Regional homogeneity abnormalities in patients with transient ischaemic attack: A resting-state fMRI study

• The regional homogeneity (ReHo) method was employed to investigate transient ischaemic attack (TIA)-related modulations of neural activity in the resting state.
• Altered regional spontaneous activities in dorsolateral prefrontal cortex (dlPFC) and inferior prefrontal cortex (iPFC) were found in TIAs, which were positively correlated with cognitive function in these patients.
• ReHo could be regarded as a promising tool to better our understanding of the neurobiological consequences of TIA.

ObjectiveTo investigate regional activity abnormalities in the resting state in patients with transient ischaemic attack (TIA) using a regional homogeneity (ReHo) method combined with functional magnetic resonance imaging (fMRI) and to examine the relationship between regional activity abnormalities and clinical variables.MethodsResting-state fMRI was conducted in 21 patients with right-sided TIA and in 21 healthy volunteers. The ReHo was calculated to assess the strength of the local signal synchrony and was compared between the two groups.ResultsCompared with the controls, the TIA patients exhibited a decreased ReHo in the right dorsolateral prefrontal cortex (dlPFC), the right inferior prefrontal cortex (iPFC), the right ventral anterior cingulate cortex (vACC) and the right dorsal posterior cingulate cortex (dPCC). In addition, the mean ReHo values in the right dlPFC and the right iPFC were significantly correlated with the Montreal Cognitive Assessment (MoCA) in TIA patients.ConclusionsNeural activities in the resting state are changed in TIA patients even without visible ischaemic lesions on conventional MRI. The positive correlation between the ReHo of resting-state fMRI and cognition suggests that ReHo could be a promising tool to observe the neurobiological consequences of TIA.SignificanceThe present study revealed abnormal local synchronisation of spontaneous neural activities in patients with TIA.