Nonlesional Focal Epilepsy

Finding the seizure focus or starting point and removing it
surgically (resection) can be challenging in patients with normal MRI scans. Nonlesional temporal lobe epilepsy is more easily localized and successfully treated than are nonlesional seizures that originate elsewhere in the brain. Most patients with nonlesional epilepsy outside of the temporal lobe, have frontal lobe epilepsy; many of the areas of the brain are silent and early clinical symptoms result from the electrical spread from the seizure-inducing area.  Also, these areas often overlap with functional areas, and thereby limit the size of the resection.  Despite the obvious limitations mentioned, there are a few epilepsy syndromes within the nonlesional frontal lobe epilepsies that can be recognized and might have good surgical outcomes.  One of these is the supplementary motor area epilepsy, in which a very particular pattern is observed.  Seizure-free rates after surgery range from 50% to 75% for this condition, compared with rates in the range of 35% to 50% for other frontal lobe epilepsies.