Objective:To explore the morphological characteristics of the corpus callosum (CC) in patients with unilateral medial temporal lobe epilepsy (mTLE) with hippocampal sclerosis (HS), and their correlation with hippocampal volume and clinical indicators.Methods:This was a cross-sectional study. Clinical (age of onset, disease duration, seizure frequency, seizure duration, etc.) and imaging data of 44 patients mTLE with unilateral HS confirmed by postoperative pathology and 42 healthy controls (HCs) recruited at West China Hospital of Sichuan University from June 2017 to May 2023 were analyzed retrospectively. Among the 44 patients, 19 had left-sided HS and 25 had right-sided HS. All subjects underwent high-resolution 3D T 1WI. Hippocampal volumes were obtained using FreeSurfer. ART was used to measure the morphological parameters of the CC for each participant, including total CC area, volume, perimeter, length, thickness, circularity, and the area of seven CC subregions defined by Witelson: rostrum, genu, body, anterior midbody, posterior midbody, isthmus and splenium. Differences in these metrics between two or three groups were compared using independent samples t-test or one-way ANOVA. Pearson or Spearman correlation analysis was used to observe the correlation between morphological features of the CC and hippocampal volume and other clinical indicators in patients with mTLE with unilateral HS. Results:Compared with HCs, patients with mTLE with unilateral HS had significantly reduced total CC area, CC circularity, as well as the area and thickness of the genu, anterior midbody, posterior midbody, isthmus, splenium, and the area of the rostrum ( P<0.05). Significant differences were observed in the total area, circularity, and subregional areas (genu, rostrum, anterior midbody, posterior midbody, splenium), as well as thickness (genu, anterior midbody, posterior midbody, isthmus) of the CC among mTLE with left-sided HS, mTLE with right-sided HS, and HCs ( P<0.05). When compared to HCs, the total area of the CC, circularity and the areas of the genu, rostrum, anterior midbody, posterior midbody, and splenium, and the thicknesses of the genu, anterior midbody, posterior midbody, and isthmus of the CC were significantly reduced in patients with mTLE with right-sided HS ( P<0.05), and the thicknesses of the midbody and isthmus of the CC were significantly reduced in patients with mTLE with left-sided HS compared to HCs ( P<0.05), and the two-by-two comparison of the rest of the indicators did not show statistically significant differences ( P>0.05). Correlation analysis showed that some morphological abnormalities in the CC in mTLE with unilateral HS patients were significantly correlated with age of onset, disease duration, seizure frequency, seizure duration, and hippocampal volume. Conclusions:mTLE with unilateral HS patients can exhibit morphological abnormalities in the CC, particularly in those with right-sided lesions. These abnormalities are significantly associated with seizure-related factors and hippocampal atrophy.

Objective:To explore the morphological characteristics of the corpus callosum (CC) in patients with unilateral medial temporal lobe epilepsy (mTLE) with hippocampal sclerosis (HS), and their correlation with hippocampal volume and clinical indicators.Methods:This was a cross-sectional study. Clinical (age of onset, disease duration, seizure frequency, seizure duration, etc.) and imaging data of 44 patients mTLE with unilateral HS confirmed by postoperative pathology and 42 healthy controls (HCs) recruited at West China Hospital of Sichuan University from June 2017 to May 2023 were analyzed retrospectively. Among the 44 patients, 19 had left-sided HS and 25 had right-sided HS. All subjects underwent high-resolution 3D T 1WI. Hippocampal volumes were obtained using FreeSurfer. ART was used to measure the morphological parameters of the CC for each participant, including total CC area, volume, perimeter, length, thickness, circularity, and the area of seven CC subregions defined by Witelson: rostrum, genu, body, anterior midbody, posterior midbody, isthmus and splenium. Differences in these metrics between two or three groups were compared using independent samples t-test or one-way ANOVA. Pearson or Spearman correlation analysis was used to observe the correlation between morphological features of the CC and hippocampal volume and other clinical indicators in patients with mTLE with unilateral HS. Results:Compared with HCs, patients with mTLE with unilateral HS had significantly reduced total CC area, CC circularity, as well as the area and thickness of the genu, anterior midbody, posterior midbody, isthmus, splenium, and the area of the rostrum ( P<0.05). Significant differences were observed in the total area, circularity, and subregional areas (genu, rostrum, anterior midbody, posterior midbody, splenium), as well as thickness (genu, anterior midbody, posterior midbody, isthmus) of the CC among mTLE with left-sided HS, mTLE with right-sided HS, and HCs ( P<0.05). When compared to HCs, the total area of the CC, circularity and the areas of the genu, rostrum, anterior midbody, posterior midbody, and splenium, and the thicknesses of the genu, anterior midbody, posterior midbody, and isthmus of the CC were significantly reduced in patients with mTLE with right-sided HS ( P<0.05), and the thicknesses of the midbody and isthmus of the CC were significantly reduced in patients with mTLE with left-sided HS compared to HCs ( P<0.05), and the two-by-two comparison of the rest of the indicators did not show statistically significant differences ( P>0.05). Correlation analysis showed that some morphological abnormalities in the CC in mTLE with unilateral HS patients were significantly correlated with age of onset, disease duration, seizure frequency, seizure duration, and hippocampal volume. Conclusions:mTLE with unilateral HS patients can exhibit morphological abnormalities in the CC, particularly in those with right-sided lesions. These abnormalities are significantly associated with seizure-related factors and hippocampal atrophy.