Is Neuroinflammation Involved in the Development of Dementia in Patients with Parkinson's Disease?

Objective High-sensitivity C-reactive protein (hs-CRP) is an extremely sensitive systemic marker of inflammation and tissue damage, and increased levels of hs-CRP are strongly associated with inflammatory reactions. Microglia-mediated neuroinflammation has been hypothesized to play an important role in the pathogenesis of idiopathic Parkinson's disease (PD). However, the clinical value of the hs-CRP level in patients with PD is poorly defined. Therefore, we conducted this study to analyze the differences in the hs-CRP levels in PD patients with and without dementia. Methods We examined 72 PD patients without dementia (PDwoD) and 45 PD patients with dementia (PDD), as well as 84 control subjects. We investigated the differences in the hs-CRP and fibrinogen levels between these three groups. Results The mean hs-CRP and fibrinogen values were not significantly different between the PDwoD and PDD groups; however, these two groups had significantly higher mean hs-CRP and fibrinogen values than the control group. Conclusion It is known that inflammation plays a role in the pathogenesis of PD and dementia. However, based on the results of this study, we cautiously speculate that although neuroinflammation plays a role in the development of neurodegenerative diseases, including PD and dementia, it may be unrelated to the pathogenesis of dementia in patients with PD.