Epistaxis during a single-pulse Transcranial Magnetic Stimulation session: A previously unreported side effect

Transcranial magnetic stimulation (TMS) is a neurostimulation and neuromodulation technique, based on the principle of electromagnetic induction in the brain of an electric field which can be of sufficient magnitude and density to depolarize neurons [1]. The most robust and widely accepted use is in measuring the connection between the primary motor cortex and a muscle, but TMS also represents a useful non-invasive approach for studying cortical physiology. Moreover, if delivered repetitively, TMS can also alter brain function beyond the time of stimulation, and has therefore therapeutic potential [2].

Treatment with TMS is generally safe and well tolerated; the most common side effects are headache and discomfort at the stimulation site and the most serious but rare adverse effects are seizures [3]. The adverse effects correlate positively with both intensity and frequency of stimulation. We report here on two subjects who experienced epistaxis during a session of single-pulse TMS. To date, there is no reported association of TMS with epistaxis.