Safety of TMS / rTMS

An initial report of the conference in Bethesda, MD, USA

By Saxby Pridmore, MD, of the TMS-POD group.

There were about 45 participants and attendees, from USA, Spain, Italy, Denmark, Israel, Germany, Japan and Australia. Representatives from both Dantec (Denmark) and Magstim (England) were also present.

The organisers were Dr Mark Hallett and Dr Eric Wassermann, both of the NINDS. An official report of the agreed findings will appear in due course. It is probably fair to say that the meeting found that TMS/rTMS is a relatively safe procedure, promising great clinical benefits. Aas long as sensible guidelines are observed, research should continue to be encouraged.

Stimulus parameters which appear important in determining response include frequency, intensity, train length, inter-train interval, total number of stimuli and the pulse waveform. Because of the need to understand the physiological and clinical effects of the full range of frequencies, a consortium met and discussed how wasteful duplication could be avoided. This had similarities to the human genome project in which, by friendly agreement, different laboratories undertook to examine different parts of the genome. In Bethesda, different groups agreed to examine the effects of different frequencies. This was not a compulsory matter and groups are, of course, free to do as they wish. Should readers wish to know more on this particular issue they could perhaps communicate with Dr Wassermann.

There was unanimous agreement that the meeting had been a great success. It could be said that this was like the first round of a boxing match, in which the participants size each other up - although the tone was one of cooperative goodwill rather than the fierce competition which, surprisingly, is sometimes more vigorous between researchers than boxers! The links made between participants and attendees were as important as the officially scheduled papers.

Everyone thought a further meeting devoted to TMS/rTMS in mid-1997 was a good idea. Dr Thomas Schläpfer of Johns Hopkins will be working in Switzerland next year and agreed to organise such a meeting.

Addendum

Dr Wassermann has based the article in part on the information presented at the conference, and has synthesised a consensus view on safety concerns and best practice recommendations. He has indicated his willingness to discuss the summary with interested researchers or clinicians, and can be contacted via his entry on the contacts page.