TMS means Transcranial Magnetic Stimulation. The term can be a little confusing since there is no actual magnet, rather a coil of wiring which sends out a magnetic field. We use this magnetic field to transfer a small electric field into your brain. This is just the physics Faraday taught us: every changing magnetic field induces a changing electric field.
A TMS electric field affects only a very small part of your brain area. But it does reach all the way down through your cortex, the top layer of “grey matter” in the brain. And that is important, because TMS needs to nudge those cells into action.
The best thing about TMS is that its effects are only on the brain. It is completely non-invasive and considered safe. There is no need for a needle or swallowing pills; magnetic fields simply pass through brain tissue, harmlessly.
When we use TMS to treat major depressive disorder (MDD), we send thousands of magnetic pulses into a precise region of the brain, a region doctors call the left dorso-lateral pre-frontal cortex (dlpfc). In people with depression, activity in this part of the brain is lower than normal.
What to expect?
TMS has been proven in clinical trials to be efficient in the treatment of major depressive disorder with approximately 50% of patients responding significantly to treatment and 15–37% of patients sustaining total absence of depression symptoms.
Neurons, the cells in the brain, communicate by “firing”, constantly charging and discharging. In other words, communication in the brain is based on electricity. Ultimately, the same electricity that TMS generates. TMS therapy works because each magnetic pulse creates a local electric field, just strong enough to activate the neurons in focus. As these neurons are now forced to fire, they activate other, nearby neurons and strengthen connections to other parts of the brain. So, you could say TMS speaks the same language as the brain itself.
Science has revealed that the human brain is constantly rewiring itself to either remember, or forget, new learning. That is why TMS therapy sessions are repeated over several weeks. Every new session teaches the brain to remember the new anti-depressant pathways TMS therapy has reawakened.
Your healthcare provider needs the tools to make sure the right dose of TMS therapy is given to the right part of the brain. That probably sounds obvious to you - and it sounds obvious to us, too. But not to everyone, perhaps because it is not so easy. Brains are like people, we are all individuals – and different. Targeting TMS requires an MRI scan of your head for the healthcare provider to see into your brain, and sophisticated software to model the complexity of your individual head. This is what Nexstim SmartFocus® TMS does. And it is unique.
INDICATIONS FOR USE
FDA: Nexstim Navigated Brain Therapy (NBT) System 2 is indicated for the treatment of Major Depressive Disorder in adult patients who have failed to achieve satisfactory improvement from prior antidepressant medication in the current episode. Nexstim NBT System 2 is intended to be used by trained clinical professionals.
CE mark : Nexstim Navigated Brain Therapy System for depression is intended to be used for treatment of major depressive disorder (MDD)
by targeting and delivering noninvasive repetitive TMS stimulation to the patient's dorsolateral prefrontal cortex.
NBT THERAPY SHOULD NOT BE GIVEN TO
- Patients with non-removable conductive, ferromagnetic, or other magnetic-sensitive metal anywhere in the head or within 30 cm (12 in) of the stimulation coil. Examples include cochlear implants, implanted electrodes or stimulators, aneurysm clips or coils, stents, bullet fragments, ocular implants, and stents.
- Patients who have an active or inactive implanted device (including device leads), including deep brain stimulators, cochlear implants, cardiac pacemakers, and vagus nerve stimulators. Contraindicated use could result in serious injury or death.
- Patients with increased intracranial pressure or patients with intracardiac lines, intravenous pumps, or dose calculators.
Failure to follow these restrictions could result in serious injury or death.
RISKS AND SIDE EFFECTS
Seizures (convulsions): Cortical magnetic stimulation runs the risk of inducing seizures; although they are rare. Under ordinary clinical use, the estimated risk of seizure is approximately 1 in 30 000 treatments (0.003%) or 1 in 1000 patients (0.1%).
Headache: The most common side effects reported during clinical trials are mild headache (~50% of TMS treatment group) and scalp pain or discomfort (35.8%). In general, headache and pain on the stimulation site have been generally mild to moderate and occurring less frequently after the first week of treatment. The reason for headache may be the tension of scalp and neck muscles due to an uncomfortable and stressful situation.
Muscle Twitching: You may feel twitches in the muscles of your arm, leg or face during the magnetic stimulation. This is a common sensation but not hazardous. The twitches will stop when the magnetic stimulation stops.
Skin Irritation: There is a small risk of mild skin irritation at the location where the muscle electrode sensors have been placed, but this usually consists of minor redness that will go away quickly after they are removed.
Changes in hearing: The loud “click” produced by the TMS stimulator can cause temporary hearing changes following treatment. This is prevented by wearing soft foam ear plugs during treatment. No problems with hearing due to TMS have ever occurred when earplugs have been properly worn
There is no evidence that single therapy sessions would improve mood. rTMS treatment effects in reducing depression are temporary, and patients may need to continue other forms of depression therapy. Relapse into depression is likely without follow-up treatment. Notify your doctor in case of worsening depression or suicidality.