Neuromotor abnormalities and risk for psychosis in Alzheimer's disease.
BACKGROUND
Cross-sectional studies in Alzheimer's disease (AD) show a strong relationship between extrapyramidal motor signs and presence of psychosis, yet it remains unclear whether neuromotor abnormalities precede and therefore can predict development of psychosis in AD.


OBJECTIVE
To identify cognitive and motor risk factors for the development of psychosis in patients with AD.


METHODS
Baseline clinical motor ratings and instrumental measures of neuromuscular function were obtained from 54 nonpsychotic patients with AD who were evaluated annually for 2 years for the development of psychosis. Survival analyses were performed to identify incidence and risks associated with psychosis.


RESULTS
The incidence of new onset psychosis in our sample was 32.5% in 2 years. Patients with abnormal agonist muscle burst amplitudes during rapid alternating movements of the hand were more likely to develop psychosis than those without (OR = 4.31; p = 0.007). Women with AD also had a higher risk of developing psychosis within 2 years than men (OR = 1.33; p = 0.01).


CONCLUSIONS
Using simple noninvasive instrumental procedures for assessing neuromotor function, it may be possible to identify an individual's level of risk for developing psychosis during the course of AD.
Caligiuri
M P
MP
Department of Psychiatry, University of California, San Diego, and the UCSD Alzheimer's Disease Research Center, La Jolla, CA 92093, USA. mcaligiuri@ucsd.edu
Peavy
G
G
Salmon
D P
DP
Galasko
D R
DR
Thal
L J
LJ
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000453:epidemiology*; D015897:Comorbidity; D004576:Electromyography; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D009069:Movement Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000503:physiopathology; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology*; D012016:Reference Values; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D016019:Survival Analysis