Hypothalamic hamartomas (HHs) are a known cause of refractory focal epilepsy. Advancement in microsurgical techniques and introduction of stereotactic ablative methods have led to improved complication rates, but the effect on seizure control is still to be determined. In this systematic review, we present a thorough analysis of published literature on the outcomes of various surgical treatments of HHs for refractory epilepsy.

A literature search using the MedLine, SCOPUS and Cochrane databases was conducted. All English language studies describing surgical treatment of HH with refractory epilepsy, with a minimum of three patients and a follow-up of at least one year, were identified.

An initial selection of 55 studies was reduced to 41 after combining studies from the same groups; 14 open, 4 endoscopic, 8 Gamma Knife radiosurgery (GKRS), 9 laser interstitial thermal therapy (LITT) and 6 radiofrequency thermocoagulation (RF-TC) studies were included. From a total of 832 patients, 209 underwent open (25.1%), 80 endoscopic (9.6%), 124 GKRS (14.9%), 229 LITT (27.5%) and 190 RF-TC (22.8%). Engel I or ILAE 1 or 2 was achieved in: open 115 (55.0%), endoscopic 38 (47.5%), GKRS 49 (39.5%), LITT 176 (76.9%) and RF-TC 128 (67.4%). Invasive surgeries (open and endoscopic) had a higher incidence of neurological complications (27.0%) than ablative surgeries (GKRS, LITT, RF-TC) (7.2%). Reoperation rates were higher for ablative surgeries (23.8%) than invasive surgeries (9.0%).

Surgical treatment of HH causing refractory epilepsy is effective. RF-TC and LITT surgery types have the highest Engel class I outcomes, and ablative surgeries have a lower neurological complication profile compared to open and endoscopic approaches.

Radiofrequency thermocoagulation (RF-TC) is a minimally invasive ablative option for refractory focal epilepsy.

A retrospective chart review was conducted of all patients who underwent stereoelectroencephalography (SEEG)-guided RF-TC at our institution.

Fourteen patients underwent robot-guided electrode implantation and subsequent RF-TC. After RF-TC, one of the three patients with PVNH was seizure free, one had 18 months of seizure freedom (Engel 2b), and one required temporal neocortical/PVNH resection (Engel 1a). One of the four patients with focal cortical dysplasia (FCD) was seizure free (Engel 1a), two attained seizure freedom after resection (Engel 1a and 1b), while one continues to have significant seizures (Engel 4b). One patient with cavernoma and low central area epileptogenic zone (EZ) did not benefit from RF-TC and is planned for resection. Two of the MRI-negative patients achieved seizure freedom for 3 months and 1 year, respectively, subsequently requiring resection (Engel 1a). One remains seizure free at 4 weeks. Three had seizure recurrence immediately (Engel 4b). With RF-TC alone, two patients (14%) achieved Engel 1a, two were seizure free at 1 year, one had 3 months of seizure freedom, while the rest had recurrence immediately or within a few weeks. 7/14 patients underwent secondary interventions after RF-TC. Overall, seven patients achieved Engel 1a or 1b, one each 2b and 3a, and five Engel 4b.

At our institution, RF-TC is a safe ablative procedure for refractory focal epilepsy. It can serve as a segue to secondary interventions and appears promising in PVNH cases. Its role in MRI-negative cases is less clear.