Abstract #3657

Axial and Radial Diffusion Changes in Recently-Diagnosed Patients with Obstructive Sleep Apnea

Rajesh Kumar¹, Paul M. Macey², Mary A. Woo², Frisca L. Yan-Go³, Ronald M. Harper¹

¹Neurobiology, University of California at Los Angeles, Los Angeles, CA, United States; ²UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA, United States; ³Neurology, University of California at Los Angeles, Los Angeles, CA, United States

Obstructive sleep apnea (OSA) patients show gray matter and axonal injury in areas that control autonomic, cognitive, and mood functions, deficient in OSA; however, the nature of brain injury (axonal or myelin) in newly-diagnosed OSA subjects is unclear. We examined global and regional axial and radial diffusivity in newly-diagnosed OSA, which assess axonal and myelin changes, respectively, and found significantly reduced global diffusion values, reflected as localized changes in various brain areas, including the medullary, cerebellar, basal-ganglia, and limbic sites. Radial diffusion changes in OSA were more widespread than axial, indicating predominant myelin pathology over axons, possibly resulting from hypoxemia.