(171) Evaluating the Pain and Discomfort Scale to Assess Spasticity-Related Pain in Cerebral Palsy

Abstract

Assessing pain among individuals with communicative impairments and developmental disabilities is a clinical challenge. In this preliminary study, we addressed, in part, the issue of the association between chronic pain and spasticity in cerebral palsy (CP). Specifically, we evaluated the measurement performance of a proxy-reported spasticity rating scale (Multiple Sclerosis Spasticity Scale–MSSS) and the feasibility of a range of motion examination procedure (Pain Examination Procedure–PEP) using direct-observation to code behavioral reactivity during the exam (Pain and Discomfort Scale – PADS). Fifteen individuals with CP (mean age=10.9 years, range=6.2-17.2 years; GMFCS=3-5; male=46%) were evaluated pre- (T1) and post- (T2) intrathecal baclofen pump (ITB) surgical implant to treat spasticity. The PEP protocol was successfully completed for all participants in the clinical setting. Cronbach's alpha for the MSSS was 0.96. PADS change scores (T1 to T2) were significantly correlated with MSSS change scores (r=0.80, p=0.006). The strong positive correlation suggests the PADS/PEP protocol may be measuring spasticity-related pain and discomfort, providing initial construct validity evidence between an objective/direct and subjective/indirect assessment method for pain and spasticity in CP. T1 PADS scores were also highly positively correlated with both PADS change and MSSS change scores (r=-0.72, p=0.006; r=-0.85, p=0.002), providing preliminary evidence of the predictive utility of a pre-ITB surgery PADS/PEP protocol. This was not a random sample, therefore the results are specific to the sample and may not hold for the population of individuals living with CP. Given the absence of self-report, we cannot be certain and do not claim to have measured the pain experience of the individuals in the sample. Future work should continue to examine the PADS as a potential pain behavior assessment tool to provide a direct assessment option for the study of pain among individuals with CP and related developmental disabilities. Supported by NICHD Grant No. 73126