Brain volumetric analysis in pediatric non-lesional occipital lobe epilepsy

Aims: Occipital lobe epilepsy (OLE) is a rare focal epilepsy syndrome, and structural brain alterations in children with non-lesional OLE remain poorly understood. This study aimed to evaluate global and regional brain volumetric characteristics using automated magnetic resonance imaging (MRI) volumetric analysis in children with non-lesional OLE. Methods: This retrospective case-control study included 12 children diagnosed with non-lesional OLE and 10 age- and gender-matched controls who underwent brain MRI for headache evaluation and had no structural abnormalities on conventional MRI. High-resolution three-dimensional T1-weighted brain MRI acquired using a 1.5-T scanner was analyzed with the automated vol2Brain platform. Global volumetric measurements included intracranial volume, total brain volume, gray matter volume, white matter volume, hippocampal volume, amygdala volume, and thalamic volume. Regional analyses included total occipital lobe volume, occipital cortical thickness, calcarine cortex, cuneus, lingual gyrus, inferior, middle, and superior occipital gyri, and occipital pole. Volumetric measurements were compared between the two groups. Results: No statistically significant differences were observed between children with OLE and controls regarding global brain volumes, subcortical structures, total occipital lobe volume, occipital cortical thickness, or regional occipital volumetric measurements (all uncorrected p>0.05). None of the volumetric comparisons was statistically significant after Benjamini-Hochberg false discovery rate (FDR) or Bonferroni correction. Conclusion: Children with non-lesional OLE did not demonstrate statistically significant global or regional brain volumetric differences compared with controls. The present findings therefore do not establish a specific volumetric pattern in pediatric non-lesional OLE and should be considered exploratory given the small sample size. Larger multicenter studies are needed to determine whether reproducible structural abnormalities can be identified in pediatric non-lesional OLE.