Parkinson’s Disease–Mild Cognitive Impairment (PD-MCI): A Useful Summary of Update Knowledge

Abstract

Mild cognitive impairment (MCI) is a common feature in Parkinson’s Disease (PD), even at the time of diagnosis. Some levels of heterogeneity in nature and severity of cognitive impairment and risk of conversion to Parkinson’s Disease Dementia (PDD) exist. This brief overview summarized the current understanding of MCI in PD, by considering the following major points: historical development of the clinical entity, evaluation, epidemiology, predictors and outcomes, neuroimaging findings, pathophysiology, treatment, and pharmacological and non-pharmacological intervention. MCI in PD represents a concept in evolution and plays a pivotal role in advancing our understanding of the disease mechanisms, with the ultimate goal of building effective strategies to prevent conversion into PDD. Challenges for future research are also discussed.

Investigating the relationship between the SNCA gene and cognitive abilities in idiopathic Parkinson’s disease using machine learning

“…The number of years of education was also found to be predictive of global cognition in our cohort. Similarly, a large body of evidence reported a negative correlation between higher education level and the likelihood of cognitive impairments in PD patients 4 , 30 , 33 . It has been suggested that education has a role in preserving the cognitive reserve in PD patients at risk of cognitive decline 46 .…”

“…There is a substantial body of evidence on the role of sex in cognitive decline in PD, with male patients showing greater risk of cognitive impairments 30 – 32 . However, it also needs to be mentioned that several other studies reported no evidence of the impact of sex in cognitive decline in PD 4 , 33 . The reason for these conflicting results remains speculative but could be related to the sample size.…”

“…The structural biomarkers of cognitive decline in PD have been investigated extensively using different techniques 33 , 47 , 48 . The right parahippocampal gyrus, the top anatomical feature identified in this study, has been reported as one of the main brain regions showing significant Dopamine receptor (D2) binding reduction in PD patients 49 .…”

Circulating Exosome microRNAs as Diagnostic Biomarkers of Dementia

“…Unlike AD, the diagnostic criteria of PDD do not emphasize memory impairment but place more emphasis on the impairment of the patients’ cognitive domain. Due to the complex clinical manifestations of this disease, there is an urgent need for PDD diagnostic biomarkers (Cammisuli et al, 2019 ). Presently, research on the differential expression of circulating ex-miRNAs as biomarkers has mainly focused on those with a PD diagnosis.…”

Impact of cognitive intervention on cognitive symptoms and quality of life in idiopathic Parkinson’s disease: a randomized and controlled study

“…Patients who present deficits in semantic language, figure drawing/copying and visuospatial tasks have a higher risk to develop dementia. 6,7 Although PD is considered a motor control disorder, deterioration in cognitive functions is a common complication, occurring in approximately 40% of cases. Half of the patients without dementia have MCI, and such changes can impair the patient's quality of life, as well as being a risk factor for the development of dementia.…”