Grey and white matter abnormalities in temporal lobe epilepsy with and without mesial temporal sclerosis

Scanlon, Cathy; Mueller, Susanne; Cheong, Ian; Hartig, Miriam; Weiner, Michael W.; Laxer, Kenneth D.

doi:10.1007/s00415-013-6974-3

Cited by 94 publications

(110 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Also it is important to note that their non-MTS group included 5/13 patients with bilateral seizure onset, thus lateralizing differences would likely be more difficult to observe than in other studies such as ours, where the non-MTS group contained solely unilateral TLE. Most recently, Scanlon et al (2013) examined FA abnormalities with tract-based spatial statistics and also found decreased FA in the corpus callosum, in addition to decreased FA in the ipsilateral anterior corona radiata. However, diffusivity measures were not compared in that study.…”

Section: Discussionmentioning

confidence: 99%

Quantitative relaxometry and diffusion MRI for lateralization in MTS and non-MTS temporal lobe epilepsy

et al. 2014

View full text Add to dashboard Cite

We developed novel methodology for investigating the use of quantitative relaxometry (T1, T2) and diffusion tensor imaging (DTI) for lateralization in temporal lobe epilepsy. Patients with mesial temporal sclerosis confirmed by pathology (N=8) and non-MTS unilateral temporal lobe epilepsy (N=6) were compared against healthy controls (N=19) using voxel-based analysis restricted to the anterior temporal lobes, and laterality indices for each MRI metric (T1, T2, fractional anisotropy (FA), mean diffusivity, axial and radial diffusivity) were computed based on the proportion of significant voxels on each side. The diffusivity metrics were the most lateralizing MRI metrics in MTS and non-MTS subsets, with significant differences also seen with FA, T1 and T2. Patient-specific multi-modal laterality indices were also computed and were shown to clearly separate the left-onset and right-onset patients. Marked differences between leftonset and right-onset patients were also observed, with left-onset patients exhibiting stronger laterality indices. Finally, neocortical abnormalities were found to be more common in the non-MTS patients. These preliminary results on a small sample size support the further investigation of quantitative MRI and multi-modal image analysis in clinical determination of seizure onset.The presence of more neocortical abnormalities in the non-MTS group suggests a role in seizure onset or propagation and motivates the investigation of more sensitive histopathological analysis to detect and delineate potentially subtle neocortical pathology.

show abstract

Section: Discussionmentioning

confidence: 99%

Quantitative relaxometry and diffusion MRI for lateralization in MTS and non-MTS temporal lobe epilepsy

et al. 2014

View full text Add to dashboard Cite

show abstract

“…TBSS can reduce the effects of local misregistrations by projecting all FA voxels onto the nearest location on a "skeleton" approximating WM tract center [9] [12] [13]. So TBSS has become a kind of popular software to study DTI, and has been used in some studies of various diseases, such as stroke [14], Parkinson [15], epilepsy [16], multiple sclerosis [17], traumatic brain injury [18], schizophrenia [19] and so on. Also some studies of cognitive disorders used TBSS, included mild cognitive impairment (MCI) and AD [9] [20].…”

Section: Introductionmentioning

confidence: 99%

White Matter Changes in Alzheimer’s Disease Revealed by Diffusion Tensor Imaging with TBSS

Chen¹,

Wang²,

Yao³

et al. 2015

WJNS

View full text Add to dashboard Cite

Alzheimer's disease (AD) is a progressive, neurodegenerative disorder characterized by impairments in multiple cognitive domains and it is hard to diagnose in early stage because it's not easy to recognize and develop slowly. In this study, we try to evaluate the difference of white matter between AD and health volunteers using diffusion tensor imaging (DTI) and try to provide some evidence for diagnose AD in early stage. Twelve elderly Chinese patients with AD and twelve healthy volunteers were recruited and underwent DTI. The raw diffusion data were dealt with the toolkit of FSL image post-processing. Fractional anisotrogy (FA) data were then carried out by using tract-based spatial statistics (TBSS). The result showed that the FA of cingulum, hippocampus, corticospinal tract, and inferior fronto-occipital fasciculus significantly reduced in AD patients than that of volunteers. This indicated that the integrity of white matter tracts in these regions with AD was disturbed. On the other hand, the FA of other encephalic regions had no discrepancy compared with that of healthy volunteers. FA values were found reduced significantly in AD patients, especially in the posterior of the brain. These findings may provide image methods to diagnose patients with early stage of AD.

show abstract

“…Beyond the volumetric studies there have been numerous reports based on diffusion imaging in adult temporal lobe epilepsy patients in which bilateral WM alterations can usually be detected in the limbic and non-limbic areas with ipsilateral predominance [10][11][12][13][14][15][16]. These changes are more extensive in patients with mesiotemporal sclerosis than in the non-lesional group [11,18]. Although the underlying cause is not clear for such alterations, several possible theories exist.…”

Section: Discussionmentioning

confidence: 99%

“…It is well known that structural abnormalities associated with MTLE-HS involve not only the hippocampus and the structures of the limbic system [4][5][6][7], but also the bilateral white matter (WM) with ipsilateral predominance [8][9][10][11][12][13][14][15][16][17]. It might be hypothesized that neuronal dysfunction/loss in the sclerotic hippocampus causes damage to WM structures connected to the epileptic foci due to the excitotoxic effects of the spreading epileptogenic activity which then induces microstructural abnormalities far away from the seizure focus [8,18]. Over the last years, diffusion-weighted imaging (DWI) was established as a useful tool to measure microstructural changes of the brain tissue in a variety of neurological diseases [19,20], including epilepsy [21].…”

Section: Introductionmentioning

confidence: 99%

Age at onset and seizure frequency affect white matter diffusion coefficient in patients with mesial temporal lobe epilepsy

Nagy

Horváth

Perlaki

et al. 2016

Epilepsy & Behavior

View full text Add to dashboard Cite

SummaryIn mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), structural abnormalities are present not only in the hippocampus, but also in the white matter with ipsilateral predominance. Although the timing of epilepsy onset is commonly associated with clinical and semiological dissimilarities, limited data exist regarding white matter diffusion changes with respect to age at epilepsy onset. The aim of this study was to investigate diffusion changes in the white matter of unilateral MTLE-HS patients with respect to clinical parameters and to compare them to an age-and sex matched healthy control group. Apparent diffusion coefficients (ADCs) were derived using mono-exponential approaches from 22 (11 early and 11 late age at onset) unilateral MTLE-HS patients and 22 age-and sex matched control subjects after acquiring diffusion-weighted images on a 3T MRI system. Data were analyzed using two-tailed t-tests and multiple linear regression models. In the early onset MTLE-HS group ADC was significantly elevated in the ipsilateral hemispheric (p=0.04) and temporal lobe white matter (p=0.01) compared to controls. These differences were not detectable in late onset MTLE-HS patients. ADC of the early onset MTLE-HS group was negatively related to age at epilepsy onset in the ipsilateral hemispheric white matter (p=0.03) and the uncinate fasciculus (p=0.03), while in late onset patients ADC was no longer dependent on age at epilepsy onset itself, but rather on the seizure frequency in the ipsilateral uncinate fasciculus (p=0.03). Such diffusivity pattern has been associated with chronic white matter degeneration, reflecting myelin loss and higher extracellular volume which are more pronounced in the fronto-temporal regions and also depends on clinical features. In the early onset group, the timing of epilepsy seems to be the major cause of white matter abnormalities while in late onset disease it has a secondary role in provoking diffusion changes.

show abstract

Grey and white matter abnormalities in temporal lobe epilepsy with and without mesial temporal sclerosis

Cited by 94 publications

References 30 publications

Quantitative relaxometry and diffusion MRI for lateralization in MTS and non-MTS temporal lobe epilepsy

Quantitative relaxometry and diffusion MRI for lateralization in MTS and non-MTS temporal lobe epilepsy

White Matter Changes in Alzheimer’s Disease Revealed by Diffusion Tensor Imaging with TBSS

Age at onset and seizure frequency affect white matter diffusion coefficient in patients with mesial temporal lobe epilepsy

Contact Info

Product

Resources

About