Neurovascular coupling dysfunction of the frontal‒thalamic circuit in postconcussion syndrome

Area of Science:

• Neuroscience
• Medical Imaging
• Systems Biology

Background:

• Postconcussion syndrome (PCS) involves altered brain activity and blood flow, especially in the frontal-thalamic circuit.
• Understanding dynamic network interactions in PCS is crucial for explaining cognitive and behavioral impairments.

Purpose of the Study:

• To investigate neurovascular coupling (NVC) and functional network alterations in the frontal-thalamic circuit of individuals with PCS.
• To identify specific connectivity changes underlying cognitive dysfunction in PCS.

Main Methods:

• Recruited 38 participants with PCS and 38 healthy controls for magnetic resonance imaging.
• Analyzed NVC using amplitude of low-frequency fluctuation (ALFF), fractional ALFF, regional homogeneity, and degree centrality.
• Applied dynamic causal modeling (DCM) to assess functional network connectivity and spectral DCM for NVC analysis.

Main Results:

• Reduced excitatory cortical connectivity was found from the left thalamus to the left middle frontal gyrus and right thalamus to right middle frontal gyrus.
• Decreased inhibitory cortical connectivity was observed from the right middle frontal gyrus to the right thalamus.
• Increased excitatory cortical connectivity from the left putamen to the left middle frontal gyrus suggests a potential compensatory mechanism.

Conclusions:

• Altered neurovascular coupling in the frontal-thalamic circuit is a distinctive feature of PCS.
• These connectivity changes likely contribute to the executive and cognitive dysfunctions observed in postconcussion syndrome.