Hippocampal atrophy and quantitative EEG markers in mild cognitive impairment in temporal lobe epilepsy versus extra-temporal lobe epilepsy

Abstract Epilepsy incidence and prevalence peaks in older adults yet systematic studies of brain ageing and cognition in older adults with epilepsy remain limited. Here, we characterize patterns of cortical atrophy and cognitive impairment in 73 older adults with temporal lobe epilepsy (>55 years) and compare these patterns to those observed in 70 healthy controls and 79 patients with amnestic mild cognitive impairment, the prodromal stage of Alzheimer’s disease. Patients with temporal lobe epilepsy were recruited from four tertiary epilepsy surgical centres; amnestic mild cognitive impairment and control subjects were obtained from the Alzheimer’s Disease Neuroimaging Initiative database. Whole brain and region of interest analyses were conducted between patient groups and controls, as well as between temporal lobe epilepsy patients with early-onset (age of onset <50 years) and late-onset (>50 years) seizures. Older adults with temporal lobe epilepsy demonstrated a similar pattern and magnitude of medial temporal lobe atrophy to amnestic mild cognitive impairment. Region of interest analyses revealed pronounced medial temporal lobe thinning in both patient groups in bilateral entorhinal, temporal pole, and fusiform regions (all P < 0.05). Patients with temporal lobe epilepsy demonstrated thinner left entorhinal cortex compared to amnestic mild cognitive impairment (P = 0.02). Patients with late-onset temporal lobe epilepsy had a more consistent pattern of cortical thinning than patients with early-onset epilepsy, demonstrating decreased cortical thickness extending into the bilateral fusiform (both P < 0.01). Both temporal lobe epilepsy and amnestic mild cognitive impairment groups showed significant memory and language impairment relative to healthy control subjects. However, despite similar performances in language and memory encoding, patients with amnestic mild cognitive impairment demonstrated poorer delayed memory performances relative to both early and late-onset temporal lobe epilepsy. Medial temporal lobe atrophy and cognitive impairment overlap between older adults with temporal lobe epilepsy and amnestic mild cognitive impairment highlights the risks of growing old with epilepsy. Concerns regarding accelerated ageing and Alzheimer’s disease co-morbidity in older adults with temporal lobe epilepsy suggests an urgent need for translational research aimed at identifying common mechanisms and/or targeting symptoms shared across a broad neurological disease spectrum.

Download Full-text

The efficacy of a voxel-based morphometry on the analysis of imaging in schizophrenia, temporal lobe epilepsy, and Alzheimer's disease/mild cognitive impairment: a review

Neuroradiology ◽

10.1007/s00234-010-0717-2 ◽

2010 ◽

Vol 52 (8) ◽

pp. 711-721 ◽

Cited By ~ 39

Author(s):

Shingo Kakeda ◽

Yukunori Korogi

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Voxel Based Morphometry

Download Full-text

Prediction of Cognitive Decline in Temporal Lobe Epilepsy and Mild Cognitive Impairment by EEG, MRI, and Neuropsychology

Computational Intelligence and Neuroscience ◽

10.1155/2020/8915961 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16

Author(s):

Yvonne Höller ◽

Kevin H. G. Butz ◽

Aljoscha C. Thomschewski ◽

Elisabeth V. Schmid ◽

Christoph D. Hofer ◽

...

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Temporal Lobe Epilepsy ◽

Executive Functions ◽

Cognitive Decline ◽

Temporal Lobe ◽

Divided Attention ◽

Verbal Memory ◽

Feature Subset Selection ◽

Wavelet Features

Cognitive decline is a severe concern of patients with mild cognitive impairment. Also, in patients with temporal lobe epilepsy, memory problems are a frequently encountered problem with potential progression. On the background of a unifying hypothesis for cognitive decline, we merged knowledge from dementia and epilepsy research in order to identify biomarkers with a high predictive value for cognitive decline across and beyond these groups that can be fed into intelligent systems. We prospectively assessed patients with temporal lobe epilepsy (N = 9), mild cognitive impairment (N = 19), and subjective cognitive complaints (N = 4) and healthy controls (N = 18). All had structural cerebral MRI, EEG at rest and during declarative verbal memory performance, and a neuropsychological assessment which was repeated after 18 months. Cognitive decline was defined as significant change on neuropsychological subscales. We extracted volumetric and shape features from MRI and brain network measures from EEG and fed these features alongside a baseline testing in neuropsychology into a machine learning framework with feature subset selection and 5-fold cross validation. Out of 50 patients, 27 had a decline over time in executive functions, 23 in visual-verbal memory, 23 in divided attention, and 7 patients had an increase in depression scores. The best sensitivity/specificity for decline was 72%/82% for executive functions based on a feature combination from MRI volumetry and EEG partial coherence during recall of memories; 95%/74% for visual-verbal memory by combination of MRI-wavelet features and neuropsychology; 84%/76% for divided attention by combination of MRI-wavelet features and neuropsychology; and 81%/90% for increase of depression by combination of EEG partial directed coherence factor at rest and neuropsychology. Combining information from EEG, MRI, and neuropsychology in order to predict neuropsychological changes in a heterogeneous population could create a more general model of cognitive performance decline.

Download Full-text

What do temporal lobe epilepsy and progressive mild cognitive impairment have in common?

Frontiers in Systems Neuroscience ◽

10.3389/fnsys.2014.00058 ◽

2014 ◽

Vol 8 ◽

Cited By ~ 6

Author(s):

Yvonne HÃ¶ller ◽

Eugen Trinka

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe

Download Full-text

Quantitative EEG Markers in Mild Cognitive Impairment: Degenerative versus Vascular Brain Impairment

International Journal of Alzheimer s Disease ◽

10.1155/2012/917537 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 16

Author(s):

D. V. Moretti ◽

O. Zanetti ◽

G. Binetti ◽

G. B. Frisoni

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Spectral Band ◽

Quantitative Eeg ◽

Hippocampal Atrophy ◽

Relative Power ◽

Resonance Imaging ◽

Band Power ◽

The Individual ◽

The Relationship

We evaluated the relationship between brain rhythmicity and both the cerebrovascular damage (CVD) and amygdalohippocampal complex (AHC) atrophy, as revealed by scalp electroencephalography (EEG) in a cohort of subjects with mild cognitive impairment (MCI). All MCI subjects underwent EEG recording and magnetic resonance imaging. EEGs were recorded at rest. Relative power was separately computed for delta, theta, alpha1, alpha2, and alpha3 frequency bands. In the spectral band power the severity of CVD was associated with increased delta power and decreased alpha2 power. No association of vascular damage was observed with alpha3 power. Moreover, the theta/alpha1 ratio could be a reliable index for the estimation of the individual extent of CV damage. On the other side, the group with moderate hippocampal atrophy showed the highest increase of alpha2 and alpha3 power. Moreover, when the amygdalar and hippocampal volumes are separately considered, within amygdalohippocampal complex (AHC), the increase of theta/gamma ratio is best associated with amygdalar atrophy whereas alpha3/alpha2 ratio is best associated with hippocampal atrophy. CVD and AHC damages are associated with specific EEG markers. So far, these EEG markers could have a prospective value in differential diagnosis between vascular and degenerative MCI.

Download Full-text

Topological alterations in older adults with temporal lobe epilepsy are distinct from amnestic mild cognitive impairment

Epilepsia ◽

10.1111/epi.16703 ◽

2020 ◽

Vol 61 (11) ◽

Author(s):

Erik Kaestner ◽

Anny Reyes ◽

Zhong Irene Wang ◽

Daniel L. Drane ◽

Vineet Punia ◽

...

Keyword(s):

Older Adults ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Amnestic Mild Cognitive Impairment

Download Full-text

Impaired Behavioral Pattern Separation in Refractory Temporal Lobe Epilepsy and Mild Cognitive Impairment

Journal of the International Neuropsychological Society ◽

10.1017/s1355617721000734 ◽

2021 ◽

pp. 1-13

Author(s):

Sanam J. Lalani ◽

Anny Reyes ◽

Erik Kaestner ◽

Shauna M. Stark ◽

Craig E.L. Stark ◽

...

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Episodic Memory ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Memory Impairment ◽

Verbal Learning ◽

Recognition Task ◽

Pattern Separation ◽

Hippocampal Damage

ABSTRACT Objective: Episodic memory impairment and hippocampal pathology are hallmark features of both temporal lobe epilepsy (TLE) and amnestic mild cognitive impairment (aMCI). Pattern separation (PS), which enables the distinction between similar but unique experiences, is thought to contribute to successful encoding and retrieval of episodic memories. Impaired PS has been proposed as a potential mechanism underling episodic memory impairment in aMCI, but this association is less established in TLE. In this study, we examined behavioral PS in patients with TLE and explored whether profiles of performance in TLE are similar to aMCI. Method: Patients with TLE, aMCI, and age-matched, healthy controls (HCs) completed a modified recognition task that relies on PS for the discrimination of highly similar lure items, the Mnemonic Similarity Task (MST). Group differences were evaluated and relationships between clinical characteristics, California Verbal Learning Test—Second Edition scores, and MST performance were tested in the TLE group. Results: Patients with TLE and aMCI demonstrated poorer PS performance relative to the HCs, but performance did not differ between the two patient groups. Neither the side of seizure focus nor having hippocampal sclerosis affected performance in TLE. However, TLE patients with clinically defined memory impairment showed the poorest performance. Conclusion: Memory performance on a task that relies on PS was disrupted to a similar extent in TLE and aMCI. The MST could provide a clinically useful tool for measuring hippocampus-dependent memory impairments in TLE and other neurological disorders associated with hippocampal damage.

Download Full-text