Repetitive Transcranial Magnetic Stimulation Improves Cognitive Impairment via the Regulation of White Matter Injury in Rats With Ischemic Stroke.

PURPOSE: Poststroke cognitive impairment (PSCI) is a common functional disorder that occurs following stroke, but there are few effective therapies. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulatory technique that has been used to improve cognitive function in stroke patients. Despite its widespread use in clinical research, the underlying mechanisms of rTMS are largely unknown. This study hypothesized that rTMS ameliorates PSCI by regulating white matter injury, which is of vital importance in cerebral ischemia. METHOD: An ischemic stroke rat model was created using transient middle cerebral artery occlusion. The extents of brain damage and white matter injury, including diffusion tensor imaging and diffusion tensor tractography, were evaluated using MRI. Behavioral tests, including the modified neurological severity score test and Morris water maze test, were also used. In addition, we preliminarily explored the potential role of SDF-1α/CXCR4 by Western blot analysis and real-time reverse transcription PCR. FINDING: The results showed that 10 Hz rTMS promoted neurological recovery and cognitive deficits in ischemic rats. Additionally, 10 Hz rTMS alleviated cerebral infarct severity and attenuated white matter lesions. Furthermore, the expression levels of components of the SDF-1α/CXCR4 axis influenced the effect of rTMS on ischemic stroke. CONCLUSION: This research provides further evidence that 10 Hz rTMS can alleviate white matter injury in affected brain regions and improve PSCI after ischemic stroke, potentially through the activation of the SDF-1α/CXCR4 axis.