Navigated Transcranial Magnetic Stimulation for Preoperative Neurosurgical Mapping

Navigated transcranial magnetic stimulation (nTMS) is a noninvasive method of mapping functional cortical areas before neurosurgery. The Nexstim navigated brain stimulation system integrates transcranial magnetic stimulation with magnetic resonance imaging (MRI)-based neuronavigation to localize motor or language-related cortical sites. Mapping data may be exported for surgical planning, neuronavigation, and diffusion tensor imaging tractography. In individuals with brain tumors involving or near eloquent cortex, the clinical purpose is to improve preoperative risk assessment, guide the surgical approach, and support maximal safe resection while reducing permanent neurologic deficits.