Aberrantly higher functional connectivity in the salience network is associated with transient global amnesia

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Medical Imaging

Background:

• The salience network (SN), default mode network (DMN), and central executive network (CEN) are crucial for human cognition.
• Transient global amnesia (TGA) is a condition characterized by temporary memory loss.
• Understanding TGA's pathophysiology may benefit from examining intrinsic brain networks.

Purpose of the Study:

• To investigate alterations in intrinsic brain networks (SN, DMN, CEN) in patients with TGA.
• To explore the temporal dynamics of these network changes following TGA onset.

Main Methods:

• Resting-state functional magnetic resonance imaging (rsfMRI) was performed on 50 TGA patients and 25 healthy controls.
• rsfMRI scans were acquired within 24 hours, at 72 hours, and 3 months after TGA onset.
• Functional connectivity analysis was conducted on the SN, DMN, and CEN.

Main Results:

• Within 24 hours of TGA onset, patients exhibited increased SN connectivity and decreased DMN connectivity, with preserved CEN connectivity.
• At 72 hours, DMN connectivity remained decreased, while SN connectivity showed no significant alterations.
• By 3 months post-onset, functional connectivity in both SN and DMN returned to normal levels.

Conclusions:

• TGA is associated with transient alterations in intrinsic brain network connectivity, specifically increased SN and decreased DMN connectivity.
• These network changes are temporary and normalize over time.
• The findings offer insights into the neurobiological underpinnings of TGA pathophysiology.