What is transcranial magnetic stimulation (TMS)?
Transcranial magnetic stimulation, or TMS, is a treatment for people with severe depression whose illness has not been helped by at least one antidepressant medication. It is a type of brain stimulation therapy. TMS elicits magnetic energy, which turns into electrical current underneath the patient’s skull, to help regulate the patient’s emotions.
TMS is an adjunct treatment that works along with medication and is non-invasive (does not require surgery).
What is depression?
Depression is a common and serious medical illness. One aspect of depression is a lack of activity in the prefrontal cortex of the brain, or the area right above the eyes, that helps control emotions. It affects how the patient feels, thinks and acts.
Symptoms of depression may include:
- Feeling sad
- Loss of interest or pleasure in activities once enjoyed
- Changes in appetite — weight loss or gain without dieting
- Lack of energy or feeling tired
- Trouble sleeping or sleeping too much
- Thoughts of death or suicide
If these symptoms last at least two weeks or longer, the patient should see a health professional for diagnosis of possible depression. The illness can be treated.
What other conditions can transcranial magnetic stimulation (TMS) be used to treat?
TMS has shown great promise treating the depressed patient, but is also being studied for possible treatment of other conditions, such as vascular depression following a stroke. Also, researchers are looking at TMS as a possible treatment for schizophrenia, attention deficit-hyperactivity disorder (ADHD) and post-traumatic stress disorder (PTSD).
What can the patient expect during the transcranial magnetic stimulation (TMS) procedure?
The procedure is usually performed by a doctor while the patient is awake and seated in a chair. A device with an electromagnetic coil is placed near the patient’s left prefrontal cortex, or the front side of the scalp, an area where a lack of functional and metabolic activity is found in the depressed patient.
The device is held in place for about 40 minutes. A steady electric current is passed through this part of the brain causing neurons, or nerve cells, in the brain to send electrical impulses. These impulses will then trigger a chemical reaction that, over time, will help lift the patient’s mood.
Doctors typically recommend 30 sessions of TMS therapy, usually given five times per week for four to six weeks.
Because this type of pulse generally does not reach further than 2 inches into the brain, the doctor can specifically target the portion of the brain to treat. This precision also lessens the chance for side effects that may occur with other procedures.
What different types of transcranial magnetic stimulation (TMS) treatment are available?
Repetitive transcranial magnetic stimulation (rTMS) uses more intense electric pulses.
- rTMS is used to treat patients with unipolar depression.
- In rTMS an electromagnetic coil is held against the patient’s left side of the scalp while short electromagnetic pulses are administered through the coil. The magnetic and repeating pulses cause small electrical currents that stimulate nerve cells in the targeted region of the brain. Each rTMS session usually lasts 30 to 60 minutes and does not require sedation or anesthesia.
- The strength of these currents is about the same as a magnetic resonance imaging (MRI) scan.
- Research is still being conducted on the best treatment options for rTMS, such as whether the procedure works best as a single treatment or when the procedure is combined with medication and/or psychotherapy.
- Side effects of rTMS, such as headaches, scalp discomfort, or brief lightheadedness, are mild or moderate. Some patients may feel a tingle of the muscles of the scalp, jaw or face during the procedure. Although rare, it is possible that the procedure could cause a seizure.
Deep transcranial magnetic stimulation (dTMS) is a relatively new method of stimulating larger, deeper brain regions.
- The procedure uses specialized coils, called H coils, which reach about 2 inches beneath the surface of the skull and are designed to target different brain areas.
- During a dTMS session, a person wears a cushioned helmet, which generates brief magnetic fields, similar to those in MRI scans. This is an outpatient procedure that does not require anesthesia.
- The procedure takes place daily with 20-minute sessions over four to six weeks. The patient can resume normal activities immediately after the procedure. The dTMS procedure has few side effects and does not result in seizures or memory loss.
Risks / Benefits
What are possible side effects of transcranial magnetic stimulation (TMS) treatment?
Doctors report minimal side effects for the patient being treated with TMS. Some may feel a twitching or vibrating sensation around the face, cheek or scalp, or complain of a headache or muscle soreness. There is a low risk of seizure.
Who would benefit from transcranial magnetic stimulation (TMS)?
Before beginning any treatment for depression, the patient should talk with his or her therapist, doctor, or other mental health treatment provider. Each patient is different and what works for one may not work for another.
TMS is used on the patient who has not responded to medication when treated for depression. Many mental health professionals report promising results from this treatment. However, the procedure is still undergoing research on its effectiveness and long-term results.
Who should not be considered for transcranial magnetic stimulation (TMS)?
The TMS procedure is not recommended for patients who have a history of seizures. Those who have a metal plate in their head, or any other metal in and around their head should not have the procedure done. Braces and fillings will not interfere with the treatment.
Recovery and Outlook
How long after the (TMS) treatment can the patient expect to see results?
Doctors say that the patient often experiences relief from TMS within two to four weeks.
What follow-up is necessary after the transcranial magnetic stimulation (TMS) procedure?
Depending on the patient’s outcome, follow-up sessions may be recommended every few weeks or months to help maintain the positive results.
How does transcranial magnetic stimulation (TMS) differ from electroconvulsive therapy (ECT)?
Both TMS and electroconvulsive therapy (ECT) are used to treat severe depression.
ECT has been used in the United States for more than 70 years and creates a more generalized brain stimulation. It sends a small electrical current that is sent through the brain to trigger a short seizure. The current causes a short seizure within the brain, which produces changes in the brain’s functioning and chemistry. The patient needs anesthesia during the procedure. ECT is usually recommended several times per week over three to four weeks.
The patient may experience confusion and some memory loss after the ECT procedure. Because anesthesia is used, additional risks must be considered, and means longer preparation and recovery time for each session.
The doctor may recommend ECT if a patient has tried multiple medications or therapies that have not worked, or if he or she is suicidal, psychotic or catatonic.
In contrast, TMS is a more recent form of treatment. It is a much more targeted procedure. The patient is awake and alert the entire time. Side effects of TMS are minimal and the patient does not suffer any memory loss.