Abstracts

Rationale: Corpus callosotomy (CC) is a surgical disconnection to treat generalized and atonic seizures in refractory epilepsy patients. Traditional open surgery is associated with risks of craniotomy and prolonged recovery. While minimally invasive MRI-guided stereotactic laser ablation is a safe, effective, and well-tolerated alternative for refractory focal epilepsy, stereotactic laser corpus callosotomy (SLCC) is less defined. Methods: Between 2007 and 2015, 4 adults with refractory epilepsy underwent traditional open CC and 4 underwent SLCC at our epilepsy center. Demographic information, seizure and EEG data, surgical procedure performed, duration of hospitalization, postoperative complications, and seizure outcomes were collected and compared. Results: At time of surgery, patients in the SLCC and open CC groups were a median 32.5 (range 20-47) and 32 (range 26-39) y of age, respectively, and had had seizures for 30 (range 10-42) and 25 (range 20-27) y, respectively. All but 1 SLCC patient had prior vagus nerve stimulation, 1 subject in each group had prior temporal lobe surgery, and all but one CC subject was male. All 4 SLCC patients had atonic seizures and EEG features of Lennox Gastaut syndrome (LGS); 3 underwent anterior 2/3 SLCC; of which 1 underwent additional ablation (posterior 1/3 SLCC) 1 m later for continued seizures. A 4th SLCC patient that had remote incomplete open CC developed worse atonic seizures after mesial temporal ablation (stereotactic laser amygdalohippocampotomy) for sclerosis, and he underwent completion SLCC (genu and splenium) 8 m later. In the open CC group, 2 pts had refractory focal seizures with generalization; 2 had LGS with atonic seizures; all underwent anterior 2/3 CC. The acute hospitalizations in the SLCC and open CC groups were median 3.5 (range 2-9) and 13 (range 3-21) d, respectively. This increased to 11 (range 2-31) d and 21 (range 10-35) d, respectively, when subsequent inpatient rehab admissions and an early readmission in 1 CC patient for seizures were included. One patient in each group had an intracranial hemorrhage, and 1 patient in each group had supplementary motor area syndrome. Two SLCC patients had persistent deficits (mild hemiparesis; incontinence); 1 CC patient had persistent abulia. With median postoperative follow-up of 9 m (range 6-16 m) and 5 y (range 9 m?"9 y), atonic seizures ceased in all SLCC and 1 of 2 CC patients, respectively. Generalized seizures decreased by >50% in all patients except 1 SLCC patient. All SLCC patients had either cessation or >50% decrease in absence seizures. Absence and focal seizures were unchanged in 3 of 4 CC patients. Whereas 2 SLCC patients were completely seizure free, none of the open CC patients were completely seizure free. Conclusions: In this preliminary study, minimally invasive MRI guided SLCC is a safe and effective alternative to traditional open CC. Patients undergoing SLCC had comparable rates of postoperative complications, but shorter hospital and rehab stays. Seizure outcomes appear favorable after SLCC, but larger groups, longer follow up, and improved patient matching are required. Funding: None