Nur Dikmeer1, Lutfullah Besiroglu1, Maria A Di Biase2,3, Andrew Zalesky3,4, Meltem I Kasal1, Aslıhan Bilge1, Ercan Durmaz1, Serap Polat1, Fazil Gelal5, Nabi Zorlu1. 1. Department of Psychiatry, Katip Celebi University, Ataturk Education and Research Hospital, Izmir, Turkey. 2. Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. 3. Department of Psychiatry, Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia. 4. Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC, Australia. 5. Department of Radiodiagnostics, Katip Celebi University, Ataturk Education and Research Hospital, Ankara, Turkey.
Abstract
OBJECTIVE: We aimed to examine white matter microstructure and connectivity in individuals with obsessive-compulsive disorder (OCD) and their unaffected siblings, relative to healthy controls. METHODS: Diffusion-weighted magnetic resonance imaging (dMRI) scans were acquired in 30 patients with OCD, 21 unaffected siblings, and 31 controls. We examined white matter microstructure using measures of fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). Structural networks were examined using network-based statistic (NBS). RESULTS: Compared to controls, OCD patients showed significantly reduced FA and increased RD in clusters traversing the left forceps minor, inferior fronto-occipital fasciculus, anterior thalamic radiation, and cingulum. Furthermore, the OCD group displayed significantly weaker connectivity (quantified by the streamline count) compared to controls in the right hemisphere, most notably in edges connecting subcortical structures to temporo-occipital cortical regions. The sibling group showed intermediate streamline counts, FA and RD values between OCD and healthy control groups in connections found to be abnormal in patients with OCD. However, these reductions did not significantly differ compared to controls. CONCLUSION: Therefore, siblings of OCD patients display intermediate levels in dMRI measures of microstructure and connectivity, suggesting white matter abnormalities might be related to the familial predisposition for OCD.
OBJECTIVE: We aimed to examine white matter microstructure and connectivity in individuals with obsessive-compulsive disorder (OCD) and their unaffected siblings, relative to healthy controls. METHODS: Diffusion-weighted magnetic resonance imaging (dMRI) scans were acquired in 30 patients with OCD, 21 unaffected siblings, and 31 controls. We examined white matter microstructure using measures of fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). Structural networks were examined using network-based statistic (NBS). RESULTS: Compared to controls, OCDpatients showed significantly reduced FA and increased RD in clusters traversing the left forceps minor, inferior fronto-occipital fasciculus, anterior thalamic radiation, and cingulum. Furthermore, the OCD group displayed significantly weaker connectivity (quantified by the streamline count) compared to controls in the right hemisphere, most notably in edges connecting subcortical structures to temporo-occipital cortical regions. The sibling group showed intermediate streamline counts, FA and RD values between OCD and healthy control groups in connections found to be abnormal in patients with OCD. However, these reductions did not significantly differ compared to controls. CONCLUSION: Therefore, siblings of OCDpatients display intermediate levels in dMRI measures of microstructure and connectivity, suggesting white matter abnormalities might be related to the familial predisposition for OCD.
Authors: Samantha Baldi; Stijn Michielse; Chris Vriend; Martijn P van den Heuvel; Odile A van den Heuvel; Koen R J Schruers; Liesbet Goossens Journal: Hum Brain Mapp Date: 2022-06-23 Impact factor: 5.399