Changes in connectivity of the posterior default network node during visual processing in mild cognitive impairment: staged decline between normal aging and Alzheimer’s disease
- 319 Downloads
Visual processing difficulties are often present in Alzheimer’s disease (AD), even in its pre-dementia phase (i.e. in mild cognitive impairment, MCI). The default mode network (DMN) modulates the brain connectivity depending on the specific cognitive demand, including visual processes. The aim of the present study was to analyze specific changes in connectivity of the posterior DMN node (i.e. the posterior cingulate cortex and precuneus, PCC/P) associated with visual processing in 17 MCI patients and 15 AD patients as compared to 18 healthy controls (HC) using functional magnetic resonance imaging. We used psychophysiological interaction (PPI) analysis to detect specific alterations in PCC connectivity associated with visual processing while controlling for brain atrophy. In the HC group, we observed physiological changes in PCC connectivity in ventral visual stream areas and with PCC/P during the visual task, reflecting the successful involvement of these regions in visual processing. In the MCI group, the PCC connectivity changes were disturbed and remained significant only with the anterior precuneus. In between-group comparison, we observed significant PPI effects in the right superior temporal gyrus in both MCI and AD as compared to HC. This change in connectivity may reflect ineffective “compensatory” mechanism present in the early pre-dementia stages of AD or abnormal modulation of brain connectivity due to the disease pathology. With the disease progression, these changes become more evident but less efficient in terms of compensation. This approach can separate the MCI from HC with 77% sensitivity and 89% specificity.
KeywordsDementia fMRI Posterior cingulate Precuneus Psychophysiological interactions Visual pathways
This research was carried out under the project CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth and Sports of the Czech Republic under the National Sustainability Programme II. We acknowledge the core facility MAFIL of CEITEC supported by the Czech-BioImaging large RI project (LM2015062 funded by Ministry of Education, Youth and Sports of the Czech Republic) for their support with obtaining scientific data presented in this paper.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Albert MS et al (2011) The diagnosis of mild cognitive impairment due to Alzheimer’s disease: Recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement 7:270–279. doi: 10.1016/j.jalz.2011.03.008 CrossRefPubMedPubMedCentralGoogle Scholar
- Alescio-Lautier B, Michel BF, Herrera C, Elahmadi A, Chambon C, Touzet C, Paban V (2007) Visual and visuospatial short-term memory in mild cognitive impairment and Alzheimer disease: role of attention. Neuropsychologia 45:1948–1960. doi: 10.1016/j.neuropsychologia.2006.04.033 CrossRefPubMedGoogle Scholar
- Berankova D, Janousova E, Mrackova M, Eliasova I, Kostalova M, Skutilova S, Rektorova I (2015) Addenbrooke’s cognitive examination and individual domain cut-off scores for discriminating between different cognitive subtypes of Parkinson’s disease. Parkinsons Dis. doi: 10.1155/2015/579417 PubMedPubMedCentralGoogle Scholar
- Hummelová-Fanfrdlová Z et al (2009) Czech adaptation of Addenbrooke’s cognitive examination. Ceskoslovenska Psychol 53:376–388Google Scholar
- Lundstrom BN, Petersson KM, Andersson J, Johansson M, Fransson P, Ingvar M (2003) Isolating the retrieval of imagined pictures during episodic memory: activation of the left precuneus and left prefrontal cortex. Neuroimage 20:1934–1943. doi: 10.1016/j.neuroimage.2003.07.017 CrossRefPubMedGoogle Scholar
- McKhann GM et al (2011) The diagnosis of dementia due to Alzheimer’s disease: Recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement 7:263–269. doi: 10.1016/j.jalz.2011.03.005 CrossRefPubMedPubMedCentralGoogle Scholar