REM sleep behavior disorder and REM sleep without atonia in probable Alzheimer disease

Study Objective: To determine the frequency of rapid eye movement (REM) sleep behavior disorder (RBD) and REM sleep without atonia among patients with Alzheimer disease and control subjects. Design: Overnight polysomnography. Settings: Sleep laboratory. Patients: Fifteen patients with probable Alzheimer disease (mean age SD, 70.2 +/- 5.6) and 15 age-matched healthy control subjects (mean age +/- SD, 67.9 +/- 5.4). Intervention: N/A. Results: Four patients with Alzheimer disease presented REM sleep without atonia. One of these patients had all the polysomnographic features of RBD, including behavioral manifestations during REM sleep. Conclusion: RBD is rare, but REM sleep without atonia is relatively frequent in patients with probable Alzheimer disease, a tauopathy.