Limbic pathway vulnerability associates with neurologic outcome in children after cardiac arrest

Area of Science:

• Neuroscience
• Radiology
• Pediatric Critical Care

Background:

• Pediatric cardiac arrest (PCA) can lead to significant neurologic deficits.
• Identifying biomarkers for predicting neurologic outcome after PCA is crucial for timely intervention.

Purpose of the Study:

• To investigate if brain connectivity patterns, assessed by DTI and rsfMRI, can identify brain regions and networks associated with neurologic outcomes in pediatric patients following cardiac arrest.
• To correlate specific DTI and rsfMRI measures with the severity of neurologic impairment.

Main Methods:

• Children aged 2 days to 17 years who experienced cardiac arrest underwent clinically indicated brain MRI, including DTI and rsfMRI, within two weeks post-arrest.
• Tract-wise fractional anisotropy (FA) and diffusivity measures from DTI, and functional connectivity strength (FCS) from rsfMRI were analyzed.
• Neurologic outcome was categorized as unfavorable based on the Pediatric Cerebral Performance Category (PCPCS) score or change from baseline at 6 months.

Main Results:

• Diffusion tensor imaging (DTI) analysis in 28 children revealed associations between altered diffusivity and FA in limbic tracts (e.g., cingulum, corpus callosum) and unfavorable neurologic outcomes (p < 0.05).
• Resting state functional magnetic resonance imaging (rsfMRI) analysis in 12 children showed decreased functional connectivity strength (FCS) in prefrontal cortex, insula, and other regions correlated with unfavorable outcomes (p < 0.05, Family-Wise Error corrected).

Conclusions:

• Multimodal brain connectivity measures, particularly in paralimbic tracts, are associated with neurologic outcomes following pediatric cardiac arrest.
• Further longitudinal studies correlating brain connectivity with long-term neuropsychological outcomes are warranted to understand the impact on vulnerable brain networks over time.