In 2020, Transcranial Magnetic Stimulation (TMS) experts from around the world came together to publish a scientific paper on the safety of TMS. This huge undertaking involved dozens of leaders in the field, from over 10 different countries. Together they collated all of the existing literature involving TMS, and analysed the results of hundreds of thousands of treatments.
The focus of this study was to analyse the risk of adverse events occurring from TMS treatment, and to establish recommendations for minimising these. TMS is generally very safe, with the most severe risk being seizure. By combining the results of over 300,000 individual TMS sessions the authors found a total of 24 reports of seizure, however 19 of these were in high risk patients (with epilepsy or brain lesions), so when these people are excluded the total falls to five seizures in 300,000 treatments. This risk of <0.0001% compares very favourably to other interventions for fibromyalgia, such as anti-depressant drugs, which actually carry an estimated seizure risk of 0.37%.
The other serious risk that was identified was hearing sensitivity after treatment. Although the TMS machine does not sound loud, the proximity of the machine to the patient’s ear can actually mean that the noise produced can be enough to cause issues. This is very easily remedied, however, with the use of earplugs, and the only reported complaint in the literature was in a patient whose hearing protection had slipped out during their treatment. At TMS London we follow the very latest recommendations to ensure that our patients are as safe as possible, which of course includes the use of hearing protection.
No medical intervention is entirely without risk, but based on the latest review, TMS appears to be very safe and well tolerated. The non-invasive nature of the treatment, alongside the lack of side effects that are common with pharmaceutical interventions, make TMS an exciting option for people suffering with fibromyalgia.
 Rossi, S., Antal, A., Bestmann, S., Bikson, M., Brewer, C., Brockmöller, J., … & Hallett, M. (2020). Safety and recommendations for TMS use in healthy subjects and patient populations, with updates on training, ethical and regulatory issues: expert guidelines.
 Hill, T., Coupland, C., Morriss, R., Arthur, A., Moore, M., & Hippisley-Cox, J. (2015). Antidepressant use and risk of epilepsy and seizures in people aged 20 to 64 years: cohort study using a primary care database. BMC psychiatry, 15(1), 1-13.