Diagnosing dementia in multiple system atrophy by applying Movement Disorder Society diagnostic criteria for Parkinson's disease dementia

Abstract Introduction Dementia is an exclusion criterion in current consensus diagnostic criteria, while growing evidence suggests the occurrence of cognitive dysfunction and even dementia in multiple system atrophy (MSA) patients. The main goal of this study was to determine if Movement Disorder Society (MDS) Parkinson's disease dementia (PDD) LEVEL-1 criteria are useful in screening for dementia in MSA patients compared to full cognitive testing (LEVEL-2 criteria). Methods In this retrospective study, MDS diagnostic criteria for PDD were applied in 111 MSA patients from three centres. LEVEL-1 evaluation (short screening test) was compared to LEVEL-2 examination (extensive neuropsychological gold standard assessment). Sensitivity, specificity, positive and negative predictive values were calculated for LEVEL-1 compared to LEVEL-2. Two Mini Mental State Examination (MMSE) cut-off scores were evaluated (