Surgery for epilepsy in the primary motor cortex: A critical review

Surgical resection of the epileptogenic zone within the frontal lobe can be a very effective treatment for medically refractory epilepsy originating from this area. While much of the frontal lobe consists of highly eloquent tissue, surgery is not necessarily contraindicated as long as the epileptogenic zone is well-localized and the tissue resected is limited. Resection of the primary motor cortex was described by Victor Horsley in the 19th century and was used frequently in the early 20th century for a variety of neurological disorders including epilepsy; improvements in surgical techniques and mapping has led to a resurgence of its use in the past few decades. Although many surgeons are hesitant to resect tissue adjacent to the primary hand area based on fears of new motor deficits, there is extensive evidence that focal resections are well-tolerated over the long-term with residual weakness that is fairly mild: some patients experience postoperative weakness, including hemiparesis, but a stereotypical recovery of strength from proximal to distal muscles occurs over months, and only one quarter will have a permanent neurologic deficit, usually consisting of difficulty with fine motor movements. The main alternative to surgical resection is subpial transection, characterized by a small decrease in postoperative deficits and significantly worse seizure outcomes. The treatment of patients with seizures originating from this region requires a solid understanding of the structural and functional anatomy of the frontal lobe.