Clinical assessment of spasticity in spinal cord injury: A multidimensional problem

Objective: To determine the relation between various components of spasticity evaluated clinically in persons with spinal cord injury (SCI). Design: Case series evaluating spasticity using clinical scales commonly referenced in contemporary literature, including the Penn Spasm Frequency Scale, the Ashworth Scale, and standard scales of tendon taps, clonus, and plantar stimulation. Setting: A Veterans Affairs Medical Center Spinal Cord Injury Center. Patients: Eighty-five spinal cord injured individuals with varying degrees of spasticity. Results: Correlations demonstrated weak relationships between Spasm Frequency Scale and self-report scales of interference with function (.407) and painful spasms (.312). No clinical examination score correlated with self-report scores greater than 0.4. Three clinical examination scores correlated modestly (>0.5)-Ashworth score with patellar tendon taps (.553), ankle clonus with Achilles tendon tap (.663), and patellar tendon tap with adductor tendon tap (.512). Two other clinical scales correlated weakly (>0.4)-Achilles tendon tap with patellar tendon tap (.417) and plantar reflex with adductor tendon taps (.423). Conclusions: Clinical scales currently used to evaluate spasticity in SCI correlate poorly with each other, suggesting that they each assess different aspects of spasticity. The use of any single scale is likely to underrepresent the magnitude and severity of spasticity in the SCI population. In the absence of agreement among these various scales and with the absence of an appropriate criterion standard for evaluation of spasticity, assessments of spasticity, whether clinical or neurophysiological in nature, should be comprehensive in scope.