Abstracts

RATIONALE: Surgical treatment options for intractable seizures secondary to an epileptogenic focus located in the central sulcus region are limited. Described here is an alternative surgical approach for treating medically refractory non-lesional peri-rolandic epilepsy.
METHODS: We studied five consecutive patients with presumed non-lesional partial epilepsy of central lobule origin from 1996 to 2001. Preoperative assessment included prolonged video-scalp electroencephalography and single photon emission tomography (SPECT) scan co-registered with high-resolution MRI. Patients then underwent an awake stereotactic craniotomy guided by the EEG and SPECT/MRI studies, followed by cortical stimulation to identify the sensorimotor cortex and to reproduce the patient[ssquote]s aura. A subdural grid was then implanted based on these results. Subsequent post-operative recordings further delineated the site of seizure onset and functional cortex. During a second awake craniotomy, a limited resection of the central lobule region was performed. During the resection, neurological function was continuously monitored.
RESULTS: Five patients were 16 to 56 years old (mean = 28.6 years, four men and one woman). The duration of their epilepsy ranged from 8 to 39 (mean = 20.2) years with a mean frequency of 19 seizures per week. There were one limited resection in the precentral and two in the postcentral cortex. In two other cases, the excisions involved both the pre- and postcentral gyri. Histological examination revealed nonspecific gliosis in all five patients.
Postoperatively, three patients had a hemiparesis immediately following surgery. At follow-up, four recovered from their motor weakness, but one had persistent left upper extremity weakness. In four patients with the focus in the postcentral gyrus, the postoperative cortical sensory loss and apraxia resolved. Two patients were completely seizure free and two had non-disabling seizures (modified Engel Classification I). One patient had reduction in his seizure frequency (modified Engel Class IV). The follow-up period ranged from 6 months to five years (mean = 3.1 years).
CONCLUSIONS: An awake limited resection of the non-lesional epileptogenic sensorimotor cortex can be performed with acceptable neurological morbidity and may offer an alternative therapy to multiple subpial transection in the patients suffering from intractable epilepsy.