Treatment of Depression with repetitive Transcranial Magnetic Stimulation


Depression is one of the most important problems of modern societies. According to the World Health Organization the number of new patients suffering from depression in Europe each year reaches 7% of the general population, and if anxiety disorders are taken into account, the number increases to 27% . According to published studies the number of patients suffering from refractory depression, ie who have not improved adequately after having already tried two different antidepressants, is approximately 2% of the general population. Extrapolating these rates to the population of Greece, 11.280.000 according to the 2011 census, every year 789.000 new patients suffer from depression, 225.000 new patients from refractory depression and 3.045.000 new patients from anxiety disorders.

Until now the main alternative treatment option for refractory depression was electoconvulsive therapy (ECT). Although this is an effective and relatively safe method, electroconvulsive therapy usually requires hospitalization in a psychiatric ward and requires 6-12 sessions, in each of which the patient receives general anesthesia. Main side effects are retrograde amnesia, ie amnesia of the events up to the time of treatment. Impaired attention and concentration, confusion, nausea, headache and vomiting may also occur. It should also be noted that general anesthesia is associated to a risk of death of 0.01%.

These problems are overcome by repetitive Transcranial Magnetic Stimulation, or rTMS, a state-of-the-art method of treatment for resistant depression that has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA).

 

We describe the treatment of depression with rTMS in this video animation.

 Link to YouTube Video

 

Where is it offered?

In a private practice or outpatient unit. There is no need for hospitalization.

How is it done?

During treatment the patient is lying comfortably on a bed. He/she is awake, as there is no anesthesia involved. An electromagnetic coil is placed in contact with the skull at a point chosen by the doctor during the first session, as shown in the figure below. The coil remains in the same place throughout the treatment session.

rTMS Treatment Session

 

The treatment consists of a set of low-intensity electromagnetic pulses delivered at a specific frequency, which are generated by the coil and activate appropriate brain centers, in order to suppress negative feelings and bad moods, and to enhance positive emotions.

How long does it last?

The first session, during which the doctor defines the parameters of the treatment, lasts approximately one hour. Each subsequent session lasts about half an hour.

Sessions are held daily on weekdays. It usually takes 15 to 30 sessions to achieve the desired clinical improvement, thus the total duration of treatment is three to six weeks.

Is it painful?

Each electromagnetic pulse feels like a very light and brief electric discharge, which is felt on the scalp. After the first few pulses, the patient gets used to the process and feels comfortable.

Is it effective?

According to the most recent meta-analyses of patients with refractory depression who were already under antidepressant treatment without satisfactory results, and who received additional treatment with rTMS, 35-40% achieved complete remission. Furthermore, the therapeutic effect of rTMS has a duration simillar to that of other interventions, such as electroconvulsive therapy, as about 60% of the patients who achieved remission initially, continued to be in remission three months after the end of the rTMS sessions.

The size of the therapeutic effect of rTMS is comparable to or greater than that of antidepressants, while the combination of the two leads to faster and more effective treatment of an acute depressive episode.

Of particular importance is the comparison of rTMS with ECT, as both methods are based on similar physical principles (ie the use of electrical impulses for changing the functionality of the cerebral cortex), while the latter is widely regarded as the most effective means of treating resistant depression. Recent studies showed that the likelihood of improvement with rTMS is 50% while with ECT 65%, and the probability of complete remission is 34% and 53% respectively. It should however be noted that the greater efficacy of ECT is seen in a specific subgroup of depressed patients, those with psychotic symptoms, whereas in patients without psychotic symptoms the efficacy of both methods is similar.

The similar efficacy of rTMS with ECT in patients without psychotic symptoms, combined with the best profile and significantly greater comfort of the patients during sessions, make rTMS a great choice for the treatment of refractory depression.

Are there side effects?

In most patients there are no side effects. When they occur, they are mild and transient: headache (which responds well to simple painkillers) and transient ringing in the ears (because of the sound created by the coil). Ear plugs help avoid the ringing, however in our experience, most patients do not need them.

A very rare possible side effect is the occurence of an epileptic seizure. The probability that a seizure occurs is very low (<0.01%) and if it occurs it is isolated, i.e. one seizure only occurs during the treatment and will not be repeated. This probability is lower than the incidence of epilepsy in the general population (0.07-0.09%). To date rTMS has never caused permanent epilepsy, according to the internationall experience. It also should be noted that the seizures occurred in initial clinical studies, where older treatment protocols were used. Newer protocols have, on the contrary, been shown to be protective against epilepsy.

Are there other applications of rTMS?

At this stage rTMS has been approved by the U.S. Food and Drug Administration and the European Medicines Agency for the treatment of refractory depression. However, positive results have been obtained in investigational clinical trials in several other neurological and psychiatric disorders, including the following:

  • Auditory hallucinations that do not go away with medication (in patients with psychotic disorders / schizophrenia)
  • Tinnitus (ringing in the ears)
  • Epilepsy
  • Obsessive-Compulsive Disorder (OCD)

 

 

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