White matter abnormalities at a regional and voxel level in focal and generalized epilepsy: A systematic review and meta-analysis

Slinger, Geertruida; Sinke, Michel R.T.; Braun, Kees P.J.; Otte, Willem M.

doi:10.1016/j.nicl.2016.10.025

Cited by 55 publications

(68 citation statements)

References 66 publications

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“…16 Their results seem to be different from ours, which might be attributable to patient selection or the underlying causes of PNES. Most studies on DTI findings in various neurological and psychiatric disorders [17][18][19][20][21][22] showed reduced FA and/or increased MD, which were seen in our results, whereas increased FA are rarely reported. 23 The relationship and interpretation between brain dysfunction and DTI parameters are complex, and the discrepancy in FA results in PNES might reflect the heterogeneity and complexity of this disorder.…”

Section: Discussionsupporting

confidence: 64%

<p>Widely Impaired White Matter Integrity and Altered Structural Brain Networks in Psychogenic Non-Epileptic Seizures</p>

Sone¹,

Sato²,

Ota³

et al. 2019

NDT

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The underlying neural correlates of psychogenic non-epileptic seizures (PNES) are still unknown and their identification would be helpful for clinicians and patients. This study aimed to reveal details of white matter microstructure and alterations in brain structural networks in patients with PNES by using diffusion tensor imaging (DTI) and graph theoretical connectivity analysis. Methods: Seventeen patients with PNES and 26 age-and sex-matched healthy controls were enrolled. All participants underwent DTI on a 3.0-T MRI scanner, and fractional anisotropy (FA) and mean diffusivity (MD) maps were compared by tract-based spatial statistics. Additionally, the structural networks derived from DTI data were analyzed using graph theory and two different parcellation schemes. Results: Patients with PNES showed widespread decreases in FA and increases in MD, particularly in the deep white matter. In addition, graph theoretical analysis revealed impaired brain networks in PNES, including increased path length, decreased network efficiency, altered nodal topology, and reduced regional connectivity in the right posterior areas. Conclusion: We found widely impaired white matter integrity and impaired brain structural networks in Japanese patients with PNES. These findings contribute to the accumulation of evidence on PNES and may improve understanding of this condition.

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Section: Discussionsupporting

confidence: 64%

<p>Widely Impaired White Matter Integrity and Altered Structural Brain Networks in Psychogenic Non-Epileptic Seizures</p>

Sone¹,

Sato²,

Ota³

et al. 2019

NDT

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“…[13][14][15][16] Language impairment in RTLE has often been attributed to medication effects 17 or consequences of early seizure onset. 18,19 However, we propose that similar underlying patterns of neural abnormality in LTLE and RTLE 20,21 may provide a more direct explanation of language impairment.…”

Section: Introductionmentioning

confidence: 90%

Identifying the neural basis of a language‐impaired phenotype of temporal lobe epilepsy

et al. 2019

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Objective To identify neuroimaging and clinical biomarkers associated with a language‐impaired phenotype in refractory temporal lobe epilepsy (TLE). Methods Eighty‐five patients with TLE were characterized as language‐impaired (TLE‐LI) or non–language‐impaired (TLE‐NLI) based on comprehensive neuropsychological testing. Structural magnetic resonance imaging (MRI), diffusion tensor imaging, and functional MRI (fMRI) were obtained in patients and 47 healthy controls (HC). fMRI activations and cortical thickness were calculated within language regions of interest, and fractional anisotropy (FA) was calculated within deep white matter tracts associated with language. Analyses of variance were performed to test for differences among the groups in imaging measures. Receiver operator characteristic curves were used to determine how well different clinical versus imaging measures discriminated TLE‐LI from TLE‐NLI. Results TLE‐LI patients showed significantly less activation within left superior temporal cortex compared to HC and TLE‐NLI, regardless of side of seizure onset. TLE‐LI also showed decreased FA in the inferior longitudinal fasciculus and arcuate fasciculus compared to HC. Cortical thickness did not differ between groups in any region. A model that included language‐related fMRI activations within the superior temporal gyrus, age at onset, and demographic variables was the most predictive of language impairment (area under the curve = 0.80). Significance These findings demonstrate a unique imaging signature associated with a language‐impaired phenotype in TLE, characterized by functional and microstructural alterations within the language network. Reduced left superior temporal activation combined with compromise to language association tracts underlies this phenotype, extending our previous work on cognitive phenotypes that could have implications for treatment‐planning or cognitive progression in TLE.

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“…A recent imaging-based meta-analysis (Slinger et al, 2016) found that patients with TLE had pronounced and widespread white matter injury relative to other patient syndromes.…”

Section: Temporal Lobe Epilepsymentioning

confidence: 99%

White matter abnormalities across different epilepsy syndromes in adults: an ENIGMA Epilepsy study

Hatton¹,

Huynh²,

Bonilha³

et al. 2019

Preprint

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word count: 399 Body word count: 6127 (limit 6000) AbstractThe epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy.Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analyzed from 1,069 non-epileptic controls and 1,249 patients: temporal lobe epilepsy with hippocampal sclerosis (N=599), temporal lobe epilepsy with normal MRI (N=275), genetic generalized epilepsy (N=182) and nonlesional extratemporal epilepsy (N=193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fiber tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at p<0.001). Across "all epilepsies" lower fractional anisotropy was observed in most fiber tracts with small to medium effect sizes, especially in the corpus callosum, cingulum and external capsule. Less robust effects were seen with mean diffusivity. Syndrome-specific fractional anisotropy and mean diffusivity differences were most pronounced in patients with hippocampal sclerosis in the ipsilateral parahippocampal cingulum and external capsule, with smaller effects across most other tracts. Those with temporal lobe epilepsy and normal MRI showed a similar pattern of greater ipsilateral than contralateral abnormalities, but less marked than those in patients with hippocampal sclerosis. Patients with generalized and extratemporal epilepsies had pronounced differences in fractional anisotropy in the corpus callosum, corona radiata and external capsule, and in mean diffusivity of the anterior corona radiata. Earlier age of seizure onset and longer disease duration were associated with a greater extent of microstructural abnormalities in patients with hippocampal sclerosis. We demonstrate microstructural abnormalities across major association, commissural, and projection fibers in a large multicentre study of epilepsy.Overall, epilepsy patients showed white matter abnormalities in the corpus callosum, cingulum and external capsule, with differing severity across epilepsy syndromes. These data further define the spectrum of white matter abnormalities in common epilepsy syndromes, yielding new insights into pathological substrates that may be used to guide future therapeutic and genetic studies.

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White matter abnormalities at a regional and voxel level in focal and generalized epilepsy: A systematic review and meta-analysis

Cited by 55 publications

References 66 publications

<p>Widely Impaired White Matter Integrity and Altered Structural Brain Networks in Psychogenic Non-Epileptic Seizures</p>

<p>Widely Impaired White Matter Integrity and Altered Structural Brain Networks in Psychogenic Non-Epileptic Seizures</p>

Identifying the neural basis of a language‐impaired phenotype of temporal lobe epilepsy

White matter abnormalities across different epilepsy syndromes in adults: an ENIGMA Epilepsy study

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