Effect of Treating Sleep Apnea on Cognition in Patients With Dementia

Patients with sleep disordered breathing (SDB) experience nighttime sleep fragmentation and often become hypoxic during the night. The fragmentation and hypoxemia can frequently result in daytime impairments including impairments in cognitive functioning. The state-of-the-art treatment for SDB is Continuous Positive Airway Pressure (CPAP). Many SDB patients who are successfully treated with CPAP show improvement in memory and other cognitive functions. Data have shown that there is a strong relationship between SDB and dementia with patients with Alzheimer's Disease (AD) having a high rate of SDB. This proposal will examine whether treating SDB with CPAP in patients with AD will result in improvement in cognitive functioning. The specific aims are to assess whether patients with mild AD and SDB will tolerate CPAP and be compliant with treatment; to examine the effect of CPAP treatment on SDB in patients with mild AD and SDB; to examine the effect of CPAP treatment on cognitive functioning in patients with mild AD and SDB; to examine whether improvement is greater after six weeks of CPAP treatment than after three weeks of treatment. Since caregivers are often disturbed by the patients poor sleep, we will also evaluate the effect of the patients' treatment on their caregivers. Specifically, the secondary aims are to evaluate whether caregivers feel that CPAP improves the patient's sleep and to evaluate whether caregivers feel that their own sleep improves as the patient's sleep improves. Patient identified as having mild AD and SDB will have an extensive neuropsychological battery. Half will be randomized to CPAP treatment and the other half to shamCPAP. After three weeks neuropsychological tests will be repeated. The shamCPAP will be switched to CPAP and the CPAP group will remain on CPAP for an additional three weeks. Neuropsychological tests will again be repeated. The long-term goal of this line of research is to find a new approach that might improve the quality of life, delay the dementing process, postpone institutionalization and save millions of dollars in nursing care costs.