Can Neuroimaging Predict Dementia in Parkinson's Disease?

Juliette H. Lanskey; Peter McColgan; Anette E. Schrag; Julio Acosta-Cabronero; Geraint Rees; Huw R. Morris; Rimona S. Weil


Brain. 2018;141(9):2545-2560. 

In This Article

Resting State Functional MRI

Resting state functional MRI (rs-fMRI) measures blood oxygen level-dependent signal fluctuations when participants are at rest. One method to identify signals obtained in such circumstances related to particular networks is to use independent component analysis (ICA), a technique that mathematically separates rs-fMRI data into independent components. ICA analysis of rs-fMRI data in brain networks may be sensitive to differences in cognitive performance. The most studied is the default mode network (DMN). DMN connectivity within medial and lateral occipito-parietal regions was increased in patients with PD-MCI compared to patients without cognitive impairment (Baggio et al., 2015). This is at odds with most other studies of DMN connectivity in Parkinson's dementia, which generally show reduced functional connectivity (Tessitore et al., 2012; Yao et al., 2014; Karunanayaka et al., 2016), and may be accounted for by differences in levodopa, which can alter DMN connectivity (Krajcovicova et al., 2012) or may reflect compensatory changes. Interestingly, increased connectivity was correlated with poorer visuo-perceptual scores (Baggio et al., 2015), consistent with importance of loss of visuo-perceptual function early in Parkinson's-associated dementia.