Electrophysiological Demonstration of Motor Reorganization in Healthy Hemispheres of Patients with Intractable Epilepsy due to Early Unilateral Brain Damage

Abstract Background: The functional reorganization of motor functions is a sign of adaptive brain plasticity to brain damage and understanding its mechanisms may be a key role to many treatment models for brain damage in childhood and even in adults. Our aim is to show an electrophysiological evidence of brain plasticity regarding motor functions in early brain damaged patients. Methods: We retrospectively analyzed four patients with some extremity motor functions shifting to unusual brain areas who were diagnosed with childhood epilepsy and underwent epilepsy surgery. We analyzed their clinical and surgical data particularly including intraoperative neuromonitorization (IONM) results. Results: Patients’ preoperative data showed some motor representation of extremities was located somewhere else than the expected brain areas due to perinatal damage. In first patient right hand presentation was shifted to the right hemisphere and in second patient right hand was represented on both hemispheres. In the remaining two patients, all the motor functions of epileptogenic hemisphere were shifted to the contralateral side. IONM proved the neuroplasticity of the patients with previously crossed motor functions and was in line with preoperative functional Magnetic Resonance Imaging data. Conclusion: Brain plasticity can alter the motor reorganization of the healthy hemisphere by taking upon the functions of the pathological hemisphere.