Abstracts

Rationale: Background: PVNH is a neuronal migration disorder and is the most common form of neuronal heterotopia. PVNH can lead to seizures that are typically drug-resistant. Advances in minimally invasive surgery provided novel interventions for treatment of epilepsy associated with structural causes including nodular heterotopia. We report our experience with PVNH-associated epilepsy that was localized with stereo-electroencephalography (SEEG) and then treated with laser interstitial thermal therapy (LITT). Methods: We reviewed our prospectively maintained database of epilepsy patients to identify eligible cases. We included patients that had a confirmed diagnosis of PVNH associated epilepsy that underwent intracranial recordings using SEEG, then followed by laser ablation. Seizure outcomes were reported using the Engel scale. Results: A total of 10 patients (6 females and 4 males) were identified. There was a total of 16 separate foci of PVNH in this population that were targeted with ablation after being found to be epileptogenic. Of the 6 patients with follow up greater than 1 year, 66% had an Engel 1a outcome, one was an Ic and one had a IIIa outcome. Four patients had follow-up at 3 years, and they had remained stable from the one-year timepoint. Conclusions: SEEG successfully discriminates between cortical and nodular onset of seizures in PVNH. MRI guided LITT for PVNH-associated epilepsy is a feasible, safe and efficacious intervention. A careful intracranial evaluation helps determine the role of PVNH in the epileptogenic network and can guide therapy to result in seizure freedom. Funding: No funding