+ What is repetitive transcranial magnetic stimulation (rTMS)?

rTMS is a Health Canada-approved treatment for major depression and is also being studied as a treatment for other psychiatric and neurological disorders. Unlike medications or psychotherapy, rTMS works by directly stimulating areas of the brain that are underactive or overactive, gradually returning them to healthy patterns of activity. To stimulate the brain, rTMS uses powerful, focused magnetic field pulses that are applied using a magnetic coil placed against the scalp, over the target brain region. When applied repeatedly, these pulses can strengthen or weaken the connections between neurons, known as synapses. The long-lasting changes in neural connections can achieve lasting changes in brain activity, reversing the abnormal patterns associated with depression. More information about rTMS and its use in treating depression is available in the other sections of the website.


+ What happens during a course of rTMS treatment?

If you decide to undergo rTMS, the first step is to schedule an MRI for rTMS guidance. Our MRIs are done on Wednesday and Thursday evenings at the Toronto Western Hospital. On the Friday after the MRI, you will come to the rTMS clinic for a calibration session, in which we locate the target region, determine the correct strength of stimulation for treatments, and have you complete a series of standardized questionnaires to measure the severity of your symptoms. The course of treatment begins the following Monday. A full course of treatment involves 20-30 sessions, given on weekdays from Monday to Friday. With once-daily treatment, the course will last 4-6 weeks. If treatments are given several times per day, the course is shortened to as little as 5 days. A treatment session usually lasts just over 45 minutes. However, with some types of rTMS, the session can be completed in 10-15 minutes.


+ Are there any activity restrictions during rTMS treatment?

No. Most people do not require any recovery period after completing a session of rTMS, and may continue their daily activities as usual. There are no restrictions on driving before or after rTMS treatments. You do not need to bring anyone with you to your rTMS sessions, although some people prefer to have a spouse, relative, or friend accompany them for the first few treatments. If you are working, you do not need to stop working to undergo rTMS so long as your schedule can accommodate the treatment visits. Patients who are working professionals sometimes schedule rTMS appointments during the lunch hour, and return to work for the afternoon. The rTMS Clinic operates from 9am to 5pm weekdays, and appointments are usually scheduled at the same time each day within these hours. However, in special circumstances, exceptions can be arranged and treatments can be scheduled in the early morning or evening, just outside normal working hours.


+ What are the potential benefits of rTMS in depression?

Dozens of studies since the early 1990s have shown rTMS to be an effective treatment for major depression, even in cases where medications have failed. In the most recent generation of rTMS trials, about 50-60% of people achieve response (that is, at least a 50% reduction in symptoms on standard scales), and about 30-40% of people achieve remission from depression. rTMS is not yet considered to be as powerful as more invasive brain stimulation treatments such as electroconvulsive therapy (ECT) or implantable deep brain stimulation (DBS) electrodes. However, it has the advantage of having no known long-term side effects and in most cases no short-term side effects aside from some discomfort during the stimulation itself. What is repetitive transcranial magnetic stimulation?


+ What are the potential benefits of rTMS in other disorders?

Over the last 20 years, rTMS has been studied as a treatment for a wide variety of neurological and psychiatric disorders, including depression and bipolar disorder, schizophrenia, obsessive-compulsive disorder, panic disorder, post-traumatic stress disorder, specific phobias, substance abuse and addiction, eating disorders such as bulimia nervosa and anorexia nervosa, and neurological conditions such as Tourette syndrome, movement disorders, dementia and mild cognitive impairment. Aside from depression, the use of rTMS in treating these disorders remains experimental. For some of these conditions, rTMS does appear promising, with some patients achieving significant improvements in symptoms. The UHN rTMS Clinic has ongoing studies to explore the benefits of rTMS in eating disorders, chronic pain, and in mothers with post-partum depression. If you are interested in considering rTMS for a condition other than depression, your physician can request an assessment for you.


+ What are the potential risks of rTMS?

For the majority of people, there are no serious risks to rTMS. The most common side effect with rTMS is discomfort during the stimulation session itself. In addition to stimulating the brain, the magnetic pulses of rTMS can also stimulate the nerves in the areas of scalp, forehead, or face near the stimulation coil. This creates an unpleasant sensation similar to static electricity. Although this improves considerably over the course of treatment, the first few sessions can be quite uncomfortable for some people. Over the counter pain remedies such as ibuprofen (Advil) or acetaminophen (Tylenol) can be helpful for the first few sessions. A minority of people report fatigue or a mild headache in the hours after the treatment session is over. A small number of people (3-5%) may feel faint, or may briefly faint, during the first one or two sessions. Much rarer risks include the emergence of hypomania (a high-energy, hyperactive state similar to the opposite of depression) or thoughts of self-harm (although not actual acts of self-harm) in less than 1% of cases. The most serious known risk with rTMS is the induction of a seizure during brain stimulation, reported in approximately 1 in 10 000 cases. For comparison, the risk of seizure on most antidepressant medications is about 1-5 in 1 000 cases. Despite the risk of a seizure during actual stimulation, there is no evidence that rTMS can cause the more general condition of epilepsy, in which seizures occur spontaneously outside of stimulation sessions. In fact, inhibitory forms of rTMS have been studied as a treatment for epilepsy.


+ What are the advantages of rTMS over other treatments?

rTMS has the advantage of few side effects, other than transient pain at the stimulation site, in the majority of people. Unlike ECT, rTMS has no known side effects on memory, attention, concentration, or intellectual function. rTMS does not require anaesthesia or sedation, so people undergoing treatment can usually continue with their daily activities immediately after treatment. For those who have not responded to medication, or who have not been able to tolerate the side effects of medication, and for those who are uncomfortable with undergoing ECT, rTMS can be an attractive option.The main disadvantage of rTMS is that it requires daily hospital visits for treatment. For people who live far from the clinic, or are working full-time, or have full-time responsibilities as a parent or caregiver, it can be quite inconvenient to come to the hospital every weekday for several weeks. For this reason, most people choose to try medications first, turning to rTMS if the medications are ineffective or hard to tolerate.rTMS is not a permanent treatment, and relapse after treatment is possible. Typically, the effects of rTMS will last for at least 6 months in 90% of cases, and generally last for 6-12 months. We strongly encourage patients to use the time after treatment to pursue a course of psychotherapy and address major life stressors to reduce the risk of relapse. However, if relapse does occur, repeat rTMS is possible. Those who respond to rTMS once will usually respond to rTMS again in the future if it is needed.


+ What happens after the rTMS treatment is complete?

We offer follow-up appointments at 2, 6, 12, and 26 weeks after treatment. These follow-up appointments are an opportunity to evaluate symptoms, review progress, arrange follow-up medication or psychotherapy for responders, and arrange other options for nonresponders.We strongly recommend that patients who complete rTMS enroll in a course of therapy to help prevent relapse. Usually, for patients with depression, we recommend enrollment in Mindfulness-Based Cognitive Therapy or Mindfulness-Based Stress Reduction, although other therapies may also be helpful.Unfortunately, due to the volume of patients undergoing treatment, we are not able to offer long-term follow-up after rTMS is complete. We are also not able to offer management of medications during or after treatment. In the event of relapse after successful treatment, we do offer the possibility of booster or maintenance rTMS treatments. These additional treatments are usually effective if rTMS has been successful in the past.


+ How do I know if rTMS will work for my depression?

In our experience, the response to treatment tends to be all-or-none: some people improve considerably, while others show essentially no response at all. In general, about 55% of the people who undergo rTMS at the UHN Clinic show a response to treatment. Response rates are similar for both unipolar and bipolar depression. Response is more likely in individuals with an on-and-off course of depression and definite previous periods of normal mood. Response is less likely in people who have had chronic lifelong depression throughout adolescence and adulthood. Response is quite unlikely in people who have previously tried ECT or rTMS with no benefit. Response is less likely in individuals who have active problems with alcohol or other substances. Response is also less likely in individuals who have had lifelong difficulties in social abilities such as forming and keeping friendships, or maintaining good relationships with co-workers. If you have these sorts of difficulties, it may be worth undergoing therapy to strengthen core social and emotional coping skills before antidepressant treatments such as medication or rTMS will help.Our research team has recently developed a technique for using a special type of MRI, called resting state fMRI, to tell apart likely responders and nonresponders before they actually start treatment. This technique may turn out to be quite reliable — in preliminary testing in about 25 people, it achieved about 92% accuracy overall. However, at the moment, this test remains experimental and should not be relied upon unless it proves reliable in a larger group of people. If it does prove to be dependable, this test may become available for routine use in the Clinic by late 2013.


+ What are the costs associated with rTMS?

rTMS is not currently a funded procedure under OHIP. The UHN MRI-Guided rTMS Clinic has a number of studies underway at any given time, and research funds are available to cover the full cost of treatment for participants in these studies. The majority of people who are good candidates for rTMS can be offered participation in one of the studies currently underway. For those people who prefer not to participate in a study, there is the option to pay for the treatment privately or through an insurer.


+ Where else can I obtain rTMS treatment aside from the UHN rTMS Clinic?

Several privately-operated rTMS clinics are also available in Toronto and other major Canadian cities and can be identified through a straightforward Web search for “rTMS in Canada”. Privately-funded rTMS treatment can also be obtained at over 500 sites in the USA, including nearby Buffalo, Detroit, and Cleveland. Several nearby research-based rTMS clinics are also accepting patients for studies, including our colleagues at the Centre for Addiction and Mental Health, at McMaster University in Hamilton, and at Queen’s University in Kingston.


+ How can I get an appointment to discuss having rTMS treatment at UHN?

A course of rTMS treatment at the UHN Clinic begins with a referral from your family doctor or psychiatrist, which can be submitted on paper or electronically via the website. Once this is received, we will contact you for an initial assessment, usually within 2 weeks. At the assessment, we will review the history of the illness, previous treatments you have tried, and screen for medical conditions that might affect your ability to undergo rTMS safely. If rTMS appears to be a suitable and safe treatment in your case, we will discuss potential options for treatment, review potential risks and benefits, and answer any questions you may have. You can then make an informed decision about whether you wish to proceed with a course of treatment.


+ Whom should I contact if I have other questions about rTMS?

For more information please contact the clinic at (416) 603-5667 or rtms.clinic@uhn.ca.