Abstracts

Purpose: Naming ability is known to be at risk after left, language-dominant anterior temporal lobectomy, particularly in the absence of hippocampal sclerosis/late epilepsy onset age. It is not known whether this is secondary to resection of mesial temporal structures or lateral temporal lobe in which language areas may be reorganized. It has been postulated that selective amygdalohippocampectomy (SAH) may reduce the risk. Methods: We studied patients undergoing left SAH for unilateral temporal onset non-lesional epilepsy between 1997 and 1999 who were: 1) left hemisphere dominant for language on intracarotid amobarbital testing; 2) had hippocampus graded for absence or presence of sclerosis (HS-/HS+); 3) had no MRI change apart from those of HS, and; 4) had pre- and postoperative confrontation naming evaluated. Results: Eight patients met the criteria. Seven patients were HS+ and one HS-. Naming was stable in all the HS+ patients, but the HS- patient, a 41 year old female, underwent a Reliable Change Index decline on two tests of confrontation naming. Memory function also declined. Fluency and comprehension evaluated by the Controlled Oral Word Association Test and Token Test were stable indicating that other aspects of language were unaffected. Epilepsy onset age was 3 years. Invasive monitoring had demonstrated a mesial temporal ictal onset. There have been only rare seizures postoperatively. Conclusion: A selective mesial temporal resection may not reduce the risk to naming ability in cases of mesial temporal onset epilepsy where the hippocampus is normal. Further studies will be required to confirm this.