Abstracts

Rationale: Bilateral periventricular nodular heterotopia (BiPNH) is often associated to refractory seizures. Focal resections are usually inadequate to control seizures due to the multifocal nature of this epileptic syndromes. The use of vagus nerve stimulation and radiofrequency lesions have been described with variable and often transient outcome regarding seizures. We describe the use of hippocampal deep brain stimulation (Hip-DBS) for treatment of refractory seizures in a patient with BiPNH).  Methods: M., a 34-year-old woman had epilepsy since the age of 23 years. She had daily autonomic simple partial seizures followed by complex partial seizures with automatisms; generalized tonic-clonic seizures occurred once per week. Ictal and interictal EEG showed bitemporal discharges; seizures were recorded from both temporal lobes independently. MRI showed symmetric BiPNH. She was taking lamotrigine 600md/day, oxcarbazepine 1200mg/day and clobazam 40mg/day. She has been previously submitted to vagus nerve stimulation, which reduced the seizure frequency by 60%; she remained with daily complex partial seizures and weekly generalized tonic-clonic seizures. Results: She was submitted to bilateral Hip-DBS under general anesthesia. Final stimulation parameters were: 2.5V, 300usec, 130Hz, continuous bipolar stimulation (catode over the hippocampal head; anode over the posterior hippocampal body). At 3 years of follow-up, she presented 1 complex partial seizure per trimester and no generalized tonic-clonic seizures. No additional memory deficit was noted. There was no side effects related to Hip-DBS.  Conclusions: Hip-DBS led to a dramatic seizure reduction in this patient with temporal lobe epilepsy and BiPNH. Hip-DBS might prove to be a good treatment option in this patient population. BiPNH is a rare disease; larger series and longer follow-up would be needed to further evaluate Hip-DBS efficacy in this setting. Funding: No funding