This article is based on a consensus conference, which took place in Certosa di Pontignano, Siena
(Italy) on March 7-9, 2008, intended to update the previous safety guidelines for the application of
transcranial magnetic stimulation (TMS) in research and clinical settings.
Over the past decade the scientific and medical community has had the opportunity to evaluate the
safety record of research studies and clinical applications of TMS and repetitive TMS (rTMS). In these
years the number of applications of TMS has grown impressively, new paradigms of stimulation have
been developed (e.g. arrhythmic rTMS) and technical advances have led to new device designs and
to the real-time integration of TMS with electronencephalography (EEG), positron emission
tomography (PET) and functional magnetic resonance imaging (fMRI). Thousands of healthy subjects
and patients with various neurological and psychiatric diseases have undergone TMS allowing to
better assess relative risks. The occurrence of seizures (i.e., the most serious TMS-related acute
adverse effect) has been extremely rare, with most of the few new cases receiving TMS protocols
exceeding previous guidelines, often in patients under treatment with drugs which potentially lower the
The present updated guidelines review issues of risk and safety of conventional TMS protocols,
address the undesired effects and risks of emerging TMS interventions, the applications of TMS in
patients with implanted brain electrodes, and safety aspects of TMS in neuroimaging environments.
We cover recommended limits of stimulation parameters and other important precautions, monitoring
of subjects, expertise of the rTMS team, and ethical issues. While all the recommendations here are
expert based, they utilize published data to the extent possible.
A Consensus Statement from the International Workshop on “Present and Future of TMS: Safety and Ethical Guidelines”, Siena, March 7-9, 2008 Simone Rossi1, Mark Hallett2, Paolo M. Rossini3 and Alvaro Pascual Leone4