Evaluating Obstructive Sleep Apnea Neuropathophysiology with 1H-MRS and Cerebral Small Vessel Disease Imaging

Motivation: 1H-MRS may be sensitive enough to detect neuropathological mechanisms of cerebral small vessel disease in obstructive sleep apnoea (OSA). Goal(s): To investigate the relationships between nocturnal blood pressure surges (caused by sleep disturbances) and hypoxic burden (due to recurring apnoeas) on 1H-MRS metabolite levels and cognitive performance. Approach: Seven controls and 23 participants with OSA underwent brain MRI, sleep physiological assessment and neuropsychological battery. Results: A higher hypoxic burden was associated with higher cellular energy (Cr/H2O) and acute inflammation (GPC/H20), while more frequent blood pressure surges were associated with higher chronic neuroinflammation (mI/H20). There were no associations with cognitive performance. Impact: Estimates of 1H-MRS metabolite levels, along with CSVD standard neuroimaging assessment, provide additional information concerning the neuro-cardiovascular and hypoxic burden associated with OSA that could potentially translate into improved early CSVD diagnosis in high-risk populations due to OSA.