Neuroprotection of Low-Frequency Repetitive Transcranial Magnetic Stimulation after Ischemic Stroke in Rats

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Stroke is a major cause of death and disability worldwide.
• Effective acute treatments with a viable therapeutic window are crucial for improving stroke outcomes.
• Transcranial magnetic stimulation (TMS) is a noninvasive technique with potential for treating brain disorders, but its acute neuroprotective effects in ischemic stroke are understudied.

Purpose of the Study:

• To investigate the efficacy of low-frequency repetitive transcranial magnetic stimulation (rTMS) as an acute neuroprotective treatment following ischemic stroke.
• To determine the optimal therapeutic window for rTMS administration after stroke onset.

Main Methods:

• Adult male rats underwent focal ischemic stroke induced by middle cerebral artery occlusion.
• Animals received either rTMS or sham treatment at varying delays (1.5, 3, 4, or 7 hours) post-stroke.
• Low-frequency, low-intensity rTMS was administered in two 30-minute sessions with a 1-hour interval.

Main Results:

• rTMS treatment at 1.5, 3, or 4 hours post-stroke significantly reduced infarct volume and cell death compared to controls.
• Neuroprotection was associated with upregulation of Bcl-2 and downregulation of caspase-3 cleavage, Bax, and MMP-9.
• Sensorimotor function was significantly improved in rats treated with rTMS at 1.5 or 3 hours post-stroke.

Conclusions:

• Low-frequency rTMS demonstrates feasibility and efficacy as an acute neuroprotective treatment for ischemic stroke.
• Early intervention with rTMS, particularly within a 4-hour window, offers significant therapeutic benefits.
• rTMS holds potential for clinical application in managing acute ischemic stroke.