Quantitative evaluation of hippocampal gray-white matter boundary blurring in medial temporal lobe epilepsy with hippocampal sclerosis

Introduction: The magnetic resonance imaging (MRI) findings of hippocampal sclerosis (HS) include decreased volume, increased signal intensity, and hippocampal gray-white matter boundary blurring (HGWBB). Given that the layered structure is obscure in HS, there have been no reports on the quantita-tive evaluation of HGWBB and its relationship with the clinical outcome. Thus, this study aims to corre-late the extent of HGWBB to its clinical manifestation of HS.Methods: Fifty-four patients with temporal lobe epilepsy who underwent hippocampal resection were enrolled. To evaluate HGWBB quantitatively, we defined an index by calculating the standard deviation of the intrahippocampal signal on short tau inversion recovery. In addition, we created a prognostic scor-ing system using four criteria, including hippocampal signal intensity, size of hippocampal cross-sectional area, presence of temporal lobe lesions, and the HGWBB index.Results: The HGWBB index was significantly lower on the affected side than on the unaffected side (p < 0.001). This trend was more prominent in the poor prognosis group than that in the good prognosis group. The prognostic scoring system revealed that when three or more criteria were positive, the prog-nostic accuracy reached 87.5% sensitivity and 71.7% specificity.Conclusion: The HGWBB index is useful for the diagnosis of temporal lobe epilepsy with HS and for pre-dicting seizure outcomes when used with another index of hippocampal volume loss and increased signal intensity.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study aimed to investigate the relationship between hippocampal sclerosis (HS) and hippocampal gray-white matter boundary blurring (HGWBB) and its impact on clinical outcomes. A total of 54 patients with temporal lobe epilepsy who underwent hippocampal resection were included. The HGWBB index was significantly lower on the affected side compared to the unaffected side, and this trend was more pronounced in the poor prognosis group. A prognostic scoring system combining multiple criteria showed high sensitivity (87.5%) and specificity (71.7%) in predicting seizure outcomes.