Resting-state functional abnormalities in ischemic stroke: a meta-analysis of fMRI studies

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Ischemic stroke is a primary cause of global disability and mortality.
• The neural mechanisms underlying spontaneous brain activity fluctuations in stroke survivors are not fully understood.
• Resting-state brain activity patterns offer insights into neurological conditions.

Purpose of the Study:

• To investigate the neural mechanisms of resting-state brain activity in ischemic stroke.
• To identify consistent patterns of altered brain activity across multiple studies using meta-analysis.
• To explore potential imaging biomarkers for stroke recovery and plasticity.

Main Methods:

• A meta-analysis of 22 studies examining regional homogeneity (ReHo), amplitude of low-frequency fluctuation (ALFF), and fractional amplitude of low-frequency fluctuation (fALFF).
• Included data from 692 ischemic stroke patients and 620 healthy controls.
• Analyzed resting-state functional magnetic resonance imaging (fMRI) data.

Main Results:

• Decreased regional activity was observed in the bilateral caudate and thalamus.
• Increased regional activity was found in the left superior occipital gyrus and the left default mode network (precuneus/posterior cingulate cortex).
• Amplitude of low-frequency fluctuation studies indicated reduced activity in the left inferior frontal gyrus from acute to chronic stroke phases.

Conclusions:

• Disruptions in subcortical areas and the default mode network may represent core functional abnormalities in ischemic stroke.
• Altered brain activity in the inferior frontal gyrus could serve as an imaging indicator of neural recovery and plasticity post-stroke.
• These findings may inform the development of predictive models and therapeutic strategies for stroke rehabilitation.