We hypothesized that TGA could be related to functional changes of intrinsic brain network, especially in default mode network (DMN) and salience network (SN). 

A total of 50 patients with TGA who agreed to participate in this study and underwent resting-state functional magnetic resonance imaging (rsfMRI) within 24 hours of symptom onset. At 72 hours, 50 patients with TGA followed up MRI scan and a total of 22 patients with TGA followed up the MRI scan after 3 months of symptom onset. We also recruited 25 healthy controls with normal cognitive functions. The MELODIC software (FSL 5.1) was used to analyze independent component analysis for detecting intrinsic brain network. Multiple comparisons were corrected using Monte Carlo simulation with 10,000 iterations implemented in the AFNI's AlphaSim software. The threshold of a combination of a voxelwise P < 0.01 and a cluster size of at least 376 mm³ was used to correct for multiple comparisons at p < 0.05.

Compared to normal control, TGA patients showed higher functional activity in the SN but relatively lower functional activities in DMN during acute phase of TGA symptoms. Interestingly, TGA patients still showed lower functional activities in the DMN until 72 hours of symptom onset, while functional activities in the SN were normalized at the 72 hours of symptom onset. Those alterations in DMN and SN were recovered at the follow-up scans after 3 months of symptom onset in patients with TGA.