Psychiatry: Transcranial Magnetic Stimulation
What is rTMS?
The rTMS stands for repetitive transcranial magnetic stimulation. It is not a completely new technology. It has been used in research, scientific fields, and in the field of neurosurgery for quite a long time.
It is used to treat patients with depression who are not responding to medications alone in an adequate manner.
What is it licensed for?
It is an approved treatment for major depressive disorder. Some of the other experimental indications for rTMS include treatment resistant OCD, hallucinations, and seizure disorders. However, major depressive disorder is currently the most established psychiatric indication. It is also used for mapping the brain during surgical procedures and during research.
Is it suitable for everyone?
Like any other treatment, it is not suitable for everyone, and your physician, with your help, can make that decision. It is not suitable for people with certain type of magnetic materials implanted in their body due to risks with magnetic field. It is not generally suitable for people with seizures.
How is it given?
It is an office based procedure that is administered 5 times a week. Patients can drive themselves to the office, and it is administered by either the treating physician or the appropriately trained TMS technician. At the first visit, provider will establish the parameters of treatment such as the strength of the magnetic field required, width and frequency of the magnetic pulse, and the position of the magnetic coil. After the initial visit, magnetic coils can be placed in the preset position and treatment administered on a daily basis. Each treatment session lasts between 10-30min based on various parameters. Patients can drive home after the procedure. Sessions are generally limited to around 30 minutes and modified based on response.
How does it work?
Magnetic fields induced by coil generate small electric signals in the brain matter underneath the coil. These electrical signals modify the connections between neurons and this in turn improves the mood.
Potential complications and side-effects of TMS
Common but mild side-effects include headaches, discomfort at the site of coil placement, and discomfort due to clicking noise produced by the machine. Rare side-effects may include seizures. It is very uncommon for this to happen and may result in termination of further sessions. Seizure risk from rTMS is similar to antidepressant therapy.
rTMS is a time limited therapy. Your provider will discuss with you regarding longer term plan of medication management as well.
Occasionally some patients are given maintenance sessions where rTMS is continued for much longer than the usual 30+ sessions depending on the individual needs.