Does the intracarotid amobarbital procedure predict global amnesia after temporal lobectomy?

Purpose: The intracarotid amobarbital procedure (IAP) is widely used to hel p predict who might be at risk for postoperative amnesia after unilateral t emporal lobectomy for intractable seizures. We describe the memory outcome in 10 patients who underwent standard temporal lobectomy, including mesial temporal structures, despite failing the memory portion of the IAP after in jections both ipsilateral and contralateral to the resected seizure focus. Methods: Data for seven of the study subjects were obtained through a retro spective review of patients assessed on a surgical epilepsy unit during a 1 5-year period who failed the Montreal Neurological Institute IAP memory pro tocol after both ipsilateral and contralateral injections and subsequently underwent unilateral temporal lobectomy. More recently, we have studied tem poral lobectomy patients who failed the Medical College of Georgia memory p rotocol after both ipsilateral and contralateral injections (n = 3). Preope rative and postoperative memory test scores were compared, and data regardi ng sei zure outcome and self-perception of postoperative memory were collec ted. Results: At follow-up, none of the patients presented with a pattern indica tive of a global amnesia, and 80% demonstrated >90% improvement in their se izure disorder or were seizure-free. Conclusions: These findings indicate that bilateral memory failure on the L AP does not preclude the removal of an epileptogenic temporal lobe or a suc cessful surgical outcome. In addition, the findings raise questions regardi ng the validity of the IAP and the possibility that memory may be reorganiz ed in patients with a long history of temporal lobe epilepsy.