THESES
Structural changes of the temporal pole in hippocampal sclerosis: study based on the flair sequence and on volumetry by magnetic resonance (Abstract)* * Alterações estruturais do pólo temporal na esclerose hipocampal: estudo baseado na seqüência Flair e na volumetria por ressonância magnética (Resumo). Tese de Doutorado, Universidade Federal de São Paulo Escola Paulista de Medicina. Orientador: Nitamar Abdala. Co-orientador: Jacob Szejnfeld. . Thesis. São Paulo, 2007.
Henrique Carrete Jr** ** Address: DDI, EPM-UNIFESP, Rua Botucatu 740, 04023-900 São Paulo SP, Brasil (a/c Dr. Roberto Gomes Nogueira).
PURPOSE: To examine temporal pole (TP) signal and quantitative changes in temporal lobe epilepsy (TLE) patients with hippocampal sclerosis (HS) using coronal fluid-attenuated inversion-recovery (FLAIR) and volumetric MRI sequences and investigate the relationship between these changes and clinical parameters.
METHOD: We studied 120 patients with TLE and uni or bilateral HS detected by MRI and 30 age and sex-matched healthy control subjects. Coronal FLAIR images of TP were independently assessed by visual analysis, focusing gray/white matter demarcation loss and classifying this temporal pole signal abnormality (TPA) according to regional involvement in anteromedial and/or lateral. We have also analyzed quantitatively the volumes of the TP from patients and controls.
RESULTS: Sixty-one (51%) of 120 patients had left HS, 46 (38%) had right HS and 13 (11%) had bilateral HS. TPA was not present in any of controls. Ninety (75%) of 120 patients had associated TPA. TPA was always ipsilateral to unilateral HS and usually (70%) ipsilateral to the more affected hippocampus in bilateral cases. The HS side made difference regarding the presence of TPA, with a left side preference. The anteromedial zone of TP was affected in 27 (30%) out of 90 patients. In 63 (70%) patients the lateral zone were also affected. The presence of TPA was significantly associated with a younger age at onset of habitual seizures, but not with history of febrile seizure (FS) or other initial precipitating injury (IPI) in childhood, duration of epilepsy and seizure frequency. In patients with TPA there was a trend toward younger age at IPI as compared with patients without it. Quantitative analysis of TP demonstrated significant atrophy in 42 (35%) of 120 patients with HS. The TP volume was reduced meanly ipsilateral but also contralateral to HS in some cases. In patients with right HS, the mean volume of ipsilateral TP was 15% less than the mean volume of the corresponding lobe in controls, whereas in patients with left HS, the mean volume of ipsilateral TP was 13% less than the mean volume of the corresponding TP in controls. Patients with and without history of FS did not differed significantly in TP volume. The TP volume also failed to correlate with seizure frequency. The volume of TP was negatively correlated with duration of epilepsy, ipsilateral and contralateral to the HS. The degree of TP volume asymmetry index was not associated with the presence of TPA.
CONCLUSION: Three quarter of ELT patients with HS show TPA on coronal FLAIR images, always ipsilateral to HS in unilateral cases, with the anteromedial zone being affected in all. In bilateral HS, TPA is present ipsilateral to the more affected hippocampus in 70% of the cases. TPA occurring in 87% of left sided HS patients suggests a more widespread involvement when the dominant hemisphere is affected. There is an association between TPA and a younger age at seizure onset, whereas the patient age and the disease duration are negatively correlated with TP volume, ipsilateral and contralateral to HS.
Key words: hippocampal sclerosis, temporal lobe pole, MRI.
Publication Dates
-
Publication in this collection
11 Apr 2008 -
Date of issue
Sept 2007
