Temporal Lobe Epilepsy with Amygdala Enlargement: A Morphologic and Functional Study.

From the Radioisotope Research Center, Kyoto University, Kyoto, Japan (ST)
Journal of neuroimaging: official journal of the American Society of Neuroimaging (Impact Factor: 1.82). 02/2012; DOI: 10.1111/j.1552-6569.2011.00694.x
Source: PubMed

ABSTRACT BACKGROUND AND PURPOSE: Temporal lobe epilepsy (TLE) with nontumoral amygdala enlargement (AE) has been reported to be a possible subtype of TLE without hippocampal sclerosis (HS). The purpose of this study was to clarify morphologic and functional characteristics of TLE with AE (TLE + AE). METHODS: We evaluated gray matter volume and cerebral glucose hypometabolism using magnetic resonance imaging (MRI) voxel-based morphometry (VBM) and voxel-based statistical analysis of [(18) F]-fluorodeoxyglucose positron emission tomography (FDG-PET) images in 9 patients with TLE + AE as compared with controls. For VBM analysis, we recruited 30 age- and sex-matched healthy volunteers as controls. For the comparison of FDG-PET analysis, 9 patients with definite mesial TLE with HS (MTLE + HS), and 16 age- and sex-matched healthy controls were recruited. RESULTS: In patients with TLE + AE, a significant increase in gray matter volume was found only in the affected amygdala, and no significant decrease in gray matter volume was detected. In addition, significant glucose hypometabolism was observed in the affected amygdala, whereas significant glucose hypometabolism in the hippocampus, a prominent feature of definite MTLE+HS, was not observed. CONCLUSIONS: TLE + AE is different from MTLE + HS from morphologic and functional points of view, and the enlarged amygdala per se is potentially an epileptic focus in patients with partial epilepsy. J Neuroimaging 2012;XX:1-9.

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    ABSTRACT: Background Some recent studies suggest that some imaging-negative temporal lobe epilepsy (TLE) had significant amygdala enlargement (AE). Contradictory data were also reported in previous studies regarding the association between AE and TLE. The present study was to investigate the clinical characters of a group of TLE with AE and compare the amygdala volume of the same patient before and after antiepileptic drugs treatment by a larger sample size.Methods This study recruited 33 mesial TLE patients with AE and 35 healthy volunteers. The clinical history, seizure semiology, electroencephalogram (EEG), fluorodeoxyglucose-positron emission tomography (FDG-PET) and amygdala volume were investigated. The amygdala volume were compared between ipsilateral and contralateral sides, TLE patients and 35 healthy controls, and patients at first and follow-up visit by 3.0 T MRI.ResultsAverage seizure onset age was 42.0 years (SD 14.3). All patients had complex partial seizures, fourteen had occasional generalized tonic-clonic seizures which often happened during sleep. Ninety percent patients suffered from anxiety or depression. Thirty percent patients had memory decline. Interictal epileptiform discharges appeared predominantly in the anterior or inferior temporal area ipsilateral to AE. Interictal FDG-PET showed regional glucose hypometabolism in the ipsilateral temporal lobe. No hippocampal sclerosis (HS) was suspected in all patients. 22 patients demonstrated good seizure control and significantly reduced volume of the enlarged amygdala after treatment (P¿<¿0.01). The other 11 patients showed initial response to treatment, followed by a gradual increase in seizure frequency over time, and no volume change of the enlarged amygdala after treatment.ConclusionsTLE with AE probably represents a distinct nosological and probably less homogeneous syndrome which is most likely a subtype of TLE without ipsilateral HS. The chronic and long lasting inflammatory processes or focal cortical dysplasia could lead to amygdala enlargement possibly.
    BMC Neurology 10/2014; 14(1):194. DOI:10.1186/s12883-014-0194-z · 2.49 Impact Factor
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    ABSTRACT: To quantitatively compare the diagnostic capability of double inversion-recovery (DIR) with F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) for detection of seizure focus laterality in temporal lobe epilepsy (TLE). This study was approved by the institutional review board, and written informed consent was obtained. Fifteen patients with TLE and 38 healthy volunteers were enrolled. All magnetic resonance (MR) images were acquired using a 3T-MRI system. Voxel-based analysis (VBA) was conducted for FDG-PET images and white matter segments of DIR images (DIR-WM) focused on the whole temporal lobe (TL) and the anterior part of the temporal lobe (ATL). Distribution of hypometabolic areas on FDG-PET and increased signal intensity areas on DIR-WM were evaluated, and their laterality was compared with clinically determined seizure focus laterality. Correct diagnostic rates of laterality were evaluated, and agreement between DIR-WM and FDG-PET was assessed using κ statistics. Increased signal intensity areas on DIR-WM were located at the vicinity of the hypometabolic areas on FDG-PET, especially in the ATL. Correct diagnostic rates of seizure focus laterality for DIR-WM (0.80 and 0.67 for the TL and the ATL, respectively) were slightly higher than those for FDG-PET (0.67 and 0.60 for the TL and the ATL, respectively). Agreement of laterality between DIR-WM and FDG-PET was substantial for the TL and almost perfect for the ATL (κ = 0.67 and 0.86, respectively). High agreement in localization between DIR-WM and FDG-PET and nearly equivalent detectability of them show us an additional role of MRI in TLE.
    Epilepsia 10/2013; 54(12). DOI:10.1111/epi.12396 · 4.58 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSEAmygdala enlargement (AE) has been reported as an epileptogenic focus in subtypes of temporal lobe epilepsy (TLE). The purpose of this study was to investigate the clinical, morphological, and pathological characteristics of AE. METHODS We retrospectively reviewed the clinical data and imaging findings of 23 TLE patients with ipsilateral AE. We performed morphological MR analyses using FreeSurfer and voxel-based morphometry (VBM) in 14 of the 23 patients and in 20 controls whose images were obtained by a 3.0-Tesla MRI. A pathological study was also performed in 2 patients who underwent operations. RESULTSAll patients became seizure free or shSowed dramatic improvement by medical therapy except for two. They received operations and their pathology revealed that both patients had cortical dysplasia in from the amygdala to the ipsilateral temporal pole. The FreeSurfer analysis showed a significant difference in the amygdala volumes between the affected and nonaffected sides. VBM revealed significant increases of gray matter volumes of the temporal pole on the side of AE in seven of the 14 patients with AE (50%). CONCLUSIONS Cortical dysplasia may be one of the pathological diagnoses in AE, and in some patients it may extend to the temporal pole.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 02/2014; DOI:10.1111/jon.12106 · 1.82 Impact Factor

Shigetoshi Takaya