VERBAL MEMORY IN TEMPORAL LOBECTOMY PATIENTS WITH BILATERAL LANGUAGE: IMPLICATIONS FOR POSTOPERATIVE COGNITIVE OUTCOME
Abstract number :
2.138
Submission category :
Year :
2002
Submission ID :
1636
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Gail L. Risse, Britt E. Carlson, Ann Hempel, Robert C. Doss, John R. Gates. Minnesota Epilepsy Group, P.A.[reg], of United Hospital and Children[ssquote]s Hospitals and Clinics, St. Paul, MN; Clinical Professor, Department of Neurology, University of Minn
RATIONALE: Little is known about the lateralization of verbal memory in patients found to have some degree of bilateral language representation based on the intracarotid amobarbital procedure (IAP). The presence of some verbal memory capacity in the right hemisphere may be a positive prognostic indicator for verbal memory outcome following left temporal lobectomy. The objective of the present study was to review the evidence for right hemisphere verbal memory in bilateral language patients undergoing left temporal resection.
METHODS: The subjects were 22 adult chronic seizure patients who underwent left temporal lobectomy including resection of the hippocampus. All patients had definitive language lateralization per IAP. Fifteen (7M, 8F) were exclusively left hemisphere dominant for language, while 7 (3M, 4F) demonstrated some language capacity in the right hemisphere. Mean age at surgery and baseline IQ did not differ for the 2 groups. Verbal recall performance during IAP and pre- and postoperative delayed retention and recognition on a verbal selective reminding test were compared for the two groups using t-tests for independent samples.
RESULTS: Verbal recall during IAP left injection was higher for patients with bilateral language (B) compared to left dominant patients (L) (B=74% correct; L=25% correct). Verbal recall following right injection showed a trend favoring the left dominant group (B=44%; L=61%). These differences did not reach statistical significance. Pre to postoperative difference scores in delayed retention showed a greater decline for left dominant patients (-27%) compared to bilateral language cases (-15%). Pre to postoperative recognition difference scores (adjusted for intrusion errors) demonstarted a significantly greater loss for the left dominant group (-13%) compared to the bilateal patients (-2%; p[lt].01).
CONCLUSIONS: These results suggest that patients with some duplication of language functions in the right hemisphere may have developed some verbal memory capacity on the right side as well. These patients may be at lower risk for significant verbal memory decline following left temporal lobectomy with hippocampal resection. Suggested criteria for establishing bilateral language in the IAP will be discussed.