Prevalence of Prodromal Symptoms of Parkinson's Disease in the Late Middle-Aged Population.

BACKGROUND: The prodromal phase of Parkinson's disease (PD) can last up to 20 years and is characterized by a variety of non-motor symptoms. OBJECTIVE: To determine the prevalence of a selection of non-motor symptoms known to be associated with an increased risk of developing PD in a late middle-aged population-based sample and to determine their association with motor function. METHODS: At a mean age of 60.3 years, 775 subjects were recruited from the Longitudinal Aging Study Amsterdam (LASA). Hyposmia, cognitive impairment, patient-reported constipation, possible REM-sleep behavior disorder, depression, and anxiety were indexed as known PD risk factors. Additionally, 1) the PD screening questionnaire, 2) four physical performance tests, and 3) a functional limitations questionnaire, were used to determine whether the presence of two or more PD risk factors was associated with reduced motor function. RESULTS: The prevalence of single risk factors ranged between 3 and 13%. Approximately 11% of subjects had two or more PD risk factors. Motor functioning of subjects with two or more PD risk factors was significantly worse than performance of subjects without or with a single risk factor (all p values≤0.001). CONCLUSION: Approximately 11% of the late middle-aged population has two or more known PD risk factors. Among these subjects self-perceived PD symptoms and reduced physical performance are more prevalent, suggesting that at least some of these subjects may be in the prodromal phase of PD.

Hyposmia as a marker of (non-)motor disease severity in Parkinson's disease.

The aim of this study was to evaluate the relationship of hyposmia in Parkinson's disease (PD) with other motor and non-motor symptoms and with the degree of nigrostriatal dopaminergic cell loss. A total of 295 patients with a diagnosis of PD were included. Olfactory function was measured using the University of Pennsylvania Smell Identification Test (UPSIT). Motor symptoms were rated using the Unified Parkinson's Disease Rating Scale motor subscale (UPDRS III). To evaluate other non-motor symptoms, we used the Mini-Mental State Examination (MMSE) as a measure of global cognitive function and validated questionnaires to assess sleep disturbances, psychiatric symptoms, and autonomic dysfunction. A linear regression model was used to calculate correlation coefficients between UPSIT score and motor and non-motor variables [for psychiatric symptoms a Poisson regression was performed]. In a subgroup of patients (n = 155) with a dopamine transporter (DaT) SPECT scan, a similar statistical analysis was performed, now including striatal DaT binding. In the regression models with correction for age, sex, disease duration, and multiple testing, all motor and non-motor symptoms were associated with UPSIT scores. In the subgroup of patients with a DaT-SPECT scan, there was a strong association between olfactory test scores and DaT binding in both putamen and caudate nucleus. Hyposmia in PD is associated with various motor and non-motor symptoms, like cognition, depression, anxiety, autonomic dysfunction and sleep disturbances, and with the degree of nigrostriatal dopaminergic cell loss. This finding adds further confirmation that hyposmia holds significant promise as a marker of disease progression.

Flavor perception and the risk of malnutrition in patients with Parkinson's disease.

Flavor perception involves both olfactory and gustatory function. In patients with Parkinson's disease (PD), hyposmia is a frequent finding, as well as an increased risk of malnutrition. We performed a pilot study to investigate the relationship between flavor perception and risk of malnutrition in PD patients. 63 PD patients participated to perform an olfactory (Sniffin' Sticks) and gustatory (Taste Strips) task, and a questionnaire to establish nutritional risk (MUST), which includes BMI measurements. The relationship between olfactory and gustatory function and BMI was analyzed using partial correlations, corrected for disease duration, and regression analysis. Patients displayed a high prevalence of hyposmia (68.3%), and a low prevalence (6.3%) of hypogeusia. A small, but significant correlation was found between olfactory function and BMI (r = 0.261, p = 0.038), and not for gustatory function and BMI (r = 0.137, p = 0.284). Hyposmia, and not hypogeusia, may contribute to weight loss in Parkinson's disease, and hence increase the risk of malnutrition.

Motor and non-motor correlates of olfactory dysfunction in Parkinson's disease.

Hyposmia is highly prevalent in the motor phase of Parkinson's disease (PD) and is an established pre-motor sign of PD that may precede the onset of motor symptoms by as long as 5 years. The data presented here are part of an ongoing study to determine the relationship of the olfactory deficit in PD with both motor and non-motor features of the disease. The study population so far includes 96 patients with a clinical diagnosis of PD (UK PD Society Brain Bank criteria; mean age 64.9 years; mean disease duration 4.8 years). Olfactory testing was performed using the 40-item UPSIT. We analyzed the relationship between UPSIT scores and measures of motor (disease duration, stage and severity) and non-motor (cognitive function, depression, anxiety and sleep) function. In 60 PD patients, [(123)I]FP-CIT SPECT scans were available to assess the relationship between UPSIT scores and striatal dopamine transporter (DAT) binding. Preliminary analyses revealed correlations of the olfactory deficit in PD with both motor and non-motor features, as well as with striatal DAT binding. These data suggest that the olfactory deficit in PD is not stationary by the time the motor phase is entered, but continues to progress over time. Hyposmia may therefore be useful as a marker of disease progression, at least in the early disease stages.