Automated Manual Lymphatic Drainage Therapy to Improve Glymphatic Function in OSA Patients

Inclusion Criteria: * Age 50 years and older * Diagnosed with obstructive sleep apnea * On stable, effective, and compliant CPAP therapy for a minimum of 6 months * Willing and able to provide informed consent * Willing and able to use automated manual lymphatic drainage device (Neuroglide) nightly for 1-month and participate in at-home sleep monitoring * Stable on a medication regimen for comorbid medical or mental health disorders for at least 3 months and not planning to undergo therapy adjustment during trial Exclusion Criteria: * Chronic kidney disease (glomerular filtration rate (GFR) \< 60 mL/min/1.73 m² for 3 months or more), due to its potential impact on serum biomarker clearance * Other primary sleep disorders aside from OSA (i.e., narcolepsy, REM Sleep behavior disorder, chronic insomnia, restless legs syndrome), circadian rhythm disorder or shift work * Chronic neurological disorders (e.g. Multiple sclerosis, epilepsy, neurodegenerative disorders, ALS), due to their impact on biomarkers. History of headache (\<15 days a month) and stroke (over 6 months prior to enrollment) are allowed * Physical limitations preventing the use of Neuroglide device (e.g. inability to lay on the back due to pain, inability to setup the device due to limb dysfunction/weakness) * Physical limitations preventing the use or function of Somfit, including forehead skin lesions, history of adhesive allergies, implanted electronic devices (e.g. pacemakers) or the use of CPAP masks with forehead support/bar/pad (Fisher \& Paykel Vitera, Fisher \& Paykel Eson, ResMed Mirage Quattro, ResMed Ultra Mirage Full Face Mask, Philips Respironics ComfortGel Blue), because the forehead piece of the mask would prevent the appropriate application of Somfit for at-home sleep monitoring. Because Somfit algorithms are based on physiological signals that include heart rate and it has not been validated in patients with persistent arrhythmia, we will exclude patients with history of atrial fibrillation and high PVC burden to avoid inaccurate estimates. * Acute cardiopulmonary disorders, infections, injury at/near the application site, abnormal lymphatic system due to previous surgery involving lymphatics or chronic lymphedema, acute inflammatory process (e.g. recent knee/hip surgery, upper respiratory tract infection, cancer not in remission) * Kokmen short test of mental status \< 34 (concern for mild cognitive impairment) * Inability to comply with study procedures