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ABSTRACT: This study was conducted to determine the incidence of grey-white matter abnormalities (GWMAs) on magnetic resonance images (MRIs) in patients with hippocampal sclerosis (HS), to assess the inter-observer reliability of this finding, and to establish a possible relationship between GWMA and histopathological findings in the anterior part of the temporal lobe, as well as its other relation to clinical variables. We established a group of 55 patients with histologically proven HS. Three observers independently reviewed the MRIs to assess whether GWMA was present. Substantial independent inter-observer agreement was reached for 44 of the 55 patients (80%) (Fleiss' kappa 0.732; p<0.0001). GWMAs were present in 38% of patients (HS+GWMA). Focal cortical dysplasia (FCD) of type IIIa (ILAE classification) was present in 31% of patients. FCD type IIIa was present in 52.4% with HS+GWMA, and in 17.6% without GWMA (HS-GWMA) (p=0.007). We did not find any statistically significant differences in the postoperative outcomes between HS+GWMA and HS-GWMA. We did not find any statistically significant differences in the presence or absence of GWMA and FCD of the temporal pole in relation to the onset of epilepsy, the duration of epilepsy, or the presence of potential epileptogenic insults. GWMA in the anterior part of temporal lobe in patients with HS is a reliable assessment sign for observers who are experienced in evaluating the MRIs of epilepsy patients. The presence of GWMA is significantly associated with the presence of FCD type IIIa in these patients. The presence or absence of GWMA and FCD type IIIa does not influence the postoperative outcome of HS patients.
Epilepsy research 06/2012; · 2.48 Impact Factor
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ABSTRACT: To determine whether voxel-based morphometry (VBM) might contribute to the detection of cortical dysplasia within the temporal pole in patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE/HS).
Eighteen patients with intractable MTLE/HS and 30 sex- and age-matched healthy controls were included in the study. All of the patients fulfilled the diagnostic criteria for MTLE/HS and underwent anteromedial temporal resection. VBM without a modulation step was applied to the magnetic resonance (MR) images of the brain. Statistical parametric maps were used to compare structural characteristics such as gray matter concentration (GMC) within the temporal pole among patients and controls separately. The acquired data were then statistically analyzed to determine the congruency between visually inspected MR imaging (MRI) scans and VBM results in the detection of morphologic abnormalities in the temporal pole compared to postoperative histopathologic findings of cortical dysplasia.
Histopathologic examination revealed cortical dysplasia within the temporal pole in 11 patients. In detail, according to Palmini's classification, mild malformations of cortical development (mMCDs) were disclosed in three patients, focal cortical dysplasia (FCD) type Ia in three patients, and FCD type Ib in five patients. Some type of structural temporal pole abnormality was suggested by VBM in 14 patients and by visually inspected MRI scans in 11 patients. The results of VBM were in agreement with the presence/absence of cortical dysplasia in 13 patients (72.2%); this correspondence was significant (p = 0.047). In one case, VBM was false negative and in four cases it was false positive. There was congruence between the results of visual analysis and histologic proof in 55.6% of examined patients, which was not significant.
We found that VBM made a superior contribution to the detection of temporopolar structural malformations (cortical dysplasia) compared to visual inspection. The agreement with postoperative histopathologic proof was clearly significant for VBM results and nonsignificant for visual inspection.
Epilepsia 04/2012; 53(6):1004-12. · 3.96 Impact Factor
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ABSTRACT: The aim of this retrospective study was to analyze invasive EEG findings, histopathology, and postoperative outcomes in patients with MRI-negative, PET-positive temporal lobe epilepsy (TLE) (MRI-/PET+TLE) who had undergone epilepsy surgery. We identified 20 patients with MRI-/PET+TLE (8.4% of all patients with TLE who had undergone surgery; 11 men, 9 women). Of the 20 patients, 16 underwent invasive EEG. The temporal pole and hippocampus were involved in the seizure onset zone in 62.5% of the patients. We did not identify a lateral temporal or extratemporal seizure onset in any patient. Of the 20 patients, 17 had follow-up periods >1 year (mean follow-up=3.3 years). At the final follow-up, 70.6% patients were classified as Engel I, 5.8% of patients as Engel II, and 11.8% of patients as Engel III and IV (11.8%). Histopathological evaluation showed no structural pathology in any resected hippocampus in 58% of all evaluated temporal poles. The most common pathology of the temporal pole was focal cortical dysplasia type IA or IB. MRI-/PET+TLE should be delineated from other "nonlesional TLE." The ictal onset in these patients was in each case in the temporal pole or hippocampus, rather than in the lateral temporal neocortex. Standard surgery produced a good postoperative outcome, comparable to that for patients with lesional TLE. Histopathological findings were limited: the most common pathology was focal cortical dysplasia type I.
Epilepsy & Behavior 09/2011; 22(3):537-41. · 2.34 Impact Factor
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ABSTRACT: To perform a retrospective study to determine the incidence and lateralizing value of ictal dystonia in patients with temporal lobe epilepsy.
The study included 142 patients (76 males, 66 females) with temporal lobe epilepsy, aged from 19 to 58 years with an average age of 33.1 +/- 8.7 years. Overall, 454 seizures were analysed. The seizure onset zone was mesial in 112 patients (78.8%), and "non-mesial" in 30 patients (21.2%).
Ictal dystonia was present in 68 of the 142 patients (47.9%), and in 186 of 454 total seizures (40.9%). Upper limb dystonia was present in 94 seizures (50.5%) of 32 patients; hemidystonia in 84 seizures (45.2%) of 30 patients; and lower limb dystonia in eight seizures (4.3%) of six patients. For all cases, all types of ictal dystonia were contralateral to the seizure onset zone. Ictal dystonia was significantly more frequent in patients with a mesial seizure onset zone than in "non-mesial" patients (58.1% vs 7.7%; p < 0.001). Within the mesial group, ictal dystonia was significantly more frequent in patients with hippocampal sclerosis than in those patients with other lesions (66.1% vs 41.1%; p = 0.023).
Ictal dystonia in temporal lobe epilepsy is a reliable lateralizing ictal sign. During almost half of the seizures studied, ictal dystonia was present in the form of hemidystonia, and isolated involvement of the lower limbs also occurred. Combined data obtained from both noninvasive and invasive EEG showed that ictal dystonia tended to occur more often in mesial onset temporal lobe epilepsy, especially when hippocampal sclerosis was the epileptogenic lesion.
Epileptic disorders: international epilepsy journal with videotape 06/2010; 12(2):109-15. · 1.50 Impact Factor
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ABSTRACT: We tested the hypothesis that secondary generalized seizures (SGS) are not truly generalized and may involve selective regions.
The spread from focal to generalized seizures in temporal lobe epilepsy (TLE) was studied in 20 SGS recorded via stereo-EEG (SEEG) in 15 candidates for surgery. Electrodes were assigned to fronto-orbital, prefrontal, and temporal cortex, cingulate, hippocampus, and amygdala. The onset of SGS was ascertained by behavioral analysis of the video recordings. EEG recordings were evaluated using the rating scale developed by Blumenfeld [Blumenfeld H, Rivera M, McNally KA, Davis K, Spencer DD, Spencer SS. Ictal neocortical slowing in temporal lobe epilepsy. Neurology 2004;63:1015-21]. The seizure rating in each region was compared with the rating in the hippocampus.
Ranking significantly differed in the cingulate and fronto-orbital cortex; there was a trend toward significance in the prefrontal cortex. In these regions, slow activity dominated.
The onset of secondary generalization, when the head, face and all limbs are involved, does not implicate global cortical involvement.
Epilepsy & Behavior 04/2009; 15(2):235-9. · 2.34 Impact Factor
