Frontoamygdala hyperconnectivity predicts affective dysregulation in adolescent moderate-severe TBI

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Affective disruptions are common in moderate to severe traumatic brain injury (msTBI) survivors but often undertreated due to poorly understood neural mechanisms.
• Limbic circuits are hypothesized to play a crucial role in affective dysregulation following msTBI.

Purpose of the Study:

• To investigate the relationship between amygdala resting-state functional connectivity (rsfMRI) networks and affective problems in adolescents with msTBI.
• To determine if specific amygdala network connectivity patterns predict externalizing and internalizing behaviors.

Main Methods:

• Studied 19 adolescents with msTBI and 44 healthy controls (HC) using rsfMRI.
• Analyzed connectivity within two predefined amygdala networks.
• Correlated network connectivity strength with parent-reported behavioral problems (e.g., BRIEF, CBCL) and cognitive function.

Main Results:

• Medial amygdala connectivity predicted externalizing behaviors (48% variance), localized to rostral anterior cingulate (rACC) and posterior cingulate (PCC) cortices.
• Ventrolateral amygdala connectivity predicted internalizing behaviors (57% variance), localized to ventromedial prefrontal cortex (vmPFC).
• Findings were specific to the msTBI group and independent of injury severity, time since injury, and other neuroimaging metrics.

Conclusions:

• Frontoamygdala pathways, specifically distinct amygdala networks, are implicated in chronic behavioral and mood dysregulation after msTBI.
• These neural pathways differentially predict externalizing and internalizing problems, offering targets for future neuromodulation therapies.
• Understanding these brain-behavior relationships is crucial for improving detection and treatment of affective disruptions in msTBI survivors.