ENTORHINAL AND PERIRHINAL CORTICES ARE OFTEN DAMAGED IN MESIAL TEMPORAL LOBE EPILEPSY BUT SPARED IN PRIMARY GENERALIZED EPILEPSY
Abstract number :
3.150
Submission category :
Year :
2002
Submission ID :
1526
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Leonardo Bonilha, Eliane Kobayashi, Fernando Cendes, Li M. Li. Department of Neurology, UNICAMP, Campinas, SP, Brazil; Department of Neurology, UNICAMP, Campinas, SP, Brazil; Department of Neurology, UNICAMP, Campinas, SP, Brazil; Department of Neurology,
RATIONALE: Volumetric magnetic resonance imaging (MRI) has been successfully applied to evaluate the damage of the hippocampus and the amygdala in patients with temporal lobe epilepsy (TLE). A large network connects the cortical and sub cortical structures of the mesial portion of the temporal lobe. The extent of damage beyond the hippocampus in patients with temporal lobe epilepsy is not yet fully defined. The objective of this study is to quantitatively assess the mesial temporal lobe structures using high-resolution MR images in patients with chronic refractory TLE and primary generalized epilepsy.
METHODS: We studied 30 healthy subjects, 20 patients with unilateral drug-refractory temporal lobe epilepsy and 10 patients with primary generalized epilepsy. All subjects were scanned in a 2T-system (Elscint Prestige) with a T1 volumetric gradient echo sequence yielding a 1mm isotropic voxel (TR=22ms, TE=9ms, matrix=256x220, field of view = 25x25cm). Images underwent field non-homogeneity correction and linear stereotaxic transformation into a standard space. Structures of interest comprised of entorhinal cortex, perirhinal cortex, hippocampus and the amygdala. Segmentation was performed with simultaneous assessment of the structure in the coronal, sagittal and axial planes using anatomic landmarks based upon previous studies on histological architecture and MR imaging of the temporal lobe. Statistical significance was set at p[lt]0.05.
RESULTS: There was no difference between the volumes of the mesial temporal lobe of the patients with primary generalized epilepsy and the control subjects. Patients with right TLE showed reduction of the right hippocampus (p[lt]0.001), the right entorhinal cortex (p[lt]0.001), and the right perirhinal cortex (p[lt]0.001). Patients with left TLE showed significant reduction in the volume of the left hippocampus volume (p[lt]0.001), the left entorhinal cortex (p[lt]0.05), left perirhinal cortex (p[lt]0.001), right perirhinal cortex (p[lt]0.05), and left amygdala (p[lt]0.05).
CONCLUSIONS: These findings show evidence of damage that extends beyond the hippocampus in patients with temporal lobe epilepsy. This damage is greater in the regions with closer anatomical and functional connection to the hippocampus, and is restricted to patients with temporal lobe epilepsy, ie, it is not observed in patients with primary generalized epilepsy.
[Supported by: FAPESP, S[atilde]o Paulo, Brazil]