Reliability of clinical spasticity measurements in patients with cervical spinal cord injury.

BACKGROUND The Modified Ashworth Scale (MAS) is the most popular clinical measure of spasticity. Other clinical signs of spasticity include hyperactive tendon reflexes, myoclonus and Babinski sign. PURPOSE To assess reliability of the MAS with myoclonic and tendon reflex examination (MTR) in patients with spinal cord injury (SCI). MATERIAL AND METHODS 30 patients (16 with complete and 14 with incomplete neural deficit) who sustained cervical SCI 4-66 months prior to the study. Mean age 33,9 years (SD=14,7). 6 independent observers rated MAS and MTR in each patient. RESULTS Poor interrater reliability of MAS (ICC=0.56) and good reliability of MTR (ICC=0.81) were demonstrated. There was satisfactory to good correlation between averaged MAS rates (Pearson coefficient 0.67-0.9). MAS reliability was lower in the lower limbs and when joint contractures were present. Significantly (p<0.01) lower MAS repeatability was noted in subjects below 30 years of age. There was a positive correlation between patient functional status and MAS repeatability. MAS reliability did not depend on mean muscle tone, sex, or time since injury. CONCLUSIONS Although MAS does not reliably assess the tone of individual muscle groups in patients with SCI, it may be helpful in assessing overall muscular tone. MAS repeatability is lower in younger patients. MAS is inappropriate for the assessment of patients with joint contractures. An examination of tendon reflexes, myoclonus and the Babinski sign is reliable in SCI patients