The Relationship between Cutaneous Silent Period and Spasticity in Patients with Stroke

J Korean Assoc EMG Electrodiagn Med 2008;10(1):1-5.
Published online June 1, 2008.

Abstract

Objectives: The cutaneous silent period (CSP) is a spinal inhibitory reflex related to the stimulation ofslow-conducting A-δ fibers. The aim of this study is to evaluate the relationship between spasticity andCSP in patients with stroke.Methods: Twelve stroke patients with hemiplegia were enrolled in the study. The CSP was recordedfrom the thenar muscles during voluntary contraction. A stimulation train consisting of five noxious electricalshocks was applied to ipsilateral digit II cutaneous nerve to record the CSP. Modified Ashworthscale (MAS) was assessed by an experienced physician.Results: The means of CSP durations were 83.08±18.26 ms and 56.50±9.74 ms on the affected side andthe sound side respectively. The CSP duration on the affected side was significantly longer than that ofthe sound side (p<0.05). The difference of CSP duration between sound side and affected side did notcorrelate well with the MAS.Conclusion: Our findings showed that the CSP duration on the affected side was longer than that of thesound side and did not correlate well with the MAS. The CSP may be one of the useful tools to evaluatecentral nervous system. Further study will be needed to find out correlation between the CSP and thespasticity.

Key Words: Cutaneous silent period, Spasticity, Stroke