Awaking anaesthesia and intraoperative cortico-subcortical electrostimulation in surgery for secondary epilepsy induced by lesions in cerebral eloquent regions

Abstract

Objective To discuss the application of awaking anesthesia and intraoperative cortico-subcortical electrostimulation in the surgery for patients with secondary epilepsy induced by lesions in eloquent areas. Methods A total of 11 patients initiated with epileptic seizure were collected in our study. All patients were right-handed and 5 had neurological dysfunction, and the mean Karnofsky performance status (KPS) scores were 87. Skull MRI and long-term video-EEG monitoring were performed for all patients, and 6 of them got functional MRI. The surgeries were performed under intravenous anesthesia: 4 got trachea intubation and the other 7 were performed pharyngeal esophageal intubation under awaking anesthesia. Electrocorticographic recordings were adopted to confirm the epileptogenic zone, and then cortical electrical stimulus was performed to locate the cortical functional area. Under subcortical electrostimulation monitoring, we resected the lesions by the methods of focal cortical resection or multiple subpial transaction (MST) according to the relation between epileptogenic zone and functional cortex; during the resection, subcortical electrostimulation was adopted to protect the tracts lay in the sub-cortex. Results Total resection was achieved in 10 patients, and subtotal excision in 1. The epileptogenic zone was performed cortical resection or pia mater-fiber transverse amputation.Two cases got transient hemiparalysis after operation. Followed up for 6-20 months, none of the patients had neurologic deficit, and the average KPS scores were 100. Epilepsies were well-controlled using only one antiepileptic drug. Conclusion Pharyngeal esophageal intubation under awaking anesthesia is safe and convenient. With the monitoring of intraoperative cortico-subcortical electrostimulation, we can resect the lesions up to the hilt and protect the eloquent areas effectively, and improve the life quality of patients. Key words: Awaking anesthesia; Intraoperative electrostimulation; Eloquent brain region; Secondary epilepsy