Decreased short-interval intracortical inhibition correlates with better pinch strength in patients with stroke and good motor recovery

Abstract

BackgroundDeeper short-interval intracortical inhibition (SICI), a marker of GABAA activity, correlates with better motor performance in patients with moderate to severe hand impairments in the chronic phase after stroke. ObjectivesWe evaluated the correlation between SICI in the affected hemisphere and pinch force of the paretic hand in well-recovered patients. We also investigated the correlation between SICI and pinch force in controls. MethodsTwenty-two subjects were included in the study. SICI was measured with a paired-pulse paradigm. The correlation between lateral pinch strength and SICI was assessed with Spearman's rho. ResultsThere was a significant correlation (rho = 0.69, p = 0.014) between SICI and pinch strength in patients, but not in controls. SICI was significantly deeper in patients with greater hand weakness. ConclusionsThese preliminary findings suggest that decreased GABAA activity in M1AH correlates with better hand motor performance in well-recovered subjects with stroke in the chronic phase.