Microstructural white matter alterations and hippocampal volumes are associated with cognitive deficits in craniopharyngioma

Context: Patients with craniopharyngioma (CP) and hypothalamic lesions (HL) have cognitive deficits. Which neural pathways are affected is unknown. Objective: To determine whether there is a relationship between microstructural white matter (WM) alterations detected with diffusion tensor imaging (DTI) and cognition in adults with childhood-onset CP. Design: A cross-sectional study with a median follow-up time of 22 (6-49) years after operation. Setting: The South Medical Region of Sweden (2.5 million inhabitants). Participants: Included were 41 patients (24 women, >= 17 years) surgically treated for childhood-onset CP between 1958-2010 and 32 controls with similar age and gender distributions. HI was found in 23 patients. Main outcome measures: Subjects performed cognitive tests and magnetic resonance imaging, and images were analyzed using DTI of uncinate fasciculus, fornix, cingulum, hippocampus and hypothalamus as well as hippocampal volumetry. Results: Right uncinate fasciculus was significantly altered (P <= 0.01) Microstructural WM alterations in left ventral cingulum were significantly associated with worse performance in visual episodic memory, explaining approximately 50% of the variation. Alterations in dorsal cingulum were associated with worse performance in immediate, delayed recall and recognition, explaining 26-38% of the variation, and with visuospatial ability and executive function, explaining 19-29%. Patients who had smaller hippocampal volume had worse general knowledge (P = 0.028), and microstructural WM alterations in hippocampus were associated with a decline in general knowledge and episodic visual memory. Conclusions: A structure to function relationship is suggested between microstructural WM alterations in cingulum and in hippocampus with cognitive deficits in CP.