The Effectiveness of 1Hz rTMS Over the Primary Motor Area of the Unaffected Hemisphere to Improve Hand Function After Stroke Depends on Hemispheric Dominance

Objective: Inhibition of motor cortex excitability of the contralesional hemisphere may improve dexterity of the affected hand after stroke. Methods: 40 patients (17 dominant hemispheric stroke, 23 non-dominant hemispheric stroke) with a mild to moderate upper limb motor impairment were enrolled in a double-blind, randomized, placebo-controlled trial with two parallel-groups. Both groups received 15 daily sessions of motor training preceded by either 1Hz rTMS or sham rTMS. Behavioral and neurophysiological evaluations were performed at baseline, after the first week and after the third week of treatment, and after a 6 months follow-up. Results: In both groups motor function of the affected hand improved significantly. Patients with stroke of the non-dominant hemisphere made a similar improvement, regardless of whether the motor training was preceded by sham or 1Hz rTMS. Patients with stroke of the dominant hemisphere had a less favorable improvement than those with stroke of the non-dominant hemisphere after motor training preceded by sham rTMS. However, when 1Hz rTMS preceded the motor training, patients with stroke of the dominant hemisphere made a similar improvement as those with stroke of the non-dominant hemisphere. Interpretation: Motor recovery of the affected upper limb after stroke is determined by dominance of the affected hemisphere. Stroke of the dominant hemisphere is associated with per se poorer improvement of the affected hand. 1Hz rTMS over the contralesional M1 significantly improves dexterity of the affected hand in patients with stroke of the dominant hemisphere, but not in those with stroke of the non-dominant hemisphere. (C) 2015 Elsevier Inc. All rights reserved.