When examining the neuropsychological test scores between pMCI and sMCI, we found that patients with pMCI had a significantly lower ACE compared to patients with sMCI (see Table 3). Studies have previously found that neuropsychological tests (Maioli et al., 2007; Rozzini et al., 2008) and ACE (Galton et al., 2005; Mitchell et al., 2009) are able to predict the progression from MCI to AD. Furthermore, we found that global gamma/theta CFC was not significantly different between pMCI and AD. These findings may indicate that the included patients with pMCI were further downstream in the disease compared to patients with sMCI at the time of inclusion or that pMCI and sMCI comprised a fundamentally different underlying etiology. More studies are needed to investigate the potential of CFC as a marker of progression and potentially include patients at a very early stage of the disease.
