Affiliations: Department of Neurorehabilitation, Kliniken Schmieder,
Allensbach, Germany
Note: [] Corresponding author: Prof. Dr. Joachim Liepert, Department of
Neurorehabilitation, Kliniken Schmieder, Zum Tafelholz 8, D-78476 Allensbach,
Germany. Tel.: +49 7533 808 1236; Fax: +49 7533 808 1441; E-mail:
j.liepert@kliniken-schmieder.de
Abstract: Background: Spasticity manifesting as a dysbalance between extensor
and flexor muscles may contribute to an impaired hand function. We studied
clinical (n=10 patients) and electrophysiological (n=9 patients) changes
produced by vibration of forearm extensor muscles (FEM) in chronic stroke
patients with spastic hemiparesis. Methods: In Exp. 1, the Box and Block
Test (BBT) was applied to test dexterity before and after 5 minutes of FEM
vibration. In Exp. 2, transcranial magnetic stimulation was used to study the
cortical silent period (CSP) before and during FEM vibration. Recordings were
taken from the antagonistic flexor carpi radialis muscle. Results: After vibration, performance of the BBT was improved by 20%. The effect persisted
for at least 10–15 minutes. Vibration induced a prolongation of the CSP. This
effect occurred in the affected and non-affected side to a similar degree. The
magnitude of performance changes and CSP changes was not correlated. Conclusions: FEM vibration enhances inhibitory neuronal circuits targeting the
antagonistic forearm flexor muscles and is associated with an improved
dexterity in the spastic arm. It might become a supporting tool in the motor
recovery of spastic hemiparesis.
