Visuospatial dysfunction indicates an increased risk of rapid dementia conversion in Parkinson's disease

INTRODUCTION: The aim of this study was to define cognitive subtypes of early-stage Parkinson's disease (PD) based on temporal evolutionary patterns of domain-specific decline. METHODS: We retrospectively enrolled 474 patients with early-stage PD who underwent detailed neuropsychological testing at initial assessment. Age- and education-specific z-scores from 13 neuropsychological subtests were used to apply Subtype and Stage Inference (SuStaIn) to identify distinct cognitive subtypes. We compared the risk of developing dementia between subtypes. RESULTS: SuStaIn analysis delineated three pd subtypes with cognitive impairment: Subtype 1 (n = 121) with early verbal memory impairment; Subtype 2 (n = 108) with early visuospatial dysfunction; and Subtype 3 (n = 87) with early frontal/executive dysfunction. The remaining 158 patients were classified as a cognitively intact subtype (Subtype 0). Time-dependent Cox regression models showed that the risk of dementia after 3.5 years was highest in Subtype 2. DISCUSSION: Visuospatial dysfunction may be a potential cognitive profile for predicting the risk of rapid dementia conversion in PD. HIGHLIGHTS: Cognitive profile associated with early dementia conversion in Parkinson's disease (PD) remains unclear. This study applied the SuStaIn algorithm to delineate three cognitive subtypes of PD. PD subtype with early visuospatial dysfunction had a higher risk of dementia. Visuospatial dysfunction indicates an imminent risk of dementia conversion in PD.