Delirium in Parkinson's disease patients. A five-year follow-up study

Objective: To assess the significance of delirium in parkinsonian patients in a 5-year follow-up case-control study with three groups of patients: Parkinsonian and Delirium (PDG), Parkinsonian (PG) and Control (CG). Methods: Comparisons of Short Test of Mental Status (STMS) and Unified Parkinson's Disease Rating Scale-motor section (UPDRS(m)) between groups were performed using analysis of variance with repeated measurements. Comparisons of survival functions and Cox regression models were used to analyse the time until death. Results: STMS and UPDRS(m) mean scores were statistically different between PDG group and the other two groups (p<0.001) and between PDG and PG groups (p<0.001), respectively. Including all groups, PG's patients (HR=0.29; 95% C.I.=0.09-0.93) and CG's patients (HR=0.13; 95% C.I.=0.03-0.60) had less hazard to die than PDG's patients; patients with a STMS basal score >33 (HR=0.37; 95% C.I.=0.13-0.99) had less hazard to die than patients with a score ≤33. Finally, including PDG and PG groups, patients with basal UPDRS(m) score >17 (HR=4.88; 95% C.I.=1.11-21.48) had higher hazard to die than patients with a score ≤17. Conclusion: For patients with Parkinson's, delirium is an increased risk factor for developing dementia, to have a more severe motor impairment and to death.