RESULTS OF VNS THERAPY IN PATIENTS WITH REFLEX EATING SEIZURES
A Cukiert, JA Burattini, PP Mariani, CM Cukiert, C Baise-Zung, M Argentoni-Baldochi, CR Forster, VA Mello.
Epilepsy Surgery Program, Hospital Brigadeiro, São Paulo SP, Brazil
VNS therapy has been used in patients with heterogeneous epileptic syndromes. More recently, an attempt to study more homogeneous populations that would be more suitable for implantation had been undertaken. VNS is using the vagus nerve, which has extensive projections to gastrointestinal organs, to reach the central nervous system. Some patients have eating reflex seizures, alone or in combination with non-reflex seizures. We hypothesized that VNS therapy would have a differential effect in this subset of patients.
Patient 1: This 23 years-old, very thin man had daily refractory epigastric simple partial and complex partial seizures since the age of 8 years. Ninety-percent of the seizures occurred during meals, which usually needed to be interrupted. His MRI showed bilateral perysilvian polimicrogiria and his interictal EEG showed independent bitemporal spiking. He was submitted VNS: final parameters were 2.0mA, 500Usec and 30Hz. All his reflex seizures disappeared. He remained with non-reflex complex partial seizures (once a month). He gained weight and has been able to adequately feed after VNS.
Patient 2: This 34 years-old woman had daily refractory complex partial seizures since the age of 6 years. Seventy-percent of her seizures occurred during meals. Her MRI was normal. She had been previously submitted to right temporo-occipital resection at other institution; this procedure did not alter her seizure frequency and introduced a severe memory deficit and left-side hemianopsia. Post-resection video-EEG recording at our institution recording showed that her seizures were coming from the left brain side. She was submitted VNS: final parameters were 2.5mA, 500Usec and 30Hz. Ninety-percent of her reflex seizures disappeared. She remained with non-reflex complex partial seizures (once every 15 days).
Eating reflex seizures responded extremely well to VNS. The improvement in seizure frequency was much higher in these 2 patients then usually expected for patients with complex partial seizures. We postulated that this differential seizure frequency outcome was related to both VNS anti-epileptic activity and modulation of neural signaling from/to the gastrointestinal organs. VNS might prove to be the therapy of choice in patients with refractory eating epilepsy that are not amenable for resective surgery.