High-frequency repetitive transcranial magnetic stimulation attenuates white matter damage and improves functional recovery in rats with ischemic stroke

Abstract

Stroke is a major cause of acquired disability and the second most frequent cause of dementia, while specific therapeutic rehabilitation strategies remain limited. Repetitive transcranial magnetic stimulation(rTMS) is a well-known rehabilitation modality after cerebral ischemic injury. White matter damage is an important contributor to motor and cognitive dysfunctions after stroke. This study aimed to evaluate the effect of rTMS on white matter recovery and neurological deficits in ischemic stroke. Grip strength test and novel object recognition test were conducted to assess motor and cognitive functions after middle cerebral artery occlusion(MCAO). MRI, including Diffusion tensor imaging (DTI) and Diffusion Tensor Tractography (DTT) were performed to evaluate white matter injury in MCAO rats. Moreover, Western blotting were detected to observe related myelin damage proteins in the ischemic brain. The results revealed that 10 Hz rTMS alleviated the motor and cognitive deficits in rats after ischemic surgery. Besides, the data from DTI and DTT showing that 10 Hz rTMS ameliorated the white matter lesion of rats after cerebral ischemia. In addition, 10 Hz rTMS attenuated significant loss of the myelin sheath by enhanced myelin associated proteins levels in the ischemic brain of ischemic rats. These findings suggest that 10 Hz rTMS exerted therapeutic neuroprotective properties after ischemic stroke, in a manner that may be associated with enhancing structural repairment of the white matter, which may provide a potential therapeutic strategy for ischemic stroke.