Cortical thinning and volumetric alterations in patients with unruptured intracranial aneurysms: insights from surface-based morphometry.

Unruptured intracranial aneurysms (UIAs) are increasingly detected incidental findings, traditionally considered asymptomatic. However, emerging evidence links their presence to subtle cognitive and neuropsychiatric alterations. The underlying neuroanatomical correlates of these effects remain poorly understood. To investigate cortical morphological alterations in patients with UIA using surface-based morphometry and to assess their associations with aneurysm size and location. We prospectively enrolled 223 participants between May 2023 and May 2025, including 73 patients with UIA and 73 PSM-matched healthy patients. All patients underwent head MRI. Cortical reconstruction and parcellation were performed using FreeSurfer to extract measures of cortical thickness, volume, and curvature. General linear models with cluster-wise correction were used for between-group and correlation analyses. Compared with matched controls, UIA patients exhibited significant cortical thinning and volume reduction in bilateral temporal regions, including the superior and inferior temporal gyri, parahippocampal gyrus, and pars opercularis (p < 0.01). Patients with internal carotid artery aneurysms demonstrated higher cortical volume in parietal and frontal regions relative to those with middle cerebral artery aneurysms (p < 0.01). Aneurysm dome size correlated negatively with cortical volume in bilateral superior temporal gyri (p < 0.01). No differences were found between left- and right-sided aneurysms. UIA presence is associated with regionally reduced cortical thickness and volume, predominantly within limbic-temporal and frontotemporal networks. These alterations correlate with aneurysm size and location, suggesting a link between aneurysm-related vascular or inflammatory processes and cortical structural reorganization.