title: Hallucinations and sleep-wake cycle in Alzheimer's disease: a questionnaire-based study in 218 patients.
abstract: The aim was to evaluate the relationship between hallucinations and the sleep-wake cycle in a sample of Alzheimer's disease (AD) patients in the early-moderate stage. Two hundred and eighteen AD patients (66 males, 152 females, mean age 74.3+/-6.85) were administered a sleep questionnaire in the presence of a care-giver. Twenty-six out of 218 (12%) reported the occurrence of hallucinations, mainly visual. In 18/28 (69%) hallucinations occurred when the patient was awake and in 8 (31%) hallucinations were reported to occur close to a specific phase of the sleep-wake cycle. Vivid dreams were reported in 25/218 (11%) and violent sleep-related and dream-related behaviours (probable REM behaviour episodes) in 22/218 (10%). Both REM phenomena were more frequent in AD hallucinators than in AD non-hallucinators (26.9% vs. 9.3%, and 26.9% vs. 7.8%, p<0.007). Our data indicate a lower incidence of hallucinations and presumable REM behaviour disorder (RBD) in AD, at least in the early-moderate phase, than that observed in synucleinopathies. However, the higher occurrence of vivid dreams and RBD in AD patients with hallucinations compared to those without hallucinations indicates a potential role of disordered REM sleep in influencing the occurrence of hallucinations in AD, similar to what has been observed in synucleinopathies.
authors.affiliation: UVA/Lab. of Neuropsychology, IRCCS C. Mondino, Via Mondino 2, I-27100 Pavia, Italy. elena.sinforiani@mondino.it
authors.forename: E
authors.initials: E
authors.lastname: Sinforiani
authors.forename: M
authors.initials: M
authors.lastname: Terzaghi
authors.forename: C
authors.initials: C
authors.lastname: Pasotti
authors.forename: C
authors.initials: C
authors.lastname: Zucchella
authors.forename: E
authors.initials: E
authors.lastname: Zambrelli
authors.forename: R
authors.initials: R
authors.lastname: Manni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology; D018450:Disease Progression; D005260:Female; D006212:Hallucinations / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D012890:Sleep / Q000502:physiology; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D012895:Sleep, REM / Q000502:physiology; D011795:Surveys and Questionnaires; D014851:Wakefulness / Q000502:physiology