Premotor symptoms and the risk of Parkinson's disease: A case-control study in Mexican population

To assess the prevalence of pre-motor symptoms and estimate the risk for developing Parkinson's disease in Mexican population.

A case-control study was carried out with consecutive subjects with Parkinson's disease from two different referral centers in Mexico. Gender- and age-matched controls were randomly selected from the participating hospitals. All subjects were assessed using a structured questionnaire for the assessment of pre-motor symptoms (hyposmia, depression, anxiety, constipation, and sleep disorders). Odds ratios (OR) were calculated using logistic regression analysis.

A total of 430 subjects with PD and 430 healthy subjects were included. Premotor symptoms prevalence was 77.7% (n=334) for the PD group, compared to 41.3% (n=178) in the control group (p<0.001). After logistic multivariate analysis, previous history of hyposmia (OR 2.02 [95% CI 1.33-3.06]), depression (OR 2.52 [95% CI 1.67-3.84]), anxiety (OR 4.37 [95% CI 2.73-6.98]) and sleep disorders (OR 2.03 [95% CI 1.41-2.93]) were independently associated with Parkinson's disease. Overall prediction success of the model was 81.2% for controls and 61.2% for subjects with PD.

All five premotor symptoms assessed were more commonly reported in PD subjects than healthy controls. The presence of non-motor symptoms yield a prediction success of 71.2% to discriminate between PD subjects and healthy controls.