The National Institute of Mental Health is currently recruiting participants for a clinical study to see if using functional magnetic resonance imaging (fMRI) to guide repetitive transcranial magnetic stimulation (rTMS) helps locate the best area for treatment and to explore [..]
Electroconvulsive Therapy (ECT) and Transcranial Magnetic Stimulation (TMS) are both cranial therapies used in the treatment of mental illness or mood disorders. ECT uses an electric current and is usually administered in a hospital setting and associated with various side effects, some of which may be serious such as memory loss. TMS, by contrast, is a non-invasive therapy and is generally administered in a doctor’s office or out-patient setting and commonly has no side effects. The following is a detailed outline of the differences between ECT and TMS.
The Definition of Each
ECT: ECT is an acronym for electroconvulsive therapy (sometimes referred to as electroshock therapy or just shock therapy). ECT therapy involves directing an electric current into the patient’s brain through electrodes attached to the scalp to intentionally cause a series of “generalized seizures”.
TMS: TMS is an acronym for transcranial magnetic stimulation (sometimes referred to as repetitive transcranial stimulation or rTMS). TMS therapy is a non-invasive method of stimulating neuronal activity in specific regions of a patient’s brain using induced electrical currents caused by high intensity pulsed magnetic beams.
ECT: For centuries prior to the 1900s, medical science had observed that many patients suffering from mental disorders improved where the patients experienced convulsions due to unrelated illnesses. In 1917 doctors in Europe began experimenting with malaria fever induced seizures to treat mental disorders. This was followed by drug (e.g. insulin) induced seizure experimentation and in 1937 doctors in Italy began treating patients using electric current induced seizures using a process that has become known as electroconvulsive therapy or ECT.
For approximately 30+ years after electroconvulsive therapy was developed, ECT was widely popular as a method of treating a wide variety of mental illnesses including depression and anxiety related disorders. However, by the mid-1970s the development of newer antidepressant and anxiolytic drugs and the stigma surrounding ECT caused use of ECT to decline significantly.
In recent years ECT use has increased for severe cases of mental illness as methods of delivery of the electric current have improved and better anesthesia management has been developed. This is particularly the case when drug therapy has proven unsuccessful or such therapy is deemed too slow to meet the immediate medical needs of a patient. It is estimated that approximately 100,000 people receive ECT therapy in the United States each year.
TMS: The principles underlying electromagnetic induction were discovered by Michael Faraday in 1831. In the early 1900s a number of attempts were made to use it to stimulate brain activity. Technological deficiencies caused these attempts to be unsuccessful. However, by 1985 a group in the United Kingdom was able to demonstrate stimulation of the human brain using electromagnetic induction—i.e. TMS. Magnetic stimulation uses a magnetic field pulse to induce electric currents in the brain. Thus, “magnetic stimulation” is really “electrical stimulation” which is created through magnetic pulses. Interest in TMS developed rapidly after it was first demonstrated as both a diagnostic as well as a therapeutic tool. In 2009 the Federal Drug Administration approved commercialization of the first device for clinical TMS therapy. Since then thousands of patients have been successfully treated for depression, anxiety, PTSD, OCD and other mental disorders using TMS therapy.
What is Involved
ECT: ECT today is generally administered in a hospital setting. Because the treatment is designed to cause a series of generalized seizures, patients are given muscle relaxants (to prevent damage to muscles and bones during seizures) and a general anesthetic and so are not conscious during the therapy. Typically electrodes are placed on the right side of the head and on the top of the cranium (a “unilateral” treatment). If this unilateral approach is not effective, electrodes may be placed on opposite sides of the head near the temples (a “bilateral” treatment). The different placement of electrodes has been associated with differing degrees of side effects including memory loss (see discussion of side effects and memory loss below).
A typical course of ECT therapy consists of between 6 and 15 initial sessions (referred to herein as the “acute” treatments). These are usually spaced about a day apart (e.g. Monday, Wednesday, Friday). Improvement in symptoms is normally not observed until 6 or more sessions have been completed. Many patients (estimated to be in excess of 70%) obtain significant near term relief of symptoms through ECT therapy. However, for many patients, the benefits of ECT “wear off” after several months. It is estimated that approximately 50% of patients receiving ECT therapy relapse after 6 to 12 months. For this reason, doctors often recommend a course of maintenance ECT after completion of the acute treatment phase. A common regimen of maintenance ECT would be: once per week for a month; followed by once every two weeks for two months; then once every three weeks for two months; and, finally, once a month for two to four months. Thus, patients receiving ECT therapy including a maintenance program after the acute phase would receive between 19—30 ECT treatments.
Given the relapse rate for ECT patients, ECT is not considered a cure for the illnesses being treated and patients are expected to continue with drug therapy. In fact, the acute phase of ECT is often commenced with patients exhibiting severe symptoms as a way to treat the illness until a drug regimen has had time (normally 3 – 4 weeks) to take effect.
TMS: TMS therapy is generally administered in a doctor’s office or out patient setting. Unlike ECT, TMS does not cause a series of seizures. Therefore, there is no need to anesthetize patients or give them muscle relaxants. TMS patients are fully awake during the therapy and are able to converse, listen to music or watch video throughout the procedure.
The first TMS therapy session begins with the patient being placed in a chair similar to a dentist’s chair and made comfortable. The medical doctor then performs what is known as a “motor threshold determination” which consists of determining (1) where to place the magnetic coil and (2) the intensity of the magnetic pulse. The physician will also determine the number of pulses that the patient is to receive with each session. A typical session of TMS lasts from +/- 37 minutes for a unilateral treatment up to +/- 70 minutes for a bilateral treatment.
A typical course of TMS therapy for depression consists of approximately 30 to 36 sessions delivered 5 days per week for 6 – 7 weeks. Improvement in symptoms is normally not observed until 10 to 15 sessions have been completed. In clinical studies submitted to the FDA, a full course of TMS therapy for depression was found to have resulted in over 60% of patients achieving a “significant response” (which was defined as a greater than 50% reduction in pre-treatment symptoms) and over 41% achieving complete remission. In additional studies submitted to the FDA, at 12 months following the end of treatment 68% of patients reported “significant response” while 45% reported complete remission.
ECT: Yes, there can be a number of side effects including headaches, muscle aches, nausea and confusion following therapy. Because of the possible confusion and other side effects noted above, patients usually are observed for a period of time at the hospital following treatment before being released.
TMS: Some patients experience mild scalp discomfort in the area where the magnetic coil is placed against the scalp. This usually is short-lived and can be addressed by a temporary reduction in the intensity of the magnetic pulse until the patient adjusts to the procedure.
ECT: ECT therapy has been positively connected with two different kinds of memory loss. The first is “short term” memory loss in which the patient may not be able to remember things that occurred in the recent past such as what he or she had for breakfast that morning. This inability to remember “new” information is generally thought to dissipate over a few weeks or a few months. The second type of memory loss is “long term” or “longer term” meaning that the events that cannot be recalled occurred in the more distant past—e.g. more than two weeks earlier. This second type of memory loss is considered more likely as a result of ECT and may be permanent.
TMS: No memory loss has ever been reported from TMS therapy. To the contrary, some evidence exists which suggests that TMS therapy may actually act as a cognitive enhancement vehicle.
ECT: ECT is considered by the medical profession to be a relatively safe procedure notwithstanding the side effects discussed above. However, any procedure that, like ECT, involves anesthesia carries risks. The risk of respiratory or cardiac arrest from anesthesia resulting in death is estimated at less than 1 in 10,000.
TMS: TMS is considered by the medical profession to be a very safe procedure. It does not have any serious side effects and does not require anesthesia as ECT does and, therefore, does not carry the same risk of respiratory or cardiac arrest.