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Published on: November 21, 2013
Minor Phenomena in Parkinson's Disease-Prevalence, Associations, and Risk of Developing Psychosis
Ruth B Schneider1,2, Peggy Auinger1,2, Roseanne D Dobkin3
1Department of Neurology, University of Rochester, Rochester, NY, USA.
Background:
Minor phenomena, including passage phenomena, feeling of presence, and illusions, are common and may represent a prodromal form of psychosis in Parkinson's disease (PD). We examined the prevalence and clinical correlates of minor phenomena, and their potential role as a risk factor for PD psychosis.
Methods:
A novel questionnaire, the Psychosis and Mild Perceptual Disturbances Questionnaire for PD (PMPDQ), was completed by Fox Insight cohort participants with and without PD. Additional assessments included the Non-Motor Symptoms Questionnaire (NMSQuest), REM Sleep Behavior Disorder Single Question Screen (RBD1Q), Movement Disorder Society-Unified Parkinson Disease Rating Scale Part II, demographic features, and medication usage. For participants with PD, we used regression models to identify clinical associations and predictors of incident psychosis over one year of follow-up.
Results:
Among participants with PD (n = 5950) and without PD (n = 1879), the prevalence of minor phenomena was 43.1% and 31.7% (P < .001). Of the 3760 participants with PD and no baseline psychosis, independent correlates of minor phenomena included positive responses on the NMSQuest apathy/attention/memory (OR 1.7, 95% CI 1.3-2.1, P < .001) or sexual function domain (OR 1.3, 95% CI 1.1-1.6, P = .01) and positive RBD1Q (OR 1.3, 95% CI 1.05-1.5, P = .01). Independent risk factors for incident PD psychosis included the presence of minor phenomena (HR 3.0, 95% CI 2.4-3.9, P < .001), positive response on the NMSQuest apathy/attention/memory domain (HR 1.8, 95% CI 1.3-2.6, P < .001), and positive RBD1Q (HR 1.5, 95% CI 1.1-1.9, P = .004).
Conclusions:
Minor phenomena are common, associated with specific non-motor symptoms, and an independent predictor of incident psychosis in PD.
Insights
Minor phenomena are common in Parkinson's disease (PD) and predict psychosis. Identifying these symptoms early can help manage PD psychosis risk.
Area of Science:
- Neurology
- Psychiatry
- Neuroscience
Background:
- Minor phenomena, such as passage phenomena, feeling of presence, and illusions, are frequently observed in Parkinson's disease (PD).
- These experiences may indicate an early stage of psychosis in individuals with PD.
- Understanding their prevalence and clinical associations is crucial for predicting PD psychosis.
Purpose of the Study:
- To determine the prevalence of minor phenomena in individuals with and without PD.
- To identify clinical factors associated with minor phenomena in PD.
- To assess the role of minor phenomena as a risk factor for developing psychosis in PD.
Main Methods:
- Utilized the novel Psychosis and Mild Perceptual Disturbances Questionnaire for PD (PMPDQ) in the Fox Insight cohort.
- Administered additional assessments including NMSQuest, RBD1Q, MDS-UPDRS Part II, and demographic/medication data.
- Employed regression models to analyze associations and predict incident psychosis over one year in PD participants.
Main Results:
- Minor phenomena were more prevalent in PD (43.1%) than in controls (31.7%).
- In PD patients without baseline psychosis, minor phenomena correlated with apathy/attention/memory and sexual function domains on NMSQuest, and RBD1Q.
- Minor phenomena, NMSQuest apathy/attention/memory, and RBD1Q independently predicted incident PD psychosis.
Conclusions:
- Minor phenomena are a common occurrence in Parkinson's disease.
- These phenomena are linked to specific non-motor symptoms and REM sleep behavior disorder.
- The presence of minor phenomena is a significant independent predictor of future psychosis in PD patients.
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