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 with-out 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 fre-quent in patients with probable Alzheimer disease, a tauopathy.