistent with ‘unmasking’ of movements.

Conclusion: CAP-M analysis revealed that BTX-A injection decreased unwanted movement almost 5-times more frequently than ‘unmasking’ hidden voluntary muscle activity during active simulated tasks. In this way, CAP-M was able to simultaneously assess positive and negative UMN features. This quantitative framework may have greater functional relevance than traditional uni-dimensional, passive spasticity measures such as MAS and Tardieu Scale.

• Adult
• Botulinum toxin A
• measurement
• spasticity
• upper limb

Declaration of interest

This paper is derived from data collected as part of an investigator initiated study supported by Ipsen Australia. H. Barden’s PhD candidature was supported by an Australian Postgraduate Award, The Helga Pettitt Faculty of Health Sciences Postgraduate Study Award 2011 and The George Burniston Cumberland Foundation Fellowship 2011. Honoraria received from Ipsen and Allergan (Barden, Baguley and Nott). Advisory Board membership for Ipsen (Baguley, Nott & Barden) and Allergan (Baguley & Nott). No declaration of Interest (Chapparo).