GFAP and Parkinson disease: In the assessment of potential differences in CSF biomarker levels of cognitively impaired participants (MoCA score <26) and those with a MoCA score >26, we found significantly increased CSF biomarker levels for the markers GFAP (p<0,0001), NfL (p<0,0001), S100 (p<0,05), sTREM2 (p<0,05) and YKL40 (p<0,01) in the PD-MCI group.