Clinical Validity of the Mattis Dementia Rating Scale-2 in Parkinson Disease With MCI and Dementia

The utility of the Mattis Dementia Rating Scale 2 (MDRS-2) in screening for dementia in Parkinson disease (PD) is well documented. However, little is known about its sensitivity to mild cognitive impairment in PD (PD-MCI). This study sought to document the validity of the MDRS-2 for diagnoses of PD-MCI and dementia in PD (PDD). Twenty-two healthy controls (HCs), 22 PD-MCI, and 16 PDD were compared on each MDRS-2 subscales and MDRS-2 total standard scores. Patients with PDD performed significantly worse than the other groups (all Ps < .05) on the MDRS-2 total and on all subscales, except attention. PD-MCI had significant lower scores than HCs on the MDRS-2 total and on initiation/perseveration and memory subscales. The optimal cutoff score for PD-MCI diagnosis was <= 140/144 and <= 132/144 for PDD. These findings suggest that MDRS-2 is a useful tool to identify dementia but that there might be a ceiling effect in the MDRS-2 cutoff score to diagnose MCI in PD.