Transcranial Magnetic Stimulation (TMS)
Sutter Center for Psychiatry
Transcranial Magnetic Stimulation (TMS) uses short pulses of magnetic fields to stimulate nerve cells in the area of the brain thought to control mood. These pulsed magnetic fields may have a positive effect on the brain's neurotransmitters levels. Treating depression with transcranial magnetic stimulation (TMS), may provide an alternative depression treatment for those who have not benefited from prior antidepressant medication.
In studies of "real life" clinical practice, approximately 60% of patients with treatment resistant depression responded to TMS. In a similar study, medications achieved only a 17% response rate.
Psychiatric Intervention Medical Associates added TMS to our range of Interventional Treatments in 2012, giving us another treatment option for those patients unresponsive or intolerant of medication.
About Transcranial Magnetic Stimulation
Transcranial Magnetic Stimulation (TMS) is a treatment approved by the US Food and Drug Administration (FDA) for patients suffering from depression who have not achieved satisfactory improvement from prior antidepressant treatment.
- Is an outpatient procedure performed in a psychiatrist's office
- Is non-invasive, meaning that it does not involve surgery
- Does not require any anesthesia or sedation; the patient remains awake and alert during the treatment
- Is focal and non-systemic, meaning it does not circulate in the bloodstream like medications
The typical initial treatment course consists of at least 5 treatments per week over a 4-6 week period for an average of 20-30 total treatments. Each treatment session lasts between 20 and 40 minutes.
TMS for Depression
For decades, researchers have sought safe and effective treatments for depression. There is no single depression treatment which has been proven to work for everyone. While depression is often treated with antidepressant medications and psychotherapy, many patients have treatment-resistant depression that does not respond to these first and second line treatments.
For these patients, alternative treatments are available. These depression therapies have been shown to work in people who do not receive benefit from medications or cannot tolerate the side effects caused by them. One alternative therapy for the treatment of depression is transcranial magnetic stimulation (TMS). TMS has been approved by the FDA for patients suffering from depression who have not achieved satisfactory improvement from prior antidepressant medications.
How Does TMS Work?
Using an electromagnetic coil, TMS generates highly concentrated magnetic fields which turn on and off very rapidly. These magnetic fields are the same type and strength as those produced by a magnetic resonance imaging (MRI) machine.
The treatment coil is applied to the head above the left prefrontal cortex. This part of the brain is involved with mood regulation, and therefore is the location where the magnetic fields are focused. These magnetic fields do not directly affect the whole brain; they only reach about 2-3 centimeters into the brain directly beneath the treatment coil. As these magnetic fields move into the brain, they produce very small electrical currents. These electrical currents activate cells within the brain which are thought to release neurotransmitters like serotonin, norepinephrine, and dopamine. Since depression is thought to be the result of an imbalance of these chemicals in the brain, TMS can restore that balance and, thus, relieve depression.
Depression is now the leading cause of disability in the world (WHO, 2012), and Transcranial Magnetic Stimulation (TMS) is increasingly recognized as an important treatment option by both clinicians and insurance companies.
As such, we are frequently asked about the relative effectiveness of medications vs. TMS vs. ECT for treatment-resistant depression. While head to head studies of the 3 treatments have not been completed, it is interesting to compare large, multi-site, frequently cited studies of the 3 treatment modalities administered to patients with similar levels of treatment resistance. The graph below shows (in the middle bars), the response and remission rate to TMS treatment for patients who have not responded to, on average, 2.5 adequate trials of medication. As you can see, TMS is not as effective as ECT treatment (bars on the right), but far more effective than yet one more trial of medication would be (bars on the left).
These findings are a useful reminder of the need to regularly assess the severity of depression in our patients, and to be sure that patients with treatment-resistant depression are being treated in a program that can provide the most appropriate treatment modality for them, including TMS , ECT, Ketamine Infusion Therapy or other procedures, when psychotherapy and medication trials have failed.
Clinical trials have demonstrated the safety of TMS in treating patients who have had an inadequate response to prior antidepressant medications. Treatment with TMS caused very few side effects and was generally well tolerated by patients. The most common side effect reported during clinical trials was scalp discomfort-generally mild to moderate and occurring less frequently after the first week of treatment.
Fewer than 5% of patients discontinued treatment with TMS due to adverse events.
Over 10,000 active treatments have been performed across clinical trials demonstrating its safety
No systemic side effects
- No weight gain
- No sexual dysfunction
- No sedation
- No nausea
- No dry mouth
No adverse effects on concentration or memory
No drug interactions
TMS Therapy should not be used in patients with implanted metallic devices or non-removable metallic objects in or around the head. This does not include metallic fillings in teeth.
TMS Therapy should not be used in patients with implants controlled by physiological signals. This includes pacemakers, implantable cardioverter defibrillators (ICDs), and vagus nerve stimulators (VNS).
Typical TMS Treatment
A TMS treatment session is a short outpatient procedure that lasts between 15 and 45 minutes. During treatment, you can relax in the treatment chair. You can also speak with our TMS Clinicians whenever necessary. After the procedure, you can immediately return to your normal routine, including driving.
Your first treatment session
Because your psychiatrist needs to individualize TMS to provide the most effective treatment, your first session could last up to an hour and a half. You will be provided with protective earplugs, as the system emits a tapping sound during operation.
Your psychiatrist will first perform a test to identify your motor threshold. The motor threshold is the amount of magnetic field strength that results in a movement of your right thumb. This test is important because it identifies the magnetic field strength that will be used in your treatment. This field strength is customized for each patient to deliver the correct treatment dose.
After this initial procedure, the TMS physician will determine the place on the head where the TMS treatment will be applied and the magnetic coil will be moved to that location. This will allow you to receive optimal treatment.
The TMS Clinician will then administer TMS over an approximately 15 to 45minute period. In 15 to 30-second intervals, the device will deliver rapid "pulses" of the magnetic fields. These will feel like tapping on your scalp. If a patient finds this tapping uncomfortable, your physician will make adjustments to reduce the discomfort.
After the procedure
Immediately following each treatment session, you may return to your normal daily routine, including driving. During or after treatment you may experience headache or discomfort at the site of stimulation. These are common side effects that often improve as further treatment sessions are administered. If necessary, you can treat this discomfort with an over-the-counter analgesic. If these side effects persist, your psychiatrist can temporarily reduce the strength of the magnetic field pulses being administered in order to make treatment more comfortable.
In clinical trials, most patients who benefited from TMS experienced results by the fourth week of treatment. Some patients may experience results in less time, while others may take longer. You should discuss your depression symptoms with your physician throughout the treatment course. If symptoms persist, you may want to consider other antidepressant options.