Transcranial Magnetic Stimulation for Migraine: A Safety Review

Objective.- To review potential and theoretical safety concerns of transcranial magnetic stimulation (TMS), as obtained from studies of single-pulse (sTMS) and repetitive TMS (rTMS) and to discuss safety concerns associated with sTMS in the context of its use as a migraine treatment. Methods.- The published literature was reviewed to identify adverse events that have been reported during the use of TMS; to assess its potential effects on brain tissue, the cardiovascular system, hormone levels, cognition and psychomotor tests, and hearing; to identify the risk of seizures associated with TMS; and to identify safety issues associated with its use in patients with attached or implanted electronic equipment or during pregnancy. Results.- Two decades of clinical experience with sTMS have shown it to be a low risk technique with promise in the diagnosis, monitoring, and treatment of neurological and psychiatric disease in adults. Tens of thousands of subjects have undergone TMS for diagnostic, investigative, and therapeutic intervention trial purposes with minimal adverse events or side effects. No discernable evidence exists to suggest that sTMS causes harm to humans. No changes in neurophysiological function have been reported with sTMS use. Conclusions.- The safety of sTMS in clinical practice, including as an acute migraine headache treatment, is supported by biological, empirical, and clinical trial evidence. Single-pulse TMS may offer a safe nonpharmacologic, nonbehavioral therapeutic approach to the currently prescribed drugs for patients who suffer from migraine.