Associations of Diffusion Tensor Imaging (DTI), Diffusion Kurtosis Imaging (DKI), and Standard Model Imaging (SMI) metrics with obstructive sleep apnea severity in cognitively unimpaired subjects
Luisa Figueredo1, Jenny Chen2, Naomi Gaggi2, Tovia Jacobs2, Xiaotong Song2, Gabriela Silva-Albornoz2, Moses Gonzalez2, Joshua Gills2, Jaime Ramos-Cejudo2, Indu Ayappa3, Korey Kam3, Anna Mullins3, Ankit Parekh3, Andrew Varga3, Omonigho Bubu2, Esther Blessing2, Els Fieremans2, Ricardo Osorio2
1Psychiatry, NYU Grossman School of Medicine, 2NYU Grossman School of Medicine, 3Mount Sinai
Objective:
Our study aims to comprehensively evaluate the effects of obstructive sleep apnea (OSA) on white matter tracts using diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), and standard model imaging (SMI) diffusion metrics in a cognitively normal older adult population.
Background:
Obstructive sleep apnea (OSA) is a complex condition characterized by repeated episodes of upper airway collapse during sleep, leading to sleep fragmentation and cognitive impairment. Diffusion magnetic resonance imaging (dMRI) techniques, including DTI, DKI, and SMI, offer complementary insights into white matter microstructure
Design/Methods:
150 individuals from a community-based study on sleep, memory, and healthy aging underwent one-night nocturnal polysomnography (NPSG), cognitive assessments, and MRI. OSA measurements included the Apnea-Hypopnea Index (AHI) and sleep characteristics derived from the NPSG. The microstructural properties of white matter tracts (DTI, DKI, and SMI metrics) were estimated after preprocessing dMRI using the DESIGNER pipeline.
Results:
Adjusted models showed negative associations between AHI severity (AHI3A) and Fractional Anisotropy (FA), Axial Diffusivity (AD), and Radial Kurtosis (RK) in the genu of the corpus callosum (GCC) and cingulum, while showing positive associations with Radial Diffusivity (RD). A subject-matched comparison between participants with and without OSA indicated that the OSA group had smaller FA and AD values. ANOVA comparisons of OSA severity revealed that subjects with severe OSA had significantly decreased FA compared to participants with mild or no OSA. The same comparison also showed increased RD values in the GCC and cingulum.
Conclusions:
Our study demonstrates that in individuals with OSA, increasing AHI severity is associated with poorer measures of white matter integrity and organization, as evidenced by reduced FA and AD, and increased RD. Additionally, the regions associated with most of these differences have been linked to memory and executive functions, which have also been previously evaluated as being affected by OSA severity.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.