May 17, 2016
ATLANTA ― Deep transcranial magnetic stimulation (dTMS), already approved for treatment-resistant depression, is proving beneficial for obsessive compulsive disorder (OCD), adult attention- deficit/hyperactivity disorder (ADHD), and other psychiatric conditions, according to new research.
The success of the technology depends on targeting the most appropriate brain regions, the research suggests.
Results from some of these new studies were presented here at American Psychiatric Association (APA) 2016 Annual Meeting.
A number of psychiatric disorders are associated with abnormal neuronal activity patterns in deep brain regions. Such abnormal activity is the target of TMS.
The noninvasive technology involves applying brief magnetic pulses to the brain. The pulses are administered by passing high currents through an electromagnetic coil placed adjacent to the patient’s scalp. The pulses induce an electric field in the underlying brain tissue.
Conventional TMS was approved in 2008 for the treatment of major depressive disorder, which affects an estimated 15 million Americans a year. But this approach misses the target about 30% of the time, according to Aron Tendler, MD, chief medical officer, Brainsway Ltd.
By contrast, the company’s Deep TMS System has a “wider, broader, and significantly deeper field,” said Dr Tendler.
The Brainsway device, which is encased in a helmet that holds a large magnet, was approved for use in depression in 2013. The company is now investigating different coils and stimulation targets to treat other conditions, including OCD, ADHD, and smoking cessation.
In one study, deep TMS was used in 12 patients who had failed not only drug therapy but also at least one course of electric convulsive therapy, which is considered “the most aggressive treatment for depression,” said Dr Tendler.
Ten of these patients underwent an adequate dTMS treatment trial. When the daily pulse intensity, but not the number of sessions, was increased, depression improved.
“We got them to remit,” said Dr Tendler. “Seven out of those 10 patients had remission from their depression.”
An advantage of this deep TMS approach, he said, is that a physician can treat a suicidal or depressed patient who comes into the office right away; there is no need for laboratory work or x- rays.
In addition, he said, the treatment takes only 20 minutes per session. “The patient sits down, you put a helmet on their head, and you do the stimulation.”
A typical round of treatment consists of 22 to 44 sessions 5 days a week. The treatment, he said, is covered by most insurance plans, typically under certain conditions ― for example, in patients in whom medications have failed medications.
OCD, ADHD, Schizophrenia
The device also appears promising for OCD. It is believed that this condition involves dysfunctional cortico-striato-thalamo-cortical circuits.
Whereas conventional TMS coils cannot directly target these circuits, dTMS apparently can.
To test this, researchers first provoked 40 patients to “obsess” and then treated them with dTMS (high [20-Hz] or low [1-Hz)] frequency) or a sham coil 5 days a week for 5 weeks in a double- blind, controlled setting. They targeted the current to the medial prefrontal cortex and the anterior cingulate cortex beneath.
For the group that received high-frequency active treatment, scores on the Yale-Brown Obsessive Compulsive Scale improved significantly in comparison with the groups that received low-frequency treatment and placebo (P = .0243)
A multicenter, randomized controlled trial is now underway and has enrolled about 60 of the target 96 patients with OCD, said Dr Tendler. The study will again compare active stimulation to sham treatment. Results are expected later this year.
Dr Tendler also presented promising results of another randomized, sham-controlled study of the device ― this time in 42 adult patients with ADHD. Here, the target of the stimulation was the right prefrontal cortex.
Although stimulants are an effective treatment for ADHD, some patients cannot tolerate them, said Dr Tendler. “Taking stimulants for a long time is not necessarily the best thing for everybody,” he said.
Another area of research is schizophrenia. The investigators conducted a study of the use of stimulation of the prefrontal cortex in four patients with schizoaffective disorder and one with schizophrenia, all of whom had comorbid depression. In all five patients, depression improved ― two patients responded, and three patients went into remission.
“This is probably the only treatment that we know of that works for the negative symptoms of schizophrenia,” said Dr Tendler.
He believes that when it comes to dTMS, location of the stimulation is the key to success. Sometimes it takes trial and error or attempts at several different target sites to achieve success.
Yet another study showed that the medial prefrontal, medial orbitofrontal, and anterior cingulate cortices could be alternative targets of stimulation for the treatment of severe depression. Combining treatment targets in patients whose conditions fail to respond might improve the remission rate, said Dr Tendler.
The Brainsway device costs about $200,000 but can be leased for $72,000 per year. The cost includes maintenance.
It is not difficult to learn to use the technology, although there is still a risk, albeit slim, of seizures, said Dr Tendler.
Commenting on the findings for Medscape Medical News, David Feifel, MD, PhD, professor, Departments of Psychiatry and Neurosciences, University of California, San Diego, and founding director, UCSD Center for Advanced Treatment of Mood and Anxiety Disorders, estimates that in the past 2 years, he has used the Brainsway device on more than 100 patients with treatment-resistant major depressive disorder.
Although deep TMS is currently approved only for major depression, the preliminary results of studies of the device in OCD, PTSD, nicotine addiction, and for the negative symptoms of schizophrenia are “exciting” and “positive,” said Dr Feifel.
Dr Tendler is an employee of Brainsway. Dr Feifel is participating in Brainsway multisite studies in OCD, PTSD, and smoking cessation, for which he receives research funding.
American Psychiatric Association (APA) 2016 Annual Meeting: Abstract 131, presented May 16, 2015.