Capturing Neuroplastic Changes after iTBS in Patients with Post-Stroke Aphasia: A Pilot fMRI Study

Area of Science:

• Neuroscience
• Neurology
• Rehabilitation Medicine

Background:

• Post-stroke aphasia (PSA) presents significant communication challenges.
• Intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation (TMS) technique, is explored for PSA treatment.
• The precise mechanisms underlying iTBS efficacy in PSA remain unclear.

Purpose of the Study:

• To investigate the immediate effects of iTBS on the primary motor cortex (M1) in patients with PSA.
• To examine changes in functional brain activity and connectivity following iTBS intervention.
• To explore potential neuroplasticity mechanisms induced by iTBS.

Main Methods:

• 16 patients with post-stroke aphasia underwent iTBS (800 pulses, 300 s) targeting the affected hemisphere's M1.
• Comprehensive motor, language, and cognitive assessments were performed.
• Resting-state functional MRI was used to analyze brain activity (fALFF) and connectivity (DC, FC) before and after iTBS.

Main Results:

• Significant alterations in fALFF, DC, and FC values were observed post-iTBS.
• Increased DC in the right middle frontal gyrus and left parietal lobe.
• Decreased fALFF in the right medial frontal lobe and left intracalcarine cortex.
• Reduced functional connectivity between the left M1 and left superior frontal gyrus.

Conclusions:

• Single-session iTBS on the ipsilesional M1 induces immediate changes in neural activity and functional connectivity in PSA patients.
• These neurophysiological changes may contribute to neuroplasticity and functional recovery.
• Further research is warranted to confirm these preliminary findings and optimize iTBS protocols.