Quantitative measurement of poststroke spasticity and response to treatment with botulinum toxin: a 2-patient case report.

BACKGROUND AND PURPOSE Spasticity (hypertonicity) is a frequent problem that can develop after stroke and can lead to a number of secondary complications, such as contractures and pain. Consequently, many rehabilitation resources are used in treating the condition and its secondary complications. At present, the clinical assessment of spasticity incorporates descriptive scales of resistance to passive movement, but the use of a neurophysiological measure of muscle activity levels has been advocated. This case report focuses on the diagnosis of spasticity through the use of a neurophysiological measure. CASE DESCRIPTION . Two individuals who required botulinum toxin treatment for poststroke spasticity were assessed over a course of 20 weeks with both clinical (Modified Ashworth Scale) and neurophysiological (surface electromyography recording of levels of muscle activity) measures of spasticity. Additionally, arm function, arm movement, and pain were measured. The individuals' responses to treatment with botulinum toxin and overall recovery after stroke are described. OUTCOMES There were discrepancies between the clinical and the neurophysiological measures of spasticity. The clinical measure of spasticity was not effective in consistently identifying the presence of spasticity and, therefore, also was ineffective in documenting the individuals' responses to treatment. The neurophysiological measure was able to identify when muscle activity levels had been reduced, but a reduction in muscle activity levels did not always correspond with a reduction in Modified Ashworth Scale scores. DISCUSSION The accurate identification of spasticity is important not only for assessment but also for the selection of appropriate treatments after stroke.