“…The increased risk for developing cognitive impairment and dementia of PD patients in comparison with the general population makes it reasonable to link AD markers such as Aβ42 to PDD. Several studies have shown similar (Holmberg et al, 2003; Mollenhauer et al, 2006; Ohrfelt et al, 2009; Přikrylová Vranová et al, 2010; Aerts et al, 2011; Parnetti et al, 2011; van Dijk et al, 2013a) or decreased (Sjögren et al, 2002; Compta et al, 2009b; Mollenhauer et al, 2011; Shi et al, 2011; Kang et al, 2013; Nutu et al, 2013a; Vranová et al, 2014) CSF Aβ1-42 (Aβ1-42) in PD patients, with the exception of one study which reports increased levels (Parnetti et al, 2014b). Other found decreased CSF Aβ-1-42 (Mollenhauer et al, 2006; Compta et al, 2009b; Alves et al, 2010; Montine et al, 2010; Siderowf et al, 2010) and Aβ1-40 (Alves et al, 2010) and Aβ1-38 (Alves et al, 2010) only in PDD patients or in PD patients with memory impairment.…”