Abstracts

Rationale: In 2010 we presented a 10-year experience after VNS implant in 550 epilepsy patients. 220 are mentally challenged (MC), 330 have normal IQs (N). Methods: 10-year experience after VNS implant in 550 epilepsy patients. 220 are mentally challenged (MC), 330 have normal IQs (N) Results: 90% (MC) 95% (N) were able to taper at least one medication successfully after VNS implantation at 1 year. Seizure frequency reduction remains at 68% (N) and 59% (MC). A non-responder group (treatment-resistant) emerged from this study. 15 patients (MC) and 16 patients (N) had an average of 15 clusters or prolonged seizures per year requiring hospitalization despite continuous VNS stimulation protocols. All EEGs showed continuous spikes, spike and wave, or baseline studies. EEGs after baseline were performed at 3, 6, and 12 months. Demographics were similar for both groups. Etiology of seizures include migration disorder, encephalitis, and birth defects. Conclusions: In 10 of 15 (MC) non-reponders and 2 of 16 (N) non-responders correlate with: some neuronal migration disorder; EEGs at baseline have a significantly longer duration of spike wave activity with eventual appearance of spike and wave intervals after 6 months and a decrease in duration of spike and wave; clinically this small group of patients do not recover functional and ultimately remain in various stages of sub-clinical status epilepticus.