Resection of the epileptogenic area in critical cortex with the aid of a subdural electrode grid.
Electrode grids were implanted subdurally in 28 patients with epilepsy. In 16 of the 28 patients, an epileptogenic area was located in the speech-dominant left temporal lobe. Recordings made with the grid revealed that the epileptogenic areas in the patients varied widely in extent: the area was confined within the first 10 mm of the temporal lobe in some patients or it was scattered throughout the entire anterior to posterior 80-mm extend in others. Resection of the epileptogenic area was adjusted accordingly in each case. In 6 of 16 patients who were left-hemisphere-dominant for language, up to 55-80 mm from the tip of the temporal lobe was removed, a measure that exceeds the conventional limit of 50 mm from the tip of the dominant hemisphere. In the remaining 12 of the 28 patients, epileptogenic areas were located in a combination of several lobes. In 7 of these 12 patients, the epileptogenic area encompassed the rolandic area; it was removed without deficit in 4 patients and with expected deficit in 3. Of the latter 3 patients, 1 patient underwent hemispherectomy, and a large portion of the epileptogenic rolandic cortex in the frontal and parietal lobes was removed from the other 2. There were 2 cases of grid-related infection, which cleared with antibiotic treatment; there were no lasting complications of grid implantation in any patient. There was no mortality. Electroencephalographic recording and functional mapping using subdural electrode grids allow a tailored, maximal resection of epileptogenic tissue with minimal injury to critical cortex.
Uematsu
S
S
Johns Hopkins Epilepsy Center, Department of Neurosurgery, Baltimore, Md.
Lesser
R
R
Fisher
R
R
Krauss
G
G
Hart
J
J
Vining
E P
EP
Freeman
J
J
Gordon
B
B
D001927:Brain Diseases / Q000503:physiopathology / Q000601:surgery; D001931:Brain Mapping / Q000295:instrumentation*; D001932:Brain Neoplasms / Q000503:physiopathology / Q000601:surgery; D002540:Cerebral Cortex / Q000503:physiopathology / Q000601:surgery*; D003196:Computer Graphics; D003560:Cysts / Q000503:physiopathology / Q000601:surgery; D004292:Dominance, Cerebral / Q000502:physiology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation*; D004827:Epilepsy / Q000503:physiopathology / Q000601:surgery*; D006624:Hippocampus / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D011612:Psychosurgery; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013060:Speech / Q000502:physiology*; D013238:Stereotaxic Techniques / Q000295:instrumentation*; D013702:Temporal Lobe / Q000503:physiopathology / Q000601:surgery