High‐Frequency Repetitive Transcranial Magnetic Stimulation on the Left Parietal Lobe Improves Post‐Stroke Memory Impairment: An fNIRS Study

BACKGROUND: Memory impairment is a prevalent cognitive deficit following stroke, which can significantly impact quality of life and rehabilitation prognosis. Traditional cognitive rehabilitation therapy offers some benefits in improving memory function, its efficacy remains limited. This study investigated the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) at the left parietal lobe on post-stroke memory impairment. METHODS: A total of 45 patients with post-stroke memory impairment were randomly divided into two groups. The rTMS group underwent 20 Hz rTMS on the left parietal lobe, while the non-stimulated control group received sham stimulation. All participants underwent neuropsychological tests (including the montreal cognitive assessment (MoCA), Rey auditory verbal learning test (RAVLT), and Rey-Osterrieth complex figure test (ROCF)) and functional near-infrared spectroscopy (fNIRS) scans before and after intervention. fNIRS data was analyzed by functional connectivity analysis to measure changes within brain networks. RESULTS: After treatment, the rTMS group showed greater improvement in MoCA scores compared to baseline (p < 0.05). Relative to the controls, the rTMS group demonstrated higher scores in delayed recall for RAVLT and ROCF (p < 0.05), as well as significantly enhanced resting-state functional connectivity (rsFC) within the prefrontal lobe and between the left prefrontal lobe and right occipital lobe (p < 0.05). CONCLUSIONS: High-frequency rTMS of the left parietal lobe effectively ameliorates memory impairment in stroke patients, and one of the possible mechanisms is the enhanced rsFC within the prefrontal lobe and between the prefrontal and occipital lobes.