What are the contraindications to doing TMS?
The standard two contraindications to doing TMS are metal in the head and history of seizures.
History of seizures
For the history of seizures, the safest thing is not to give them TMS but in some ways, you want to weigh the risks and the benefits – the risks of inducing a seizure on a patient if you do certain stimulations against the risk of having their condition continue. Things can happen from their condition if they don’t improve. So I think you have to think about that.
In some ways, a reasonable approach for some patients with seizures is to do an inhibitory stimulation on the other side, especially since this can reduce seizures. I’m not saying people should stimulate people with seizures and I’m not saying they shouldn’t. But if they do, it would be nice to know where it is coming from or where it originates and it would be nice to do an inhibitory stimulation that quiets the brain down.
There’s another stimulation called vagus nerve stimulation, either the surgical version or the transcutaneous version. That may be something in the future that’s added to TMS to reduce the frequency of headaches and the severity of them and to reduce the tendency for seizures. Vagus nerve stimulation is known to prevent and treat seizures.
Metal in the head
The other contraindication for TMS is thought to be metal in the head. If there is any metal in the path of your magnetic field where you’re treating the person, don’t do TMS, unless your absolutely positive that it’s not a magnetic metal. Dental fillings are not a problem.
There are mixed opinions on pacemakers and depending on the coil you use, the heart is reasonably far away from the magnetic field. The magnetic field varies according to the inverse square of the distance.