Memory deficits before and after temporal lobectomy: Effect of laterality and age of onset

Saykin, Andrew J.; Gur, Ruben C.; Sussman, Neil M.; O’Connor, Michael J.; Gur, Raquel E.

doi:10.1016/0278-2626(89)90029-8

Cited by 162 publications

(95 citation statements)

References 18 publications

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“…However, in contrast to previous studies on the crowding phenomenon (Saykin et al, 1989;Strauss et al, 1990;Carlsson et al, 1994;Helmstaedter et al, 1994;Mariotti et al, 1998;Staudt et al, 2002), no negative behavioral consequences could be ascertained in our subjects. Most importantly, we did not find major discrepancies between verbal and nonverbal performance.…”

Section: Neuropsychologic Implicationscontrasting

confidence: 99%

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Atypical Hemispheric Dominance for Attention: Functional MRI Topography

Flöel

Jansen

Deppe

et al. 2005

J Cereb Blood Flow Metab

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The right hemisphere is predominantly involved in tasks associated with spatial attention. However, left hemispheric dominance for spatial attention can be found in healthy individuals, and both spatial attention and language can be lateralized to the same hemisphere. Little is known about the underlying regional distribution of neural activation in these 'atypical' individuals. Previously a large number of healthy subjects were screened for hemispheric dominance of visuospatial attention and language, using functional Doppler ultrasonography. From this group, subjects were chosen who were 'atypical' for hemispheric dominance of visuospatial attention and language, and their pattern of brain activation was studied with functional magnetic resonance imaging during a task probing spatial attention. Right-handed subjects with the 'typical' pattern of brain organization served as control subjects. It was found that subjects with an inverted lateralization of language and spatial attention (language right, attention left) recruited left-hemispheric areas in the attention task, homotopic to those recruited by control subjects in the right hemisphere. Subjects with lateralization of both language and attention to the right hemisphere activated an attentional network in the right hemisphere that was comparable to control subjects. The present findings suggest that not the hemispheric side, but the intrahemispheric pattern of activation is the distinct feature for the neural processes underlying language and attention.

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Section: Neuropsychologic Implicationscontrasting

confidence: 99%

“…Differences in hemispheric side for lateralized brain functions need not be accompanied by impaired function, as proposed by lesion studies (Saykin et al, 1989;Strauss et al, 1990;Staudt et al, 2002). Rather, all patterns of cerebral lateralization may be implemented in the healthy human brain.…”

Section: Resultsmentioning

confidence: 88%

Atypical Hemispheric Dominance for Attention: Functional MRI Topography

Flöel

Jansen

Deppe

et al. 2005

J Cereb Blood Flow Metab

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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: 91%

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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“…The proposed classification framework was experimentally evaluated on synthetic data (mixtures of Gaussian distributions), on realistic brain lesiondeficit data generated by a simulator [33] conforming to a clinical study [44], and on real fMRI brain activation distributions obtained from a study that explores neuroanatomical correlates of semantic processing in Alzheimer's disease [45]. These datasets as well as the experimental results are described below.…”

Section: Resultsmentioning

confidence: 99%

“…The task consisted of an auditory presentation of word pairs (categories and possible exemplars) requiring a semantic decision (match-mismatch) [45]. Each subject was tested with the same timing and word set with a blocked design.…”

Section: Experiments With Clinical Datamentioning

confidence: 99%

Subjective Probability

2005

Dictionary of Statistics &Amp; Methodology

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SummaryObjective: The objective of this paper is to classify 3D medical images by analyzing spatial distributions to model and characterize the arrangement of the regions of interest (ROIs) in 3D space. Methods and material: Two methods are proposed for facilitating such classification. The first method uses measures of similarity, such as the Mahalanobis distance and the Kullback-Leibler (KL) divergence, to compute the difference between spatial probability distributions of ROIs in an image of a new subject and each of the considered classes represented by historical data (e.g., normal versus disease class). A new subject is predicted to belong to the class corresponding to the most similar dataset. The second method employs the maximum likelihood (ML) principle to predict the class that most likely produced the dataset of the new subject. Results: The proposed methods have been experimentally evaluated on three datasets: synthetic data (mixtures of Gaussian distributions), realistic lesion-deficit data (generated by a simulator conforming to a clinical study), and functional MRI activation data obtained from a study designed to explore neuroanatomical correlates of semantic processing in Alzheimer's disease (AD).

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Memory deficits before and after temporal lobectomy: Effect of laterality and age of onset

Cited by 162 publications

References 18 publications

Atypical Hemispheric Dominance for Attention: Functional MRI Topography

Atypical Hemispheric Dominance for Attention: Functional MRI Topography

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

Subjective Probability

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