From where to how: assessing mechanisms of neural plasticity in patients with unilateral brain lesions

A set of different algorithms was involved to analyze the anomalous motor control in four young hemi-paretic patients with pre-and perinatally acquired brain lesions. The effects of a peculiar cerebral reorganization allow the patients to move the paretic arm. Patients performed a pinch grip using their paretic and non-paretic hands alternatively. EMG was simultaneously recorded as a basis for coherence calculations. 3D coherence mapping was performed in the beta frequency range. Such approach evidenced the relocation of motor functions from the lesioned (left) to the contralesional (right) hemisphere. While in case of left, non-paretic pinch grip, coherent activity originated from contralateral (right) Ml exclusively, right (paretic) grip, produced coherent activity in ipsilateral Ml as well as significant coherence of ipsilateral cerebellum. Coupling direction analysis demonstrated that throughout pinch grip the coupling direction goes from Ml to cerebellum.