Quantifying spasticity in a clinical setting

Abstract

We describe a technique specifically designed for use in a clinical setting to quantify the spastic reflex response. Spasticity, which manifests as a hyperactive stretch reflex response, is the major component of cerebral palsy (CP) that interferes with normal function. Clinically, a patient's spasticity is monitored and subjectively graded by an examiner while moving the joint throughout its range of motion. Grading of the abnormal resistance is classified by clinical scales. The subjective clinical scales, however, tend to have poor inter-rater reliability and often poor correlation with functional improvements. Although objective measures of spasticity exist, their use has been limited to research laboratories, they have not been applied to the CP population, and their usefulness is determined by their correlation with subjective clinical measures. We describe a technique to quantify spasticity in a clinical setting. This technique, termed CATCH (Computer Assisted Technique to Characterize Hypertonia) integrates measurement of joint kinematics and muscle electromyography to quantify the spastic reflex response in CP. Three clinical cases are presented. These preliminary examples from the clinic suggest that this technique provides an improved method to monitor spasticity.