Hypercapnia affects the functional coupling of resting state electroencephalographic rhythms and cerebral haemodynamics in healthy elderly subjects and in patients with amnestic mild cognitive impairment

A comprehensive assessment of resting state networks: bidirectional modification of functional integrity in cerebro-cerebellar networks in dementia

“…An alternative interpretation of increased gFC in both MCI and AD is that it represents, at least to some extent, hyper-synchrony and phase locking, thereby reducing mutual information transfer through network nodes (Borst and Theunissen, 1999). Consistent with this hypothesis is the finding of diffused increase of spectral power in the EEG delta band of AD patients, which is also index of disease progression (Babiloni et al, 2004, 2014). In this case, the hypothesis of a compensatory mechanism may be erroneous.…”

Cerebral Hemodynamics in Mild Cognitive Impairment: A Systematic Review

“…combining TCD and NIRS [47,56,57], eight NIRS only [58][59][60][61][62][63][64], five fMRI [15,[65][66][67] and two using PET or SPECT [20,40] (Table 1). Median quality score was 13/15.…”

“…All studies lacked sample size calculations, and few demonstrated testing for validity and reliability ( Supplementary Figures 1 and 2). Twenty-two of the 26 studies were cross sectional [15,18,20,40,47,48,[53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69], and the remaining four studies were longitudinal [50][51][52]60] (two mixed design) [52,60]. Follow-up time in the longitudinal studies ranged from five weeks to two years [50][51][52]60].…”

“…The diagnostic classification system used for MCI varied between studies, five had no formal criteria [18,20,47,53,68], the majority used the Petersen criteria (n = 14) [40,48,51,52,54,[56][57][58][59][60][61][62]67], and fewer used the Mayo [50,55], Winbald [65], Jak [15,64,69], and Reisberg [66] criteria. Several studies had extensive exclusion of other neurodegenerative, psychiatric conditions [15, 48, 50-52, 57-60, 62, 63, 66, 67] and psychotropic medications [59,62,67]. Some studies restricted their population to solely amnestic MCI [47, 51, 56-59, 65, 67].…”

Memory Assessment in the Clinical Context Using Functional Magnetic Resonance Imaging

“…In addition, the extent to which the microscopic pathology in mTLE or MCI/Alzheimer disease and the use of medications in these conditions may influence (either globally or locally) the neurovascular coupling that is crucial for observing the BOLD effect is not yet known. [100][101][102] Many of these influences will be difficult to estimate in smallscale studies, let alone the individual case. Finally, the essentially correlational methods involved in fMR imaging studies require convergent validation with other causal manipulations (eg, stimulation or inactivation, lesion) to increase confidence that activated regions are indeed essential to memory performance.…”