Depression Affects Intrinsic Brain Activity in Patients With Mild Cognitive Impairment

Abstract

Numerous observational studies have shown that depressive symptoms are common in individuals with mild cognitive impairment (MCI) who have a higher rate of progress to dementia. However, it is still uncertain whether there are any differences between MCI patients with and without depression symptom in their brain function activities. Here we have identified the brain function activity differences in two groups of MCI patients (with depression or without depression) using the resting state MRI (rsfMRI) measurements. 76 right-handed MCI subjects have been recruited in this study, including 27 MCI patients with depression symptom (MCID), 49 MCI patients without depression symptom (MCIND). Analyses based on 7 rsfMRI measurements, including four static measurements (ALFF, fALFF, PerAF, and ReHo) and three dynamic measurements (dALFF, dfALFF, and dReHo) have been used to explore the temporal variability of intrinsic brain activity. No significant differences in ALFF and dALFF between the two group were found. In the MCID group, fALFF decreased in temporal gyrus, frontal gyrus, inferior occipital gyrus, middle frontal gyrus and cerebellum, but increased in cuneus, calcarine, lingual; while PerAF increased in left parahippocampus. The differences of ReHo in the two groups was only found in cerebellum. Compared to MCIND group, dfALFF in MCID decreased in cuneus, occipital gyrus and calcarine, while dReHo in MCID increased in bilateral temporal gyrus, frontal gyrus, superior parietal gyrus, inferior parietal gyrus and precuneus. Our results may provide a better understanding in the relationship between the depressive symptoms and memory deficits.

Temporal dynamic changes of intrinsic brain activity in Alzheimer’s disease and mild cognitive impairment patients: a resting-state functional magnetic resonance imaging study

“…Based on the ALFF and fALFF maps, the mean and standard deviation were calculated for each voxel, and the standard deviation was divided by the mean to obtain the corresponding coefficient of variation (CV). The CV was used as the dALFF/dfALFF for more accurate temporal variability of absolute energy consumption in low-frequency regional brain activity between different individuals (24).…”

“…The dynamic ALFF (dALFF) and dynamic fALFF (dfALFF) methods are recommended for measuring the variance of ALFF and fALFF over time. The dALFF and dfALFF methods provide a new way to show local brain activity during scanning (22), and dALFF has been applied in patients with schizophrenia, anxiety, depression, and sleep disturbance (20,21,23,24). However, further research on abnormal dynamic local brain activity in AD and MCI patients is required.…”

Altered Dynamic Neural Activity in the Default Mode Network in Lung Cancer Patients After Chemotherapy

“…It is widely used to study cognitive decline in neural and mental illnesses, and there is increasing evidence reporting on close ties between rs-fMRI findings and cognitive function. An advantage of rs-fMRI is the short time required during scanning, making it more likely to be tolerable for lung cancer patients undergoing CTx [13,14]. Rs-fMRI can identify local activity in brain tissue, as well study the activity of neurons by looking at the effect of blood oxygen level dependence (BOLD) [15].…”

Functional plasticity abnormalities over the lifespan of first-episode patients with major depressive disorder: a resting state fMRI study

“…The significantly reduced node degree and activity have been widely observed in the calcarine, cuneus, and precuneus (44). Additionally, the fALFF in the cuneus, occipital gyrus, and calcarine were decreased by depressive symptoms in patients with mild cognitive impairment (45). As a key hub of DMN, the precuneus was recruited in visual imagery, episodic memory, and self-directed operations, and has consistently been reported to be a neural basis of depression (44).…”