Functional outcome measures to assess interventions for spasticity

Clinicians use functional loss as a criterion to treat spasticity, but the connection between function and severity of spasticity is not well established for monitoring spasticity treatment effect. Studies were reviewed which have implemented outcome measures to assess functional changes relative to changes in spasticity. Criteria for review included the reliability and internal validity of the functional measures used and the strengths/weaknesses of the study designs that likely affected the external validity of the measures for this application. Guidelines are provided for the use and development of functional outcome measures in futures studies of spasticity treatment based on this review.

An English-language literature search using MEDLINE and bibliographies of published articles and textbooks was conducted.

Very few functional measures demonstrated changes concurrent to a reduction in spasticity. There were multiple potential confounding factors in study protocols, reporting of results, and data analysis that might account for the limited number of measures shown to be valid for this application. Selected standardized ordinal functional outcome scales (the PECS and PEDI) and specific functional tasks were identified as measures that show promise for assessing changes concurrent with altered spasticity level.

Based on a review of previous studies, functional measures involving posture, positioning, balance, and certain mobility skills have potential, with further test development, to provide needed information regarding the impact of spasticity on functional outcome.