Pure endoscopic management of epileptogenic hypothalamic hamartomas.

Hypothalamic hamartomas (HH) are rare congenital malformations located in the region of the tuber cinereum and third ventricle. Their usual clinical presentation is characterized by gelastic/dacrystic seizures which often become pharmaco-resistant and progress to secondary focal/generalized intractable epilepsy causing mostly in children cognitive and behavioral problems (particularly in cases of progressive epileptic encephalopathy) and precocious puberty. Whereas gelastic seizures can be surgically controlled either by resection of the lesion or disconnection (tissue-destructive) procedures, aimed at functionally prevent the spreading of the epileptic burst; generalized seizures tend to respond better to HH excision rather than isolated neocortical resections, which generally fail to control them. Prospective analysis of 14 consecutive patients harboring HH treated in an 8-year period; 12 patients had unilateral and two bilateral HH. All patients were managed by pure endoscopic excision of the HH. The mean operative time was 48 min and mean hospital stay was 2 days; perioperative blood loss was negligible in all cases. Two patients showed a transient diabetes insipidus (DI); no transient or permanent postoperative neurological deficit or memory impairment was recorded. Complete HH excision was achieved in 10/14 patients. At a mean follow-up of 48 months, no wound infection, meningitis, postoperative hydrocephalus, and/or mortality were recorded in this series of patients. Eight patients became seizure free (Engel class I), 2 other experienced worthwhile improvement of disabling seizures (Engel class II); 2 patients were cured from gelastic attacks while still experiencing focal dyscognitive seizures; and 2, having bilateral HH (both undergoing unilateral HH excision), did not experience significant improvement and required later on a temporal lobectomy coupled to amygdalohyppocampectomy. Overall, the followings resulted to be predictive factors for better outcomes in terms of seizure control: (1) cases of unilateral, Delalande class B, HH, (2) shorter history of epilepsy. Endoscopic resection of HH proved, in our series, to be effective in achieving complete control or in reducing the frequency of seizures. Furthermore, this approach has confirmed its minimally invasive nature with a very low morbidity rate: of note, it allowed to better preserve short-term memory and hypothalamic function.

Efficacy and safety in frameless robot-assisted stereo-electroencephalography (SEEG) for drug-resistant epilepsy.

INTRODUCTION: Stereo-electroencephalography (SEEG) is an invasive procedure, used to identify the epileptogenic zone that can be surgically removed in order to treat drug-resistant epilepsy. Frameless robot-assisted positioning of depth electrodes permits a 3D approach with different obliquities and trajectories. The objective of the present study was to evaluate the morbidity and the accuracy related to this frameless procedure. PATIENTS AND METHODS: Sixty-six patients were managed wherein 901 electrodes were implanted during a 6-year-period. All patients had a postoperative CT-scan that was fused with preoperative MRI planning. In order to assess the accuracy of the procedure, the Euclidian distance was calculated between the coordinates of the planned trajectory and the actual position of the electrode at the entry point and at the target point for 857 electrodes. RESULTS: Among the 66 patients, one (1.5%) experienced a symptomatic brain haematoma and one (1.5%) a stroke-like migraine after radiation therapy (SMART) syndrome. There was no permanent morbidity or mortality. Compared to the classical SEEG approach, a higher rate of asymptomatic postoperative bleeding was found on the CT-scan in 8 patients (12.1%). Any infectious events were recorded. The median accuracy of frameless robotic SEEG procedure was equivalent to a 1.1mm error deviation (0.15-2.48) at the entry point and 2.09mm (1.06-3.72) at the target point respectively, with no differences for double obliquity trajectories. CONCLUSION: Frameless robot-assisted SEEG appears to be a safe procedure, providing sufficient accuracy in order to delineate the epileptogenic zone and represents a helpful tool in the pre-surgical management of refractory epilepsy.