Right hippocampal contribution to visual memory: a presurgical and postsurgical study in patients with temporal lobe epilepsy

Gleißner, Ulrike; Helmstaedter, Christoph; Elger, Christian E.

doi:10.1136/jnnp.65.5.665

Cited by 136 publications

(98 citation statements)

References 16 publications

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“…For the right temporal lobe there is some evidence that damage specifically in temporomesial structures may be the cause of impairments in non-verbal memory functions. Patients with hippocampal damage showed preoperatively [73] and postoperatively [74] impaired visual memory performance, whereas patients without hippocampal damage exhibited no deficiencies in visual memory. In line with previous operative studies, our results from MCI elderly adults with severe atrophy suggest a special involvement of MTA in visual memory performance.…”

Section: Discussionmentioning

confidence: 99%

Relationship between Atrophy of the Medial Temporal Areas and Cognitive Functions in Elderly Adults with Mild Cognitive Impairment

et al. 2012

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Aim: The current study sought to determine which types of cognitive function are related to atrophy of the bilateral medial temporal areas including the entorhinal cortex (MTA-ERC) in elderly adults. Methods: The subjects were 96 elderly adults (mean age 75.3 years) with mild cognitive impairment. Subjects underwent Wechsler Memory Scale-Revised, logical memory I and II (WMS-R, LM I and II), Rey complex figure retention tests after 3 and 30 min (RCF-3 min and RCF-30 min), digit span backword (DSB), digit symbol-coding (DSC), Stroop Color and Word Test-Interference List (SCWT-IL) as well as magnetic resonance imaging (MRI) and were divided into elderly adults without or with mild to moderate MTA-ERC atrophy, and those with severe atrophy. Results: In all subjects, MTA-ERC atrophy showed significant relationships with age (r = 0.43), education (r = –0.25), WMS-R, LM I (r = –0.21), DSC (r = –0.32), and SCWT-IL (r = 0.32). The mild to moderate atrophy group showed significant relationships between MTA-ERC atrophy and age (r = 0.34), DSC (r = –0.28), and SCWT-IL (r = 0.25). In contrast, in the severe atrophy group, MTA-ERC atrophy was correlated significantly with RCF-3 min (r = –0.70) and RCF-30 min (r = –0.74). The linear regression model included demographic variables and cognitive tests; two variables to survive the step-wise analysis were age (β = 0.374) and SCWT-IL (β = 0.247) in all subjects. Age (β = 0.301), and RCF-30 min (β = –0.521) and age (β = 0.460) remained as a significant variable in the mild to moderate atrophy and severe atrophy groups, respectively. Conclusion: Executive function tests such as SCWT-IL may be useful as a screening tool to identify mild to moderate MTA-ERC atrophy and a decline in the RCF test may suggest severe MTA-ERC atrophy in elderly adults with MCI.

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Section: Discussionmentioning

confidence: 99%

Relationship between Atrophy of the Medial Temporal Areas and Cognitive Functions in Elderly Adults with Mild Cognitive Impairment

et al. 2012

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“…Analyses were based on "learning capacity" (performance in the last trial, which has been shown to be sensitive for right temporal lobe dysfunction and right mesial pathology in right TLE. 24,25 Psychomotor speed/attention was assessed by a letter cancellation test. 26 Phonemic word fluency was assessed by a subtest of a German intelligence test.…”

Section: Cognitive Assessmentsmentioning

confidence: 99%

Chronic epilepsy and cognition: A longitudinal study in temporal lobe epilepsy

Helmstaedter¹,

Kurthen²,

Lux

et al. 2003

Annals of Neurology

645

387

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It remains unclear whether uncontrolled epilepsy causes mental decline. This longitudinal study contrasts change of memory and nonmemory functions in 147 surgically and 102 medically treated patients with temporal lobe epilepsy. All participants were evaluated at baseline (T1) and after 2 to 10 years (T3). Surgical patients underwent additional testing 1 year postoperatively (T2). Data were analyzed on an individual and group level. Sixty-three percent of the surgical and 12% of the medically treated patients were seizure-free at T3. Fifty percent of the medically treated and 60% of the surgical patients showed significant memory decline at T3 with little change in nonmemory functions (difference not significant). Surgery anticipated the decline seen in the medically treated group and exceeded it when surgery was performed on the left, or if seizures continued postoperatively. Seizure-free surgical patients showed recovery of nonmemory functions at T2 (p < 0.001) and of memory functions at T3 (T3, p = 0.03). Multiple regression indicated retest interval, seizure control, and mental reserve capacity as predictors of performance changes. In addition, psychosocial outcome was better when seizures were controlled. In conclusion, chronic temporal lobe epilepsy is associated with progressive memory impairment. Surgery, particularly if unsuccessful, accelerates this decline. However, memory decline may be stopped and even reversed if seizures are fully controlled.

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“…Damage incurred by left-sided mesial temporal lobe epilepsy is characterized by material-specific verbal memory deficits (Hermann et al, 1997). Analogous findings with right mesial temporal lobe epilepsy and non-verbal memory are less consistent, except for patients with hippocampal sclerosis, where specific visual memory deficits have been found (Gleissner et al, 1998a). This inconsistency may be partly dependent on the characteristics of the spatial cues, in particular how easily they can be verbalized (Barkas et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Fluoxetine restores spatial learning but not accelerated forgetting in mesial temporal lobe epilepsy

Barkas

Redhead

Taylor

et al. 2012

Brain

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Learning and memory dysfunction is the most common neuropsychological effect of mesial temporal lobe epilepsy, and because the underlying neurobiology is poorly understood, there are no pharmacological strategies to help restore memory function in these patients. We have demonstrated impairments in the acquisition of an allocentric spatial task, in patients with unilateral hippocampal sclerosis. We also show that patients have accelerated forgetting of the learned spatial task and that this is associated with damage to the non-dominant hippocampal formation. We go on to show a very similar pattern of chronic allocentric learning and accelerated forgetting in a status epilepticus model of mesial temporal lobe epilepsy in rats, which is associated with reduced and abnormal hippocampal neurogenesis. Finally, we show that reversal of the neurogenic deficit using fluoxetine is associated with reversal of the learning deficit but not the accelerated forgetting, pointing to a possible dissociation in the underlying mechanisms, as well as a potential therapeutic strategy for improving hippocampal-dependant learning in patients with mesial temporal lobe epilepsy.

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Right hippocampal contribution to visual memory: a presurgical and postsurgical study in patients with temporal lobe epilepsy

Cited by 136 publications

References 16 publications

Relationship between Atrophy of the Medial Temporal Areas and Cognitive Functions in Elderly Adults with Mild Cognitive Impairment

Relationship between Atrophy of the Medial Temporal Areas and Cognitive Functions in Elderly Adults with Mild Cognitive Impairment

Chronic epilepsy and cognition: A longitudinal study in temporal lobe epilepsy

Fluoxetine restores spatial learning but not accelerated forgetting in mesial temporal lobe epilepsy

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