Clinical validation of movement disorder society-recommended diagnostic criteria for Parkinson's disease with dementia

The objective of this work was to evaluate the Movement Disorders Society (MDS) Task Forceproposed screening checklist for detecting Parkinson's disease dementia (PD-D) in relation to full neuropsychological testing. An MDS Task Force has proposed diagnostic procedures for PD-D, which have not been fully validated against more extensive neuropsychological testing. PD subjects were recruited from 2 specialty centers. A neuropsychologist evaluated them for dementia as part of routine clinical care. Independent clinical neurologists administered the MDS PD-D screening checklist. Diagnosis of PD-D by the 2 methods was compared. Ninety-one PD subjects had a mean age of 66.3 (SD = 9.7) years and a mean PD duration of 8.8 (SD = 6.1) years. Seven subjects (7.7%) met all 8 screening checklist criteria from the MDS PD-D screening tool and were classified as probable PD-D. Fifteen (16.5%) subjects were classified as PD-D by full neuropsychological assessment. The screening checklist showed 100% specificity, but only 46.7% sensitivity, for diagnosing PD-D compared to the full neuropsychological assessment. PD-D cases missed by the PD-D screening tool were largely due to 2 checklist items that were not endorsed (absence of depression and Mini-Mental State Examination [MMSE] scores <26). There was moderate agreement between these 2 methods for determination of PD-D (kappa = 0.59, P < .001). The MDS-PD-D screening checklist is highly accurate for detecting PD-D if all items are endorsed. However, for cases that do not meet these criteria, full neuropsychological testing is needed to differentiate PD-D from milder cognitive impairment. Revision of the checklist by altering or eliminating the 2 problematic checklist items may improve sensitivity. (C) 2011 Movement Disorder Society