Natural sleep at home and psychosis in patients with Parkinson's disease: A post-hoc analysis of the ZEAL study.

OBJECTIVES

Psychosis remains problematic in patients with Parkinson's disease and sleep disorders are frequent non-motor symptoms of PD. Few research studies have correctly assessed objective sleep architecture to determine the association between psychosis and sleep disorders. A mobile two-channel electroencephalography (EEG)/electrooculography (EOG) recording system is a self-applicable and affordable method for objectively measuring sleep at home. We studied patients with PD who were enrolled in ZEAL study of the randomized placebo-control clinical trial investigating the efficacy of zonisamide for sleep disorders to determine whether sleep disorders and psychosis are related by using the EEG/EOG recording system.

METHODS

24 independent variables were evaluated and variables with a statistically significant correlation (p < 0.05) to psychosis on univariate logistic regression analyses were entered into multivariate logistic regression analysis using forced entry.

RESULTS

Forty-one patients with PD with no missing data, in both the potable EEG/EOG recording device and subjective clinical characteristics before the initiation of zonisamide, were analyzed. The major result was the reduced total sleep time (TST) and time spent in REM sleep, identified by univariate logistic regression analysis, in PD patients with psychosis. Multivariate logistic regression analysis identified nocturnal PD symptoms on the PDSS as a significant risk factor for psychosis (OR 1.409, 95 %CI 1.073-1.850; p = 0.014).

CONCLUSION

Our findings reveal that the nocturnal PD symptoms that affect regular home-based sleep may be associated with psychosis.