ID 312 – Sensorimotor modulation by botulinum Toxin A in post-stroke arm spasticity: Passive hand movement

Abstract

Objective The aim of the study was to locate brain activation changes in stroke patients treated with Botulinum Toxin A (BoNT) for arm spasticity using functional MRI (fMRI). Methods Seven ischemic stroke patients (4 females, mean age 58.9) with severe spastic hand paralysis were studied. Spasticity was scored according to the modified Ashworth scale (MAS). FMRI was performed before (W0), 4 (W4) and 11 weeks (W11) after BoNT. Whole-brain fMRI data (1.5 T) were acquired during paced repetitive passive flexion/extension at the wrist of plegic limb alternating with rest. General Linear Model analysis used corrected cluster-wise p 0.05. Results BoNT transiently lowered MAS in W4. In all sessions, fMRI activation of the ipsilesional sensorimotor cortex (contralateral to the moved hand) dominated. At W4, bilateral cerebellum transiently engaged. Paired contrasts demonstrated significant differences W4 > W0 (bilateral cerebellum, occipital and prefrontal cortex) and W4 > W11 (ipsilesional cerebellum, contralesional thalamus, bilateral premotor and posterior cingulate cortex). Conclusions Whole-brain activation patterns during BoNT treatment of post-stroke arm spasticity demonstrated changes both within and outside the classical sensorimotor system. Specific BoNT-related changes were revealed in the cerebellum. Supported by IGA Ministry of Health Czech Republic Grant NT13575 .