Rapid eye movement sleep behavior disorder (RBD) is linked to other α-synucleinopathies such as Parkinson's disease and Lewy body dementia. It is essential to consider and exclude RBD while studying CSF markers in the latter two to avoid confounding bias and improve test results' specificity.
Keywords: Cerebrospinal fluid; Lewy body dementia; Parkinson disease; REM sleep behavior disorder.