TMS (or transcranial magnetic stimulation) is a non-invasive method of cortical stimulation, in which magnetic pulses are applied to the head using a specialized wire coil (1). It is not
a new technique, with the initial experiments in humans being conducted in the 1980's.
When should it be used?
Repetitive TMS (rTMS) is FDA-approved for the treatment of patients with major depressive disorder who have not had a satisfactory response to at least one adequate trial of an antidepressant (
1). In the US, the FDA regulates the approval and sale of devices that administer TMS, and has provided guidance for
manufacturers (
2). Repetitive TMS is also approved in several other countries. TMS may be underutlized as a treatment
in current practice settings (
3).
Does it work?
There is extensive evidence (see Table 1 in Perera et al. 2016)
from randomized controlled clinical trials, as well as from naturalistic studies, indicating that repetitive TMS is an effective treatment for major depressive disorder.
Does TMS help improve quality of life and function?
Yes, there is evidence, based on several outcome measures, that rTMS helps improve patient reported quality of life and function (1,
2).
How does it work?
While not definitively established, altered synaptic plasticity, metabolism, and blood flow in key areas of the brain are believed to underlie the mechanism of action of TMS. So called 'neurotrophic' effects, effects on glial cells, and even
effects on the genetic apparatus of cells, may also play a role (
1,
2,
3).
Is it safe and well-tolerated?
TMS is generally safe and well-tolerated (
1,
2). Discontinuation rates in trials have been 5% or less. The most common side-effects are scalp pain, skin discomfort, eye pain, toothache, muscle twitches, and
facial pain.Serious side-effects are uncommon. There is a small incident of inducing seizures (estimated to about 1 in 30,000 treatment sessions). Seizures have generally been self-limited and non-recurrent. Vasovagal syncope has also occurred.
Is rTMS cost-effective?
Yes; in fact, TMS has been shown to be potentially more cost-effective than antidepressant medications (
1,
2).
What about other brain stimulation therapies?
Besides TMS, other forms of brain stimulation are available, but they are generally more invasive or have been less well-studied (
1,
2).
Besides MDD, does TMS work for any other disorders?
While not FDA approved for treatment of conditions other than MDD, evidence is accumulating for potential efficacy in other CNS disorders including PTSD, schizophrenia, substance use, ADHD, OCD, epilepsy, stroke rehabilitation, movement disorders, chronic
pain, and tinnitus (
1,
2,
3,
4). Neuronetics continues to conduct clinical research in new areas (5).