Automated evaluation of hippocampal subfields volumes in mesial temporal lobe epilepsy and its relationship to the surgical outcome.

ABSTRACT

The International League Against Epilepsy (ILAE) classification system for hippocampal sclerosis (HS) is based on location and extent of hippocampal neuron loss. Specific subgroups have a better surgical prognosis. Automated hippocampal subfields segmentation and volume measure could be obtained from high field MRI and used to pre-operatively classify the patients in ILAE subgroups to define best candidates for surgery. This prospective study included 86 MTLE patients, candidates to surgical treatment and ten healthy volunteers. Volumetric analysis of the hippocampal sublayers was performed through the Freesurfer software, using 3 Teslas volumetric T1 weighted MRI. We correlated the hippocampal subfields measures with the seizure control after one year from surgery. Volume loss in Cornu Amonis (CA) 1 and 4 were related to better surgical outcome after one year. Atrophy in CA 2 and CA 3 did not improve the prognosis. These results are in agreement with the ILAE classification of hippocampal subfields sclerosis.