Dementia associated with Parkinson's disease: Applying the Movement Disorder Society Task Force criteria

Background: Diagnostic criteria and procedures for dementia in Parkinson's disease (PDD) have been proposed by a Movement Disorders Society Task Force (MDS-TF). The objective of this study was to explore the utility of the new MDS-TF criteria and procedures in clinical practice. Methods: Two hundred ninety nine PD patients (36.5% with PDD as per MDFS-TF criteria; 33.1% according the DSM-IV) were included in the study. A variety of standardized motor, cognitive, psychiatric, and global severity measures were administered. A multivariate logistic regression model was built to determine the variables producing discrepancy between the MDS-TF and DSM-IV criteria for PDD and the clinical features that distinguished false negative cases. Results: Agreement between MDS-TF and DSM-IV criteria was substantial (87.3%; kappa = 0.72), but the DSM-IV criteria failed to identify 22% of patients fulfilling MDS-TF criteria. False negative cases were older and had more severe motor symptoms but less psychosis than those true non-demented PD. False positives had less severe motor symptoms than true PDD, although the difference did not reach statistical significance. Conclusions: Our findings suggest that the MDS-TF criteria are more sensitive than the DSM-IV for a diagnosis of PDD. Old age, absence of psychiatric symptoms, and severe motor impairment can hinder the diagnosis of PDD.