MORBIDITY OF EPIDURAL STRIP ELECTRODE IMPLANTATION FOR EPILEPSY PRESURGICAL EVALUATION

We report the morbidity associated with long-term seizure monitoring i n 95 patients implanted with epidural strip electrodes. Subtemporal ep idural strip electrodes were placed through bilateral temporal craniec tomies, using the standard approach to the Gasserian ganglion. The sil astic strip electrodes had four to six electrode contacts. Twelve pati ents also had additional subdural strips placed. Mean number of strip electrodes per patient was 5.3 strips (range 4-8). Mean duration of im plantation was 5.1 days (range 2-11). Complications included epidural hematoma (1.1%), epidural fluid collection (2.1%), and cranial nerve i njury (9.5%), for a total morbidity of 12.7%. Nine patients developed transient cranial nerve injuries (three V, seven VII). In five patient s, cranial nerve injuries were mild and resolved in 2-8 weeks. Four pe ripheral VIIth nerve injuries persisted to a mild degree after 3-month follow-up. Nine complications occurred with the first 41 implantation s during the first 5 years of this series; only four complications wer e associated with the 54 subsequent implantations in the last 4 years. The morbidity of epidural implantations was low, and no significant p ermanent morbidity occurred.