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Parlak S, Coban G, Gumeler E, Karakaya J, Soylemezoglu F, Tezer I, Bilginer B, Saygi S, Oguz KK. Reduced myelin in patients with isolated hippocampal sclerosis as assessed by SyMRI. Neuroradiology 2021; 64:99-107. [PMID: 34611716 PMCID: PMC8492040 DOI: 10.1007/s00234-021-02824-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/25/2021] [Indexed: 02/05/2023]
Abstract
Purpose Synthetic MRI (SyMRI) enables to quantify brain tissue and morphometry. We aimed to investigate the WM and myelin alterations in patients with unilateral hippocampal sclerosis (HS) with SyMRI. Methods Adult patients with isolated unilateral HS and age-matched control subjects (CSs) were included in this study. The SyMRI sequence QRAPMASTER in the coronal plane perpendicular to the hippocampi was obtained from the whole brain. Automatic segmentation of the whole brain was processed by SyMRI Diagnostic software (Version 11.2). Two neuroradiologists also performed quantitative analyses independently from symmetrical 14 ROIs placed in temporal and extratemporal WM, hippocampi, and amygdalae in both hemispheres. Results Sixteen patients (F/M = 6/10, mean age = 32.5 ± 11.3 years; right/left HS: 8/8) and 10 CSs (F/M = 5/5, mean age = 30.7 ± 7 years) were included. Left HS patients had significantly lower myelin and WM volumes than CSs (p < .05). Myelin was reduced significantly in the ipsilateral temporal lobe of patients than CSs, greater in left HS (p < .05). Histopathological examination including luxol fast blue stain also revealed myelin pallor in all of 6 patients who were operated. Ipsilateral temporal pole and sub-insular WM had significantly reduced myelin than the corresponding contralateral regions in patients (p < .05). No significant difference was found in WM values. GM values were significantly lower in hippocampi in patients than CSs (p < .05). Conclusion SyMRI revealed myelin reduction in the ipsilateral temporal lobe and sub-insular WM of patients with HS. Whether this finding correlates with electrophysiological features and SyMRI could serve as lateralization of temporal lobe epilepsy need to be investigated. Supplementary Information The online version contains supplementary material available at 10.1007/s00234-021-02824-6.
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Affiliation(s)
- Safak Parlak
- Department of Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
| | - Gokcen Coban
- Department of Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Ekim Gumeler
- Department of Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Jale Karakaya
- Department of Biostatistics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Figen Soylemezoglu
- Department of Pathology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Irsel Tezer
- Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Burcak Bilginer
- Department of Neurosurgery, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Serap Saygi
- Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Kader K Oguz
- Department of Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
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Buksakowska I, Szabó N, Martinkovič L, Faragó P, Király A, Vrána J, Kincses ZT, Meluzín J, Šulc V, Kynčl M, Roček M, Tichý M, Charvát F, Hořínek D, Marusič P. Distinctive Patterns of Seizure-Related White Matter Alterations in Right and Left Temporal Lobe Epilepsy. Front Neurol 2019; 10:986. [PMID: 31632330 PMCID: PMC6779711 DOI: 10.3389/fneur.2019.00986] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/29/2019] [Indexed: 12/14/2022] Open
Abstract
Background: We hypothesized that right and left temporal lobe epilepsy (RTLE and LTLE, respectively) have distinctive spatial patterns of white matter (WM) changes that can be differentiated and interpreted with the use of multiple diffusion parameters. We compared the global microstructure of fiber bundles with regard to WM alterations in both RTLE and LTLE, addressing some of the methodological issues of previous studies. Methods: Diffusion tensor imaging data from 17 patients with RTLE (age: 40.7 ± 10.4), 15 patients with LTLE (age: 37.3 ± 10.4), and 15 controls (age: 34.8 ± 11.2) were used in the study. WM integrity was quantified by fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity (LD), and radial diffusivity (RD). The diffusion parameters were compared between the groups in tracts representing the core of the fiber bundles. The volumes of hippocampi and amygdala were subsequently compared across the groups, while the data were adjusted for the effect of hippocampal sclerosis. Results: Significantly reduced FA and increased MD, LD, and RD were found bilaterally over widespread brain regions in RTLE. An increase in MD and RD values was observed in widespread WM fiber bundles ipsilaterally in LTLE, largely overlapping with regions where FA was lower, while no increase in LD was observed. We also found a difference between the LTLE and RTLE groups for the right hippocampal volume (with and without adjustment for HS), whereas no significant volume differences were found between patients and controls. Conclusions: It appears that patients with RTLE exhibit a more widespread pattern of WM alterations that extend far beyond the temporal lobe in both ipsilateral and contralateral hemisphere; furthermore, these changes seem to reflect more severe damage related to chronic degeneration. Conversely, more restrained changes in the LTLE may imply a pattern of less severe axonal damage, more restricted to ipsilateral hemisphere. Comprehensive finding of more prominent hippocampal atrophy in the RTLE raises an interesting issue of seizure-induced implications on gray matter and WM microstructure that may not necessarily mean a straightforward causal relationship. Further correlations of diffusion-derived metrics with neuropsychological and functional imaging measures may provide complementary information on underlying WM abnormalities with regard to functional hemispheric specialization.
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Affiliation(s)
- Irena Buksakowska
- Department of Radiology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Nikoletta Szabó
- Department of Neurology, Faculty of General Medicine, University of Szeged, Szeged, Hungary
| | - Lukáš Martinkovič
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Péter Faragó
- Department of Neurology, Faculty of General Medicine, University of Szeged, Szeged, Hungary
| | - András Király
- Department of Neurology, Faculty of General Medicine, University of Szeged, Szeged, Hungary
| | - Jiří Vrána
- Department of Radiodiagnostics, University Central Military Hospital, Prague, Czechia
| | - Zsigmond Tamás Kincses
- Department of Neurology, Faculty of General Medicine, University of Szeged, Szeged, Hungary
| | - Jan Meluzín
- Department of Radiology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Vlastimil Šulc
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Martin Kynčl
- Department of Radiology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Miloslav Roček
- Department of Radiology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Michal Tichý
- Department of Neurosurgery, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - František Charvát
- Department of Radiodiagnostics, University Central Military Hospital, Prague, Czechia
| | - Daniel Hořínek
- Department of Neurosurgery, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Petr Marusič
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
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Tsuda K, Tsuji T, Ishida T, Takahashi S, Yamada S, Ohoshi Y, Terada M, Shinosaki K, Ukai S. Widespread abnormalities in white matter integrity and their relationship with duration of illness in temporal lobe epilepsy. Epilepsia Open 2018; 3:247-254. [PMID: 29881803 PMCID: PMC5983132 DOI: 10.1002/epi4.12222] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2018] [Indexed: 11/11/2022] Open
Abstract
Objective Elucidation of abnormal connections throughout the whole brain is necessary to understand temporal lobe epilepsy (TLE). We examined abnormalities in whole‐brain white matter integrity and their relationship with duration of illness in patients with TLE. Methods The subjects were 15 patients with TLE and 17 healthy controls. Mean duration of illness in the TLE group was 21.6 years. Tract‐based spatial statistics (TBSS) were used for diffusion tensor imaging (DTI) analysis. Four diffusion tensor metrics, that is, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated and then examined for differences between the TLE and healthy control groups. We also examined for correlations between DTI parameters and duration of illness in the TLE group. Results In the TLE group, compared with the healthy control group, FA was reduced, and MD and RD were increased, not only in the limbic and temporal lobe regions and their directly connecting regions in both hemispheres, but also in remote white matter regions. Duration of illness showed a significant negative correlation with mean whole‐brain FA and a significant positive correlation with both mean whole‐brain MD and RD. Brain regions showing correlation between disease duration and DTI metrics also extended to the limbic area and its connecting regions, and to remote white matter regions. Significance The results of this study suggest that widespread abnormalities in white matter integrity in patients with TLE are associated with long‐term disease.
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Affiliation(s)
- Kumi Tsuda
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan.,Mizuma Hospital Osaka Japan
| | - Tomikimi Tsuji
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan
| | - Takuya Ishida
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan
| | - Shun Takahashi
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan
| | - Shinichi Yamada
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan
| | - Yuji Ohoshi
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan
| | | | - Kazuhiro Shinosaki
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan.,Asakayama General Hospital Osaka Japan
| | - Satoshi Ukai
- Department of Neuropsychiatry Wakayama Medical University Wakayama Japan
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Yuce I, Kantarci M, Keles P, Yesilyurt H, Ogul H, Yuce H, Eren S. Diffusion tensor imaging of the hippocampus in chronic cigarette smokers. Eur J Radiol 2016; 85:1538-44. [PMID: 27501886 DOI: 10.1016/j.ejrad.2016.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 05/29/2016] [Accepted: 06/05/2016] [Indexed: 11/18/2022]
Abstract
PURPOSE Previous studies have demonstrated neuronal dis-integrity in chronic smokers using diffusion tensor imaging (DTI). However, assessment of hippocampal DTI has not been performed in this group. The purpose of this study was to investigate the hippocampal integrity in chronic smokers and non-smokers and to compare this to memory performance. METHODS We used in vivo DTI to measure the differences in hippocampal integrity between 88 chronic smoker and 88 non-smoking subjects. DTI was performed on a 3T scanner. We administered a verbal learning test to assess new verbal learning capabilities. The immediate recall (IR) was administered immediately after test procedure and delayed recall (DR) after 15min. RESULTS Mean values of fractional anisotropy (FA) for non-smokers and smokers were 0.46 and 0.40, respectively (p<0.05). Mean IR word number for non-smokers and smokers was 11.6, 9.04, respectively (p<0.05). The mean word number of DR for non-smokers and smokers was 10.2, 7.2, respectively (p<0.05). CONCLUSIONS This is the first study of hippocampal DTI assessment in the chronic smokers. We found that decreased hippocampal FA associated with neuronal dis-integrity and worse memory performance in chronic smokers than non-smokers. We also found a low positive correlation hippocampal FA values with memory performance in nonsmoking group.
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Affiliation(s)
- Ihsan Yuce
- Ataturk University, School of Medicine, Department of Radiology, Erzurum, Turkey.
| | - Mecit Kantarci
- Ataturk University, School of Medicine, Department of Radiology, Erzurum, Turkey
| | - Papatya Keles
- Ataturk University, School of Medicine, Department of Anatomy, Erzurum, Turkey
| | - Hakki Yesilyurt
- Ataturk University, School of Medicine, Department of Anatomy, Erzurum, Turkey
| | - Hayri Ogul
- Ataturk University, School of Medicine, Department of Radiology, Erzurum, Turkey
| | - Hatice Yuce
- Ataturk University, School of Medicine, Department of Psychiatry, Erzurum, Turkey
| | - Suat Eren
- Ataturk University, School of Medicine, Department of Radiology, Erzurum, Turkey
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Sex, epilepsy, and epigenetics. Neurobiol Dis 2014; 72 Pt B:210-6. [PMID: 24998474 DOI: 10.1016/j.nbd.2014.06.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/19/2014] [Accepted: 06/24/2014] [Indexed: 02/05/2023] Open
Abstract
Epilepsy refers to a heterogeneous group of disorders that are associated with a wide range of pathogenic mechanisms, seizure manifestations, comorbidity profiles, and therapeutic responses. These characteristics are all influenced quite significantly by sex. As with other conditions exhibiting such patterns, sex differences in epilepsy are thought to arise-at the most fundamental level-from the "organizational" and "activational" effects of sex hormones as well as from the direct actions of the sex chromosomes. However, our understanding of the specific molecular, cellular, and network level processes responsible for mediating sex differences in epilepsy remains limited. Because increasing evidence suggests that epigenetic mechanisms are involved both in epilepsy and in brain sexual dimorphism, we make the case here that analyzing epigenetic regulation will provide novel insights into the basis for sex differences in epilepsy.
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Santana MTCG, Jackowski AP, Britto FDS, Sandim GB, Caboclo LOSF, Centeno RS, Carrete H, Yacubian EMT. Gender and hemispheric differences in temporal lobe epilepsy: A VBM study. Seizure 2014; 23:274-9. [DOI: 10.1016/j.seizure.2013.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 12/10/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022] Open
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Abstract
Limbic epilepsy refers to a condition that consists of epileptic seizures that originate in or preferentially involve the limbic system. The majority of cases are medically refractory, necessitating surgical resection when possible. However, even resection of structures thought to be responsible for seizure generation may not leave a patient seizure free. While mesial temporal lobe limbic structures are centrally involved, there is growing evidence that the epileptogenic network consists of a broader area, involving structures outside of the temporal lobe and the limbic system. Information on structural, functional, and metabolic connectivity in patients with limbic epilepsy is available from a large body of studies employing methods such as MRI, EEG, MEG, fMRI, PET, and SPECT scanning, implicating the involvement of various brain regions in the epileptogenic network. To date, there are no consistent and conclusive findings to define the exact boundaries of this network, but it is possible that in the future studies of network connectivity in the individual patient may allow more tailored treatment and prognosis in terms of surgical resection.
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Winston GP, Stretton J, Sidhu MK, Symms MR, Duncan JS. Progressive white matter changes following anterior temporal lobe resection for epilepsy. NEUROIMAGE-CLINICAL 2013; 4:190-200. [PMID: 24392306 PMCID: PMC3879413 DOI: 10.1016/j.nicl.2013.12.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 12/01/2013] [Accepted: 12/05/2013] [Indexed: 11/01/2022]
Abstract
Anterior temporal lobe resection (ATLR) is an effective treatment for refractory temporal lobe epilepsy (TLE). Widespread abnormalities in diffusion parameters involving the ipsilateral temporal lobe white matter and extending into extratemporal white matter have been shown in cross-sectional studies in TLE. However longitudinal changes following surgery have been less well addressed. We systematically assess diffusion changes in white matter in patients with TLE in comparison to controls before surgery and look at the longitudinal changes following ATLR at two timepoints (3-4 months, 12 months) using a whole brain approach. We find predominantly unilateral baseline changes in temporal and extratemporal structures compatible with altered myelination (reduced fractional anisotropy, increased mean and radial diffusivity). Following surgery, these changes progress in efferent tracts from the resected temporal lobe compatible with Wallerian degeneration. However more superiorly in the corona radiata, internal and external capsules and nearby tracts, changes compatible with plasticity are observed (increased fractional anisotropy and axial diffusivity, reduced radial diffusivity). There is little progression between 3-4 months and 12 months following surgery in patients with left TLE, but the changes become more widespread in patients with right TLE suggesting that plasticity occurs more slowly in this population. The neuropsychological correlates of such plasticity should be explored further.
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Affiliation(s)
- Gavin P Winston
- Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, England, UK
| | - Jason Stretton
- Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, England, UK
| | - Meneka K Sidhu
- Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, England, UK
| | - Mark R Symms
- Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, England, UK
| | - John S Duncan
- Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, England, UK
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