Spasticity in the Upper Motor Neuron Syndrome: Measuring Upper Limb Performance following Acquired Brain Injury

Abstract

Difficulties exist with measuring functional upper limb (UL) change following Botulinum Toxin-A (BTX-A) injections for muscle spasticity in adults with acquired brain injury (ABI). These may result from limitations of clinical measures including psychometric properties and clinical relevance. Further, the complex nature of the upper motor neuron syndrome with the interplay of positive and negative features requires improved measures which evaluate both features simultaneously, such as emerging UL measures: Dynamic Computerised hand Dynamometry (DCD) and the Upper Limb Performance Analysis (ULPA). This research focused on the investigation of the psychometric properties and the capacity to quantify change in UL performance following BTX-A injection of DCD and the ULPA. A multicentre study design with longitudinal data collection over three time points was used to measure UL performance of 40 community dwelling adults with UL spasticity resulting from ABI and 27 healthy controls. Participants with ABI were consecutively recruited from three metropolitan spasticity management clinics. The research protocol consisted of a selection of UL performance measures spanning the ICF domains of Body Function and Structure and Activity. Results from this research demonstrate fair to excellent test-retest reliability and fair to good construct, concurrent and predictive validity of DCD. DCD was able to identify clear differences in hand performance between participants with and without ABI, and the affected and non-affected hands of ABI participants. Good construct and concurrent validity was demonstrated for the ULPA. Finally, significant change in UL performance was demonstrated using both DCD and the ULPA. This research has demonstrated the psychometric properties and clinical relevance of DCD and the ULPA. These measures may be used to measure treatment efficacy and assist clinical decision making for other UL interventions for adults with UMN syndrome resulting from ABI.