Visuospatial dysfunction predicts dementia-first phenoconversion in isolated REM sleep behaviour disorder.

Visuospatial dysfunction, as reflected mainly by the modified posterior subscore of MoCA, is a predictive factor for dementia-first phenoconversion in iRBD, suggesting its potential for being a biomarker for clinical prognostic prediction and potential neuroprotective trials aiming to delay or prevent dementia.