Subacute default mode network dysfunction in the prediction of post-stroke depression severity.

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Stroke can lead to significant psychological distress, including depression and anxiety.
• The default mode network (DMN) plays a crucial role in emotional regulation and self-referential processing.
• Understanding the neural underpinnings of post-stroke mood disorders is essential for developing effective interventions.

Purpose of the Study:

• To investigate resting-state functional connectivity (FC) patterns within the DMN in the early period after stroke.
• To determine if the strength of DMN FC predicts the severity of depression and anxiety symptoms post-stroke.
• To identify specific brain regions within the DMN whose FC is associated with post-stroke mood disturbances.

Main Methods:

• 24 first-stroke patients without prior psychiatric history underwent resting-state fMRI 10 days post-stroke.
• Independent component analysis was used to isolate the DMN.
• Depression (HDRS-17) and anxiety (HARS) severity were assessed at 10 days and 3 months post-stroke.
• Whole-brain statistical parametric mapping was employed to analyze associations between DMN FC and symptom severity, adjusting for covariates.

Main Results:

• Anxiety severity correlated with FC in the middle temporal cortex and anterior midcingulate cortex at 10 days post-stroke.
• At 3 months, anxiety correlated with FC in the middle temporal cortex and posterior cingulate cortex.
• Depression severity did not correlate with FC at 10 days but was associated with FC in the left middle temporal cortex and precuneus at 3 months.

Conclusions:

• Dysfunction in DMN functional connectivity, particularly in areas involved in emotional control, is linked to the severity of post-stroke depression.
• These findings suggest that DMN alterations may serve as a biomarker for predicting and understanding post-stroke mood disorders.
• Further research is needed to elucidate the mechanisms underlying these functional impairments and to explore therapeutic strategies targeting the DMN.