Selective memory improvement and impairment in temporal lobectomy for epilepsy

Novelly, Robert A.; Augustine, Elizabeth; Mattson, Richard H.; Glaser, Gilbert H.; Williamson, Pétér D.; Spencer, Dennis D.; Spencer, Susan S.

doi:10.1002/ana.410150112

Cited by 262 publications

(104 citation statements)

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“…undergoing left ATL exhibited improvement in recall of visual designs, while those undergoing right ATL demonstrated improvement in paragraph recall (3). Similar findings were seen in other centers.…”

Section: What Happens To the Brain Following Anterior Temporal Lobe Rsupporting

confidence: 86%

What Happens to the Brain following Anterior Temporal Lobe Resection?

Barr¹

2016

Epilepsy Curr

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CommentaryMemory changes are a well-known effect of anterior temporal lobe resection (ATL). Most attention has focused on decreased postoperative memory functioning, with results of a metaanalysis demonstrating memory decline on neuropsychological tests of verbal memory in 44% of individuals undergoing dominant hemisphere ATL, with a rate of decline observed in only 20% of those patients undergoing ATL on the nondominant hemisphere (1). Numerous attempts have been made to predict which clinical and demographic factors might provide the best predictors for postoperative memory decline. There are also ongoing attempts to modify existing surgical procedures or develop new procedures with the aim of reducing the severity and extent of memory loss associated with most standard surgical approaches (2).Receiving much less attention, however, are those patients who exhibit an improvement in memory functioning following ATL. While general memory improvement has been noted in some studies, Novelly and colleagues were the first to identify this in patients undergoing ATL, a profile selective improvement of modality specific memory functioning associated with the hemisphere contralateral to surgery. In that study's analysis of group changes, the authors found that patients

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Section: What Happens To the Brain Following Anterior Temporal Lobe Rsupporting

confidence: 86%

What Happens to the Brain following Anterior Temporal Lobe Resection?

Barr¹

2016

Epilepsy Curr

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“…Previous reports using unstandardized memory outcome techniques have found that left ATL groups display statistically significant declines on measures of verbal memory and visual confrontation naming after dominant temporal lobe resection (28,30,3 1). Significant visual memory decline also has been reported after right ATL, although not as consistently (32)(33)(34)(35). These within-group findings suggest that these statistically significant results may not be clinically significant after controlling for normal test-retest variability.…”

Section: Discussionmentioning

confidence: 90%

Individual Memory Change After Anterior Temporal Lobectomy: A Base Rate Analysis Using Regression‐Based Outcome Methodology

et al. 1998

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Summary:Purpose: To characterize patterns of base rate change on measures of verbal and visual memory after anterior temporal lobectomy (ATL) using a newly developed regression-based outcome methodology that accounts for effects of practice and regression towards the mean, and to comment on the predictive utility of baseline memory measures on postoperative memory outcome.Methods: Memory change was operationalized using regression-based change norms in a group of left (n = 53) and right (n = 48) ATL patients. All patients were administered tests of episodic verbal (prose recall, list learning) and visual (figure reproduction) memory, and semantic memory before and after ATL.Results: ATL patients displayed a wide range of memory outcome across verbal and visual memory domains. Significant performance declines were noted for 25-50% of left ATL patients on verbal semantic and episodic memory tasks, while one-third of right ATL patients displayed significant declines in immediate and delayed episodic prose recall. Significant performance improvement was noted in an additional one-third of right ATL patients on delayed prose recall. Base rate change was similar between the two ATL groups across immediate and delayed visual memory. Approximately one-fourth of all patients displayed clinically meaningful losses on the visual memory task following surgery. Robust relationships between preoperative memory measures and nonstandardized change scores were attenuated or reversed using standardized memory outcome techniques.Conclusions: Our results demonstrated substantial group variability in memory outcome for ATL patients. These results extend previous research by incorporating known effects of practice and regression to the mean when addressing meaningful neuropscyhological change following epilepsy surgery. Our findings also suggest that future neuropsychological outcome studies should take steps towards controlling for regression-tothe-mean before drawing predictive conclusions. Key Words: Epilepsy-Memory-Temporal Iobectomy-Postoperative outcome-Neuropsychology .Unilateral anterior temporal lobectomy (ATL) is an effective surgical intervention for the treatment of medically intractable epilepsy. Approximately 60-80% of patients display postoperative seizure reduction or become seizure free subsequent to removal of epileptogenic brain tissue (1). However, resecting temporal lobe structures poses risks for declines in declarative memory function, especially for individuals undergoing ATL of the language-dominant hemisphere (2-4).Statistically significant decrements on standardized verbal memory tests (e.g., California Verbal Learning Test, Wechsler Memory Scales) (5-7) are commonly reAccepted April 24, 1998. ported in upwards of 40-60% of left ATL patients and in 10-30% of right ATL patients (8,9). Phillips and McGlone (10) pointed out that >50% of their left ATL patients displayed both reliable pre-to postsurgery gains and pre-to postsurgery losses across tests of episodic verbal memory (e.g., WMS Logical Memory and Pair...

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“…It was frequently reported that left temporal lobectomy provokes verbal memory deficit, and right temporal lobectomy, visual memory deficit (50)(51)(52)(53)(54)(55). However, there are some discrepancies in the literature concerning the neuropsychological significance of quantitative MR results (23, [56][57][58][59][60][61].…”

Section: Discussionmentioning

confidence: 99%

Combined Measurements of Hippocampal N‐Acetyl‐Aspartate and T₂ Relaxation Time in the Evaluation of Mesial Temporal Lobe Epilepsy: Correlation with Clinical Severity and Memory Performances

et al. 1999

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Summary:Purpose: In this study we tried to find a correlation between the clinical severity and memory performances, by comparing proton magnetic resonance (MR) spectroscopy and T, relaxation time measurements in the hippocampi, in a homogeneous group of 27 patients with unilateral mesial temporal lobe epilepsy with ipsilateral hippocampal sclerosis on MR imaging, with a view to answer the following questions: (a) how sensitive is this approach for the assessment of the apparently normal contralateral hippocampus, (b) do the results relate to the clinical severity, and (c) does it allow evaluation of the degree of hippocampal dysfunction.Methods: Volume-selective proton MR spectroscopy of the head of both hippocampi was performed at 3 T, by using the PRESS sequence, with an echo time of 135 ms, to estimate NAA/(Cho + Cr) ratios. The relaxation times were measured at 0.28 T, by using a conventional Carr-Purcell-Meiboom-Gill sequence, with a repetition time of 2,000 ms, an echo time of 15 ms, and 48 echoes. Conclusions: We showed that the combination of NAA and T, relaxation time measurements can be used to examine the degree of ipsi-and contralateral hippocampal dysfunction or injuries and their relations with memory performances in the presurgical evaluation of patients. Key Words: EpilepsyTemporal lobe-Hippocampus-Magnetic spectroscopyMagnetic resonance imaging.Mesial temporal sclerosis, characterized by selective neuronal loss and reactive gliosis in the hippocampus and other mesial temporal structures, is a common pathologic finding in mesial temporal lobe epilepsy (mTLE). Within the past 10 years, the reliable identification of

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Selective memory improvement and impairment in temporal lobectomy for epilepsy

Cited by 262 publications

References 14 publications

What Happens to the Brain following Anterior Temporal Lobe Resection?

What Happens to the Brain following Anterior Temporal Lobe Resection?

Individual Memory Change After Anterior Temporal Lobectomy: A Base Rate Analysis Using Regression‐Based Outcome Methodology

Combined Measurements of Hippocampal N‐Acetyl‐Aspartate and T₂ Relaxation Time in the Evaluation of Mesial Temporal Lobe Epilepsy: Correlation with Clinical Severity and Memory Performances

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Selective memory improvement and impairment in temporal lobectomy for epilepsy

Cited by 262 publications

References 14 publications

What Happens to the Brain following Anterior Temporal Lobe Resection?

What Happens to the Brain following Anterior Temporal Lobe Resection?

Individual Memory Change After Anterior Temporal Lobectomy: A Base Rate Analysis Using Regression‐Based Outcome Methodology

Combined Measurements of Hippocampal N‐Acetyl‐Aspartate and T2 Relaxation Time in the Evaluation of Mesial Temporal Lobe Epilepsy: Correlation with Clinical Severity and Memory Performances

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Combined Measurements of Hippocampal N‐Acetyl‐Aspartate and T₂ Relaxation Time in the Evaluation of Mesial Temporal Lobe Epilepsy: Correlation with Clinical Severity and Memory Performances