VERBAL MEMORY OUTCOME FOLLOWING LEFT ATL IN PATIENTS WITH NORMAL PREOPERATIVE VERBAL MEMORY AND LEFT MESIAL TEMPORAL LOBE SCLEROSIS
Abstract number :
1.356
Submission category :
Year :
2003
Submission ID :
3937
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Roy Martin, Anthony Lagalbo, Stephen Sawrie, Jorge Burneo, Robert Knowlton, Melissa Mendez, Avinash Prasad, Edward Faught, Ruben Kuzniecky Neurology, University of Alabama at Birmingham, Birmingham, AL; Psychology, University of Alabama at Birmingham, Bir
Previous studies have shown that normal preoperative verbal memory (VM) is a risk factor for VM decline following left anterior temporal lobectomy (ATL). This pattern of outcome is typically associated with resection to normal or minimally atrophic left mesial temporal lobe structures. However, the presence of a more severe degree of left mesial temporal sclerosis (MTS) is thought to reduce the risk to postoperative VM. To date, limited information is available regarding relative risk to VM in patients with both normal preoperative VM and left MTS. This study investigated VM change following left ATL in patients who had preoperative MRI verified evidence of exclusive left MTS and normal baseline VM.
Two groups of left MTS patients were identified: those exhibiting normal preoperative VM (NVM; n = 17) and those with impaired preoperative verbal memory (ImVM; n = 29). Patients were classified as having normal memory if performances on both Acquisition (learning across trials 1-5) and Retrieval (long delayed free recall) portions of the California Verbal Learning Test were above a T-score of 40 ([gt]16%ile). Verbal memory outcome was established by incorporating standardized regression-based change scores (SRB). Change scores are expressed in z-score units.
Patients were similar across age, gender, education, Full Scale IQ, age at seizure onset, and seizure duration (years). All patients had FSIQ [gt]70 and were right-handed. Wada testing was administered to 19 patients (10 NVM, 9 ImVM patients). All patients were left speech/language dominant. Postoperatively, groups demonstrated similar levels of decline on the CVLT Acquisition variable (p [gt].05; SRB z-score change: NVM = -1.05, ImVM = -1.02). However, a statistical trend was found (p [lt] .09) in which the NVM group displayed poorer outcome on the CVLT Retrieval outcome variable (SRB z-score change: NVM = -2.50, ImVM = -1.55). Postoperative seizure outcome did not correlate with either CVLT Acquisition or Retrieval SRB change scores. Ipsilateral Wada recognition memory score correlated significantly with the CVLT Retrieval SRB change score (r2= -.48, p [lt] .04), but not for the contralateral score (r2 = .01, NS).
These results suggest that the presence of preoperative MRI verified left MTS does not exclude the risk for postoperative VM decline in patients with normal preoperative VM function. Our findings indicate that the structural integrity of the mesial temporal lobe is not an exclusive factor in determing risk to VM decline after left ATL. Our findings lend support to the notion of functional adequacy of the ipsilateral mesial temporal lobe in explaining verbal memory outcome.