ID 30 – Influence of M1 hand knob ischemic stroke on motor activation: An fMRI study in chronic stage

Abstract

Objective To evaluate whether stroke lesion focused on the primary motor cortex hand knob re-localizes the hand motor area in the affected hemisphere. Methods The study included 8 right-handed chronic ischemic stroke patients (2 females, age range: 48–68 years) with hand knob localized lesion (2 left hemisphere, 6 right hemisphere, at least 2 years from stroke). Block-design fMRI was performed using a 3T MR scanner during finger tapping task to both hemispheres. For the analysis, images with left hemisphere lesions were flipped. Differences between affected and unaffected hemispheres were tested with a paired t-test using a threshold of p T = 4.79), uncorrected for multiple comparisons. Results Significantly reduced motor activation in the affected hemisphere versus unaffected hemisphere was observed in the posterior part of precentral gyrus (hand-knob), pars opercularis and pars triangularis of the inferior frontal gyrus, inferior parietal cortex, intraparietal sulcus and lobule VI in cerebellum. Conclusions Reduction in the hand motor activation was observed in M1 in the affected hemisphere. Key message fMRI is capable to detect abnormal motor activation after focal stroke on hand knob area.