While there is good evidence for altered resting-state networks, particularly the default mode network (DMN), in both Alzheimer's disease (AD) and amnestic mild cognitive impairment preceding AD, there are rather conflicting data on changes in the DMN in Parkinson's disease (PD) and PD with cognitive impairment. This paper will focus on DMN study results, particularly in PD, as assessed by functional MRI.

• MeSH
• Alzheimerova nemoc patofyziologie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mozek patofyziologie   MeSH
• nervové dráhy fyziologie   MeSH
• odpočinek fyziologie   MeSH
• Parkinsonova nemoc patofyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

BACKGROUND: Cognitive impairment in Parkinson's disease (PD) is associated with altered connectivity of the resting state networks (RSNs). Longitudinal studies in well cognitively characterized PD subgroups are missing. OBJECTIVES: To assess changes of the whole-brain connectivity and between-network connectivity (BNC) of large-scale functional networks related to cognition in well characterized PD patients using a longitudinal study design and various analytical methods. METHODS: We explored the whole-brain connectivity and BNC of the frontoparietal control network (FPCN) and the default mode, dorsal attention, and visual networks in PD with normal cognition (PD-NC, n = 17) and mild cognitive impairment (PD-MCI, n = 22) as compared to 51 healthy controls (HC). We applied regions of interest-based, partial least squares, and graph theory based network analyses. The differences among groups were analyzed at baseline and at the one-year follow-up visit (37 HC, 23 PD all). RESULTS: The BNC of the FPCN and other RSNs was reduced, and the whole-brain analysis revealed increased characteristic path length and decreased average node strength, clustering coefficient, and global efficiency in PD-NC compared to HC. Values of all measures in PD-MCI were between that of HC and PD-NC. After one year, the BNC was further increased in the PD-all group; no changes were detected in HC. No cognitive domain z-scores deteriorated in either group. CONCLUSION: As compared to HC, PD-NC patients display a less efficient transfer of information globally and reduced BNC of the visual and frontoparietal control network. The BNC increases with time and MCI status, reflecting compensatory efforts.

• MeSH
• dospělí MeSH
• kognitivní dysfunkce etiologie   patologie   psychologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• longitudinální studie MeSH
• magnetická rezonanční tomografie MeSH
• mozek diagnostické zobrazování   patologie   MeSH
• nervová síť diagnostické zobrazování   patologie   MeSH
• neurozobrazování MeSH
• Parkinsonova nemoc komplikace   patologie   psychologie   MeSH
• prefrontální mozková kůra patologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• temenní lalok patologie   MeSH
• testy pro posouzení mentálních funkcí a demence MeSH
• zrakové korové centrum patologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The default mode network (DMN) decreases its activity when switching from a resting state to a cognitive task condition, while activity of the network engaged in the given task increases. Visual processing is typically disturbed in Parkinson's disease dementia (PDD). OBJECTIVE: Using functional MRI, we studied the DMN effective connectivity patterns in PDD as compared with cognitively normal patients with Parkinson's disease (PD) and healthy controls (HC) when switching from baseline to a visual cognitive task condition. METHODS: In all, 14 PDD, 18 PD, and 18 age-matched healthy controls participated in this functional MRI study. We used a psychophysiological interaction analysis with the precuneus (PCu) as a seed. The threshold was set at p(FWE) <0.05. RESULTS: The healthy controls showed greater PCu connectivity with the bilateral middle temporal/middle occipital gyri at baseline than during the task condition. The correlation direction changed from positive to negative. Both PD and PDD showed disturbed DMN connectivity with the brain regions that are involved in bottom-up visual processing. In PD, we also found impaired integration of the areas engaged in the ventral attentional network, which might reflect specific attentional deficits observed during the early course of PD. In mild PDD, we detected increased engagement of areas involved in the dorsal attentional network, which corresponds to increased top-down control in this patient group as compared to the healthy controls. CONCLUSION: Our results show impaired dynamic interplay between large scale brain networks in PD that spread far beyond the motor system.

• MeSH
• atrofie etiologie   patologie   MeSH
• hyperkinetická porucha etiologie   MeSH
• kognitivní poruchy etiologie   patologie   MeSH
• kyslík krev   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mapování mozku MeSH
• modely neurologické MeSH
• nervové dráhy krevní zásobení   patologie   MeSH
• neuropsychologické testy MeSH
• Parkinsonova nemoc komplikace   patologie   MeSH
• počítačové zpracování obrazu MeSH
• poruchy zraku etiologie   patologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• světelná stimulace MeSH
• temenní lalok krevní zásobení   patologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH