Relevance of Temporal Lobe White Matter Changes in Hippocampal Sclerosis

Meiners, Linda C.; Witkamp, T. D.; Kort, G. A. P. de; Huffelen, A.C. van; Graaf, Yolanda van der; Jansen, Gerard H.; Grond, Jeroen van der; Veelen, C.W.M. van

doi:10.1097/00004424-199901000-00006

Cited by 76 publications

(94 citation statements)

References 24 publications

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“…It was previously suggested that if there is hippocampal neuronal damage, it will cause ipsilateral fornix and mammilary body atrophy as a result of transneuronal degeneration 7 . Adjacent parahippocampal gyrus white matter (PHGWM) reduction 1,5,8,9 can be another associated finding (Figs 6 and 10) and is thought to be the cause of recurrent seizures after the first surgery (10-20%) 10 , as reported in previous studies. These patients were submitted to a new surgical intervention for extension of mesial ressected areas, with good results in most of the cases 11,12 .…”

supporting

confidence: 63%

Analysis of parahippocampal gyrus in 115 patients with hippocampal sclerosis

Ferreira

Oliveira

Amaral

et al. 2003

Arq. Neuro-Psiquiatr.

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-Purpose: Analysis of the parahippocampal gyrus (PHG) involvement in 115 patients with hippocampal sclerosis (HS) by MR imaging. The simultaneous occurrence of ipsilateral fornix (F) and mamillary body (MB) volume loss was checked also. These findings were correlated with the side of hippocampal involvement, the sex, patient´s age, and the symptoms onset. Method: The MR images of 115 patients with HS were studied retrospectively. All the examinations were performed on 1.5 T units (SIGNA, GE, Milwaukee, WI) and included high resolution coronal T2-weighted images (3 mm thickness, 0.6 mm gap). Results: The patient's age ranged between 3.5 and 80 years (mean 34.1); 62 (53.9%) were female and 53 (46.1%) were male. There were HS on the left side in 53 (46.0%), on the right side in 51 (44.3%), and bilateral in 11 (9.7%). In 43 (37.3%) cases there were ipsilateral PHG volume loss and signal hyper intensity on T2-weighted imaging. In 29 (25.2%) cases there were ipsilateral fornix volume loss and in 10 (34.5%) of this there were also ipsilateral MB changes. In abnormal PHG, 23 (53.4%) were on the left side, 17 (39.5%) were on the right side, and 3 (7.1%) were bilateral. There were fornix changes in 15 (34.8%) cases and MB volume loss in 5 (11.6%) cases. Pertinent clinical data were obtained in only 18 (41.8%) of the PHG lesion cases and 11 (61.1%) of these patients had epileptic attacks for more than 20 years before the examination. Conclusion: PHG involvement must be investigated in patients with HS and we suggest that the term mesial temporal sclerosis should be used only if there are also changes at this anatomical site.KEY WORDS: hippocampal sclerosis, epilepsy, MRI, parahippocampal gyrus.Análise do giro para-hipocampal em pacientes com esclerose hipocampal: estudo de 115 casos Análise do giro para-hipocampal em pacientes com esclerose hipocampal: estudo de 115 casos Análise do giro para-hipocampal em pacientes com esclerose hipocampal: estudo de 115 casos Análise do giro para-hipocampal em pacientes com esclerose hipocampal: estudo de 115 casos Análise do giro para-hipocampal em pacientes com esclerose hipocampal: estudo de 115 casos RESUMO -Objetivo: Analisar o envolvimento do giro para-hipocampal (GPH) em 115 pacientes com esclerose hipocampal (EH) à RM. Estudou-se a porcentagem dos casos com redução volumétrica do fórnix (F) e corpo mamilar (CM) ipsilaterais, lado acometido, sexo, idade e tempo de convulsão. Método: Estudo retrospectivo de 115 casos retirados do nosso arquivo. Foram realizados cortes coronais STIR (3mm de espessura com 0,6mm de espaçamento) em aparelhos GE, Signa Horizon, LX e CVI, 1,5T. Resultados: Nos 115 casos estudados, a idade dos pacientes variava entre 3,5 e 80 anos (média 34,1 anos); 62(53,9%) eram mulheres e 53(46,1%) eram homens; 53(46,0%) à esquerda, 51(44,3%) à direita e 11(9,7%) bilaterais; 43(37,3%) apresentavam GPH com dimensões reduzidas e hipersinal ipsilateral, 29(25,2%) fornix reduzido ipsilateralmente e destes, 10(34,5%) tinham CM alterado ipsilateral. Dos GPH alterado...

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supporting

confidence: 63%

Analysis of parahippocampal gyrus in 115 patients with hippocampal sclerosis

Ferreira

Oliveira

Amaral

et al. 2003

Arq. Neuro-Psiquiatr.

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“…This is in line with the literature, which reports that temporopolar blurring is present in 32‐66% of adults with TLE and HS39 and in 57% of children 42. It has previously been postulated to be caused by vasculometabolic changes,43 cortical dysplasia,44 inflammatory changes,45 increased perivascular spaces, abnormal water content,46 widespread gliosis45 as well as myelin loss 45. A recent study by Garbelli and colleagues relating histopathology to high‐field imaging carefully attempted to disentangle these factors and found that blurring was associated with axonal degeneration and reduced axonal numbers in the white matter 39.…”

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confidence: 99%

Multimodal computational neocortical anatomy in pediatric hippocampal sclerosis

Adler

Blackwood

Northam

et al. 2018

Ann Clin Transl Neurol

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ObjectiveIn contrast to adult cohorts, neocortical changes in epileptic children with hippocampal damage are not well characterized. Here, we mapped multimodal neocortical markers of epilepsy‐related structural compromise in a pediatric cohort of temporal lobe epilepsy and explored how they relate to clinical factors.MethodsWe measured cortical thickness, gray–white matter intensity contrast and intracortical FLAIR intensity in 22 patients with hippocampal sclerosis (HS) and 30 controls. Surface‐based linear models assessed between‐group differences in morphological and MR signal intensity markers. Structural integrity of the hippocampus was measured by quantifying atrophy and FLAIR patterns. Linear models were used to evaluate the relationships between hippocampal and neocortical MRI markers and clinical factors.ResultsIn the hippocampus, patients demonstrated ipsilateral atrophy and bilateral FLAIR hyperintensity. In the neocortex, patients showed FLAIR signal hyperintensities and gray–white matter boundary blurring in the ipsilesional mesial and lateral temporal neocortex. In contrast, cortical thinning was minimal and restricted to a small area of the ipsilesional temporal pole. Furthermore, patients with a history of febrile convulsions demonstrated more pronounced FLAIR hyperintensity in the ipsilesional temporal neocortex.InterpretationPediatric HS patients do not yet demonstrate the widespread cortical thinning present in adult cohorts, which may reflect consequences of a protracted disease process. However, pronounced temporal neocortical FLAIR hyperintensity and blurring of the gray–white matter boundary are already detectable, suggesting that alterations in MR signal intensities may reflect a different underlying pathophysiology that is detectable earlier in the disease and more pervasive in patients with a history of febrile convulsions.

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“…Several studies have clearly highlighted the occurrence of histological [Bothwell et al, 2001;Choi et al, 1999;Meiners et al, 1999;Mitchell et al, 1999], morphological [Jutila et al, 2001;Moran et al, 2001], and metabolic [Rubin et al, 1995;Ryvlin et al, 1998;Semah et al, 1995] changes in the anterior part of the temporal lobe in TLE. Electrophysiological [Chabardes et al, 2005] and perfusion studies using single photon emission computed tomography [Weder et al, 2006] have demonstrated the early involvement of the temporal pole in the genesis of seizures.…”

Section: Introductionmentioning

confidence: 99%

“…There have been also observations of MRI signal changes, most notably an increase in T2-weighted signal intensity in the WM of the anterior temporal lobe, which is sometimes associated with hypointense signal on T1-weighted images [Mitchell et al, 1999]. These abnormalities have been referred to as WM blurring and loss of the GM-WM demarcation, respectively [Meiners et al, 1994[Meiners et al, , 1999Mitchell et al, 1999;Ryvlin et al, 1991].…”

Section: Introductionmentioning

confidence: 99%

Temporal lobe epilepsy: Differential pattern of damage in temporopolar cortex and white matter

Sankar

Bernasconi

Kim

et al. 2008

Human Brain Mapping

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Our purpose was to quantify structural changes of the temporopolar cortex (TPC) and its white matter (TPWM) in temporal lobe epilepsy (TLE) using MRI volumetry and texture analysis. We studied 23 patients with hippocampal atrophy, and 20 healthy controls. Gradient magnitude and entropy were calculated to model signal intensity blurring on T1-MRI. Two observers assessed signal changes and atrophy visually. Compared to controls, TLE patients had a decrease in TPC and TPWM volume ipsilateral to the seizure focus. The gradient magnitude and entropy were decreased ipsilateral to the focus only in TPWM, indicating blurring of this compartment. Eighty-seven percent of TLE patients had at least one volumetric or textural abnormality. Although sensitivity of visual and quantitative assessment of TPC atrophy was comparable (43 and 39%), specificity was higher for volumetry (54% vs. 95%). Compared to visual analysis of signal changes in TPWM on T1-MRI, texture metrics had higher sensitivity (65% vs. 17%) and specificity (100% vs. 69%). The proportion of patients with blurring of TPWM as determined by texture analysis was higher than that seen on visual inspection of T2 images (78% vs. 43%). We found no clear association between volumetric or textural changes of TPC and TPWM and outcome after surgery. Structural changes of the anatomically distinct TPC and TPWM are found ipsilateral to the seizure focus in the majority of TLE patients with hippocampal sclerosis. MRI post-processing allows dissociating different pathological tissue characteristics and shows that atrophy involves gray and white matter, whereas blurring is confined to white matter. Hum Brain

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Relevance of Temporal Lobe White Matter Changes in Hippocampal Sclerosis

Abstract: ACWMp and GWDL can improve the visual diagnosis of hippocampal sclerosis, particularly in patients with no or restricted hippocampal abnormalities. These results suggest that loss of myelin may be the underlying cause of GWDL in association with hippocampal sclerosis.

Cited by 76 publications

References 24 publications

Analysis of parahippocampal gyrus in 115 patients with hippocampal sclerosis

Analysis of parahippocampal gyrus in 115 patients with hippocampal sclerosis

Multimodal computational neocortical anatomy in pediatric hippocampal sclerosis

Temporal lobe epilepsy: Differential pattern of damage in temporopolar cortex and white matter

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