Mixed Dementia

This is a longitudinal observational study recruiting individuals between the ages of 50 and 90 with different types of dementia as well as a comparison group without cognitive deficits. Participants are/will be recruited at sites across Canada and will undergo assessments, neuroimaging, and biological sample collection.

Obstructive sleep apnea (OSA), which causes abnormal pauses in breathing during sleep, is common in patients with vascular cognitive impairment (VCI) and Alzheimer's disease (AD), and exacerbates the cognitive deficits seen in these conditions. OSA is typically treated with continuous positive airway pressure (CPAP), which has been shown to improve cognition in VCI and slow cognitive decline in AD. Despite the need to identify OSA in patients with VCI/AD, these patients often do not undergo testing for OSA. One major barrier is that in-laboratory polysomnography (iPSG), the current standard for diagnosing OSA, is inconvenient for patients with VCI/AD who may be reliant on others for care or require familiar sleep environments. A convenient and cheaper alternative to iPSG is home sleep apnea testing (HSAT), which has been validated against iPSG to diagnose OSA and has proven feasible for use in VCI/AD. Our primary objective is to determine whether the use of HSAT is superior to iPSG in terms of the proportion of patients who complete sleep testing by 6 months post-randomization. We will also investigate cost-effectiveness, patient satisfaction, proportion of patients treated with CPAP, changes in cognition, mood, sleep-related and functional outcomes between HSAT and iPSG at 6 months.