1. Temporal lobe epilepsy: a combined study with high field (7T) Magnetic Resonance Imaging and optical and ultrastructural histopathology
- Author
-
GARBELLI, RITA, Milesi, G, MILESI, GLORIA, GARBELLI, RITA, Milesi, G, and MILESI, GLORIA
- Abstract
Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy with 60-75% of cases reported in surgical series. The hippocampus is involved in the genesis of the seizures and hippocampal sclerosis (HS) is the most frequent neuropathological finding observed in surgical samples. However extra-hippocampal neocortical structures may also be involved and the focal cortical dysplasia (FCD) is the most common second alteration frequently associated with HS. Aim of this project was to clarify, both at radiological and neuropathological level, the abnormalities frequently observed in the temporal pole of many TLE patients as the focal cortical dysplasia, the hippocampal sclerosis and the radiological alteration of grey/white matter boundary called “blurring”. The study was performed on surgical specimens of human temporal cortices and hippocampi from TLE patients and autoptic hippocampi at different stage of development submitted first to high resolution (7T) MRI and then processed for histological analysis. Comparison between 7T MRI data with corresponding histological and immunohistochemical features was done. The first part of this study demonstrates that thanks to differences in MRI signal intensities, depending on different density and distribution of cells and myelin fibres, high-resolution ex-vivo MRI enables to visualize the intracortical organization in normal and pathological areas and can detect the subtle architectural alterations in samples presenting dysplastic cortex. The temporo-polar blurring has demonstrated to be due to a great degeneration of fibre bundles in the white matter and, since the age at epilepsy onset is earlier in patients with blurring in comparison to those without blurring, these data suggest that it consists in a slowly evolving chronic degeneration process with the redistribution of the remaining fibres. The comparative imaging-histology investigation on healthy hippocampal specimens shows that 7T MRI can identify the main anato
- Published
- 2014