Medial reorganization of motor function in corona radiata following middle cerebral artery infarction A case report

Peri-lesional reorganization is one of the motor recovery mechanisms following stroke. A 23-year-old female who presented with complete paralysis of the right extremities at the onset of infarct in the left middle cerebral artery territory was included. She slowly recovered some function, and could extend the affected knee with resistance after 9 months. Diffusion tensor tractography, functional MRI, and transcranial magnetic stimulation testing were performed at 7 years after onset. Results showed that diffusion tensor tractography of the affected （left） hemisphere passed through the medial corona radiata at, or around, the wall of the lateral ventricle. The contralateral primary sensorimotor cortex was activated during affected knee movements. The motor-evoked potential, which was obtained from the affected leg, exhibited corticospinal tract characteristics. Results indicated that motor function of the affected leg recovered via the corticospinal tract, which descended through the corona radiata medial to the infarct. The motor function of the affected leg was reorganized to the medial corona radiata following infarct to the middle cerebral artery territory.

Brain remodeling after chronic median nerve compression in a rat model

Carpal tunnel syndrome is the most common compressive neuropathy,presenting with sensorimotor dysfunction.In carpal tunnel syndrome patients,irregular afferent signals on functional magnetic resonance imaging are associated with changes in neural plasticity during peripheral nerve injury.However,it is difficult to obtain multi-point neuroimaging data of the brain in the clinic.In the present study,a rat model of median nerve compression was established by median nerve ligation,i.e.,carpal tunnel syndrome model.Sensory cortex remodeling was determined by functional magnetic resonance imaging between normal rats and carpal tunnel syndrome models at 2 weeks and 2 months after operation.Stimulation of bilateral paws by electricity for 30 seconds,alternating with 30 seconds of rest period（repeatedly 3 times）,resulted in activation of the contralateral sensorimotor cortex in normal rats.When carpal tunnel syndrome rats received this stimulation,the contralateral cerebral hemisphere was markedly activated at 2 weeks after operation,including the primary motor cortex,cerebellum,and thalamus.Moreover,this activation was not visible at 2 months after operation.These findings suggest that significant remodeling of the cerebral cortex appears at 2 weeks and 2 months after median nerve compression.

Novel role for transcranial magnetic stimulation to study post-traumatic respiratory neuroplasticity

Transcranial magnetic stimulation-a tool used in humans：Transcranial magnetic stimulation（TMS）is a non-invasive widespread clinical tool used to stimulate cortical areas in human subjects.This technique utilizes a brief,highly intense magnetic field applied to cortical areas,which locally depolarized interneurons（Weber and Eisen,2002）.

Resection of a dysembryoplastic neuroepithelial tumor in the precentral gyrus

Background:Dysembryoplastic neuroepithelial tumors(DNTs)are common causes of intractable epilepsy in pediatric epilepsy patients.The effect of surgical intervention is often limited when the tumor is located in the precentral gyrus.Furthermore,complete surgical resection is often not performed in order to avoid permanent neurological deficits.Methods:Here,we present a pediatric patient with intractable epilepsy caused by a simple DNT located in the precentral gyrus.Intracranial electrodes were implanted and used in combination with magnetic resonance imaging,video-electroencephalography and electrical cortical stimulation to assess neurological function,and where the epileptogenic zone was located.Results:The results of intracranial electrode monitoring suggested that the epileptogenic zone was located in the tumor area and that cortical function had been reorganized.We completely resected the tumor based on these findings.The patient has been seizure free after the surgery and has not had any neurological deficits.Conclusions:Simple form DNTs in the precentral gyrus can be completely resected with careful preoperative assessment of cortical function.Cortical reorganization could partly explain the functional preservation after surgery.