Abstracts

Rationale: We want to study the role of the primary motor cortex (PMC) in patients with vascular destructive lesions in perirolandic regions. Neuroplastic mechanisms operate and these patients have some motor functionality. This picture is more complex when occur seizures arousing from the scar and eventually when this area is resected. We report pre-and post-operative motor functional magnetic resonance (fMRI) findings in 12 patients with refractory epilepsy. Methods: Twelve patients with congenital hemiparesis underwent pre-surgical fMRI. All had cortical resections and were re-scanned 12 to 36 months after surgery. Activation maps were superimposed over anatomical images; analysis using Student t test with a P<0.0001. Limbs were evaluated with neurological exam in 12 to 36 months. Results: Pre-operatively, fMRI showed 3 main patterns. The first showed activation of PMC adjacent to the destructive lesion. The second was characterized by absence of activation of the PMC ipsilateral to the lesion; and activation in the normal hemisphere. A third displayed bilateral activation of PMC. Postoperatively, patients who did not have activation of the motor cortex adjacent to the lesion regained activation, and that was accompanied by improved motor function. Conclusions: These findings suggest that the PMC in the lesioned hemisphere may play a role in the motor function of the paretic limbs. Furthemore, the post-operative activation of previously silent PMC in some patients suggest that recurrent seizures and epileptogenic discharges may inhibit potentially preserved function. The improved motor function accompanied these positive fMRI changes adds credibility and raises the issue of new therapeutic.