How Does Transcranial Magnetic Stimulation Work?

Treatment resistant depression is incredibly difficult to control. When patients present with MDD (Major Depressive Disorder), and it does not respond favorably to SNRIs or SSRIs, mental health counseling, and other traditional treatment options, it’s necessary to reassess what’s available. Transcranial Magnetic Stimulation, or TMS for short, is an FDA-cleared treatment regimen for OCD, MDD, and other treatment-resistant mental health conditions.

It is unlike ECT (Electroconvulsive Therapy), where surgical procedures are required. With TMS therapy, patients undergo nonsurgical treatment involving a specialized helmet that transmits magnetic waves into targeted parts of the brain. The goal is to stimulate nerve cells, thereby improving the symptoms of depressive disorders. Typically, Deep TMS (an enhanced and more effective form of TMS treatment than traditional TMS) delivers repetitive pulses into the patient’s brain to alleviate and reconfigure neural function. The electromagnetic coil in the helmet is positioned in close proximity to the scalp, for painless treatment. The magnetic pulses only target specific areas in the brain responsible for mood disorders.

The science shows that there are decreased levels of neural activity in patients with depression. The TMS stimulation positively impacts brain functionality, and this alleviates the symptoms of depression. The first step in the process requires an evaluation to determine the motor threshold. This is the stimulation intensity of the TMS treatment.

The TMS Magnetic Coil

Next, the anatomical target of the magnetic coil must be assessed. That is the precise area that needs to be focused on for TMS treatments. The area of the brain that focuses on mood regulation is known as the left dorsolateral prefrontal cortex. The concentrated magnetic fields in the TMS coil pulse at high speed. The magnetic fields go on-and-off repeatedly, delivering the required treatment in much the same way as an MRI machine does. Unlike MRIs, the depth of penetration for TMS is minimal – 2 cm – 3 cm below the target surface.

Minuscule electrical currents are created as these magnetic waves pass into the brain, affecting the areas responsible for regulating mood. The currents result in neurotransmitter reactions which emulate dopamine, serotonin, and norepinephrine. It is a widely held belief that depression is a result of chemical imbalances in the brain, and the stimulation through TMS is geared towards restoring the chemical balance and relieving symptoms of depression.

Risks and Side Effects of TMS Treatments

Repetitive transcranial magnetic stimulation is effective for treating depression. Since there is no surgery required, it is generally considered a safe treatment. The side effects are minimal and include the following:

• A mild headache
• Dizziness or lightheadedness
• Temporary twitching or spasms of facial muscles
• A tingling sensation at the site of the TMS stimulation

Fortunately, the side-effects generally resolve on their own, quickly after treatment has stopped. It is possible to reduce the intensity of the TMS stimulation to lessen the risks and side effects. If the treatment is not well tolerated in patients, which is rare, the following side effects may occur:

• Seizures have been reported
• People with bipolar disorder may experience mania
• Hearing loss in the absence of adequate ear protection

Typically, patients are required to have 20 minutes – 40 minutes sessions 5 days a week, for 2 weeks – 4 weeks at a time. The UNC School of Medicine Psychiatry advised that relief from symptoms of depression is not noticeable until at least the third week of TMS treatment. It should be stressed that there is no pain and no systemic side effects associated with TMS treatments. Further, the non-surgical nature of the treatments does not warrant anesthesia, incisions, sedation, or recovery.

Different mental health conditions require different forms of treatment. In this sense, there are patented coil structures for major depression and obsessive-compulsive disorder. The orientation of the inner components of the helmets is designed to treat the specific conditions more accurately and effectively. By targeting the areas of the brain with improperly functioning neural activity, TMS devices can generate more productive responses.