What is the history of Transcranial Magnetic Stimulation?
Since the 1980s, Transcranial Magnetic Stimulation (TMS) has been used to study the nerve fibers that carry information about movements from the brain to the spinal cord and on to the muscles. In the late 1990s, physicians began to explore the therapeutic potential of TMS for the treatment of a variety of diseases, with depression being the most thoroughly studied to date. Since then, researchers have started looking in to using TMS for the successful treatment of many new indications such as OCD, bipolar depression, addiction, and stroke rehabilitation (just to name a few).
Why does rTMS work?
Through a treatment coil, the TMS Therapy system generates highly concentrated, magnetic fields which are rapidly switched on and off. These magnetic fields do not directly affect the whole brain; they only reach a few centimeters into the brain, directly beneath the treatment coil. TMS or transcranial magnetic stimulation refers to a medical treatment which is delivered by a device that generates changing magnetic fields. There are many devices which can be used by clinicians. At present, in general, the devices are positioned over the area of the brain which has been targeted by the clinician. For depression, this area is the prefrontal cortex of the brain. These magnetic fields can create electrical activity in the nerve cells. At the present time, the mechanism of action is not known, but could be related to this direct electric activity or indirect neurotransmitter effects in the brain. Regardless of the mechanism, it is well accepted by researchers and clinicians, that the magnetic stimulation effects not only the targeted area, the prefrontal cortex, but also the connected areas of the brain, the cingulate, amygdala, hypothalamus, and thalamus.
When is rTMS used?
Antidepressant medications and psychotherapy are the first line of treatment for major depression. These treatments, however, do not work for all patients. In these instances, rTMS (transcranial magnetic stimulation) might be used as an alternative treatment, or to augment antidepressant medications or psychotherapy. Patients who have failed to achieve an adequate response from antidepressants, or who are unable to tolerate medications, should consider rTMS therapy.
What Happens During an rTMS Procedure?
rTMS uses magnetic pulses, so before beginning a treatment, patients are asked to remove any magnetic-sensitive objects (such as jewelry or glasses). Patients are required to wear earplugs during treatment for their comfort and hearing protection, as rTMS produces a loud clicking sound with each pulse, much like an MRI machine. Patients are seated during each session of rTMS.
During the first rTMS session, several measurements are made to ensure that the TMS coil will be properly positioned over the patient’s head. Once this is don, the TMS coil is suspended over the patient’s scalp. The TMS treater then measures the patient’s motor threshold, by administering several brief pulses. The motor threshold is the minimum amount of power necessary to make the patients thumb twitch, and varies from individual to individual. Measuring the motor threshold helps the treater personalize the treatment settings and determine the amount of energy required to stimulate brain cells.
Once the motor threshold is determined, the coil is the brought forward so that it rests above the front region of the patient’s brain. Treatment is then commenced. During the treatment, patients will hear a series of clicking sounds and will feel a tapping sensation under the treatment coil.
Motor threshold is not checked at every treatment but may be reassessed if there is concern it may have changed, for example, because of a change in medication.
Who Administers rTMS?
rTMS is always prescribed by a TMS treater. At TMS Therapy, all TMS treaters are specifically TMS credentialed by a qualified trainer. The initial motor threshold is always administered by a physician and a TMS treater. The treatment itself is administered by an experienced TMS treater under the supervision of a TMS physician or by the TMS physician. The TMS treater or physician will always be present to monitor the patient during the treatment. The patient can stop at any time just by asking the treater or physician present.
How Long is an rTMS Procedure?
rTMS therapy involves a series of treatment sessions. Treatment sessions take just under 19 minutes in the chair, se we ask patients to plan to be at the office for about 30 minutes. Patients receive TMS 5 days a week, for 6 weeks, amounting to 36 sessions.
Do I need to be Hospitalized for a Course of rTMS?
Unlike ECT, rTMS does not require any kind of sedation or general anesthesia, so patients are fully awake and aware during the treatment. There is no “recovery time” either, so patients can drive home afterwards and return to their usual activities.
What are the side effects of rTMS?
rTMS is well-tolerated and associated with few side-effects and only a minuscule amount of patients discontinue treatment because of these side-effects. The most common one, which is reported in about Hal of patients treated with rTMS, is headaches. These are mild and generally diminish over the course of treatment. Over- the-counter pain medication can be used to treat these headaches.
About one third of patients may experience uncomfortable scalp sensations or facial twitching with rTMS pulses. These too tend to diminish over the course of treatment although adjustments can be made immediately in coil positioning and stimulation settings to reduce discomfort.
The rTMS machine produces a loud noise and because of this earplugs are given to the patient to use during the treatment. However, some patients may still complain of hearing problems immediately following treatment. No evidence suggests these effects are permanent if earplugs are worn during the treatment.
rTMS has not been associated with many of the side-effects caused by anti-depressant medications, such as gastro-intestinal upset, dry mouth, sexual dysfunction, weight gain or sedation.
The most serious risk of rTMS is seizures. However, the risk of a seizure is exceedingly low. At TMS Therapy of Louisville and affiliates, we follow up-to-date safety guidelines that are designed to minimize the risk of seizures. While rTMS is a safe procedure, it is important to point out that because it is a new treatment, there may be unforeseeable risks that are not currently recognized.
Who Cannot Get rTMS Therapy?
Patients with any type of non-removable metal in their heads (with the exception of braces or dental fillings), should not receive rTMS. Failure to follow this rule could cause the metal object to heat up, move, or malfunction, and result in serious injury or death. The following is a list of metal implants that can prevent a patient from receiving rTMS:
- Aneurysm clips or coils
- Stents in the neck or brain
- Deep brain stimulators
- Electrodes to monitor brain activity
- Metallic implants in your ears and/or eyes
- Shrapnel or bullet fragments in or near the head
- Facial tattoos with metallic or magnetic sensitive ink
- Other metal devices or objects implanted in or near the head
Does TMS Work?
One study found at 12 months, 68% of patients achieved symptomatic improvement, and 45% reported complete remission. Maintenance of benefit was observed under a pragmatic regimen of continuation antidepressant medication and access to TMS reintroduction for symptom recurrence.
The durability of TMS Therapy demonstrated by this robust, real-world study is remarkable, as it’s not typical to see long-term benefit in patients who have treatment-resistant forms of depression,” study investigator Philip Janicak, MD, professor of psychiatry, Rush University Medical College, and medical director of the Rush Psychiatric Clinical Research Center, in Chicago, said in a statement.