Seizure freedom of Epilepsia Partialis Continua (EPC) with vagus nerve stimulation (VNS) therapy: A case report

Vagus nerve stimulation (VNS) is generally considered as a palliative treatment for patients with drug-resistant partial onset epilepsy. We report a case that a patient with drug-resistant generalized onset epilepsy, Epilepsia Partialis Continua (EPC) became seizure free for 13 months with VNS combined with antiepileptic medication regimens. A 21-year-old, right-handed man started having seizures at the age of 18. He reported countless limbs shaking for about 10 s, and occasional generalized tonic–clonic seizures at a frequency of 5–7 times per year. He was initially treated with valproic acid (VPA) and carbamazepine (CBZ) with minimal benefits. Then he was treated with lamotrigine (LTG) 200 mg daily, Levetiracetam (LEV) 1250 mg daily and topiramate (TPM) 200 mg daily with minimal benefits for the last several months. His long-term video-EEG monitoring revealed small spike wave discharges. Sometimes he couldn't say a word or have dinner for the twitch of the mouth. A vagus nerve stimulator was subsequently implanted in Sept 2011. Initial stimulation parameters were: current output 0.25 mA, frequency 30 Hz, pulse width 250 ms, 30 s signal on time, and 5 min signal off time. The patient had two wild twitches of the mouth per week. Then his stimulation current output was changed to 0.50 mA, and his seizure became countless as pre-operation. Fortunately, he became seizure free after his stimulation current reverted to 0.25 mA. After one month of seizure freedom, the patient withdrew his LEV and TPM. He has remained seizure free for almost 9 months, during which time he has been gainfully employed.