Transcranial Magnetic
Stimulation
Non-invasive neurostimulation using targeted magnetic pulses for treatment-resistant depression and other psychiatric conditions, in Lausanne, Switzerland.
What is TMS?
Repetitive transcranial magnetic stimulation (rTMS) delivers intense magnetic pulses through a powerful electromagnet placed on the surface of the skull. The exact positioning is determined using the patient’s brain MRI through a device called a neuronavigator.
The dynamic magnetic field produces a low electric current, imperceptible to the patient, through electromagnetic induction, in precise brain areas and circuits involved in depression and other psychiatric or neurological conditions.
Brain cell activity is modified — increased or decreased. TMS causes an increase in blood flow, glucose metabolism and the concentration of certain neurotransmitters (GABA, glutamate, dopamine).
The most common positioning for depression is the left or right dorsolateral prefrontal cortex, with the choice of area and parameters depending on each patient’s characteristics.
TMS does not require anaesthesia and is not painful. At most, it may cause mild headaches that respond well to standard analgesics. TMS is also a diagnostic tool in certain neurological diseases.
Who is TMS indicated for?
TMS is indicated for the treatment of forms of treatment-resistant depression or in cases of sensitivity or side effects to medications, in patients of all ages.
Other promising indications:
- Addictions (particularly cocaine)
- Post-traumatic stress disorder (PTSD)
- Obsessive-compulsive disorder (OCD)
- Certain symptoms of schizophrenia (auditory verbal hallucinations, negative symptoms)
- Fibromyalgia and chronic pain
- Tinnitus
- Rehabilitation after stroke
TMS can be combined with or followed by ketamine infusions for patients requiring a multimodal interventional approach.
Is TMS effective?
In cases of antidepressant treatment failure, TMS has demonstrated significant efficacy in numerous studies (more than forty).
TMS has an efficacy at least comparable to that of antidepressants. Electroconvulsive therapy (ECT) remains more effective, however it is also more burdensome as it requires general anaesthesia for each session.
TMS is approved for treatment-resistant depression in several countries, including the United States and the United Kingdom.
When TMS alone does not achieve sufficient improvement, ECT remains the most effective interventional treatment for severe forms of treatment-resistant depression.
Treatment procedure
The patient is comfortably seated in a chair. All metal objects sensitive to magnetic waves are removed. Adhesive markers are placed on the head to enable optimal positioning of the coil using the neuronavigation device.
A “motor threshold measurement” procedure is carried out at the beginning of the first session to personalise the treatment intensity. The coil is then placed on the target area.
For depression, the protocol involves cycles of repeated pulses for several seconds with free intervals. The duration of the most common protocol is approximately 40 minutes. During treatment, the patient hears a series of “clicks” and feels a tapping sensation on the surface of the skull.
Typical schedule
Initial phase: one daily session, 5 days a week, for a minimum of 2 weeks. Maximum efficacy in 4 to 6 weeks.
Accelerated protocols: several sessions per day for 1 to 2 weeks.
Maintenance: spaced sessions if needed.
Theta Burst Stimulation (TBS) reduces session duration to less than 10 minutes with comparable efficacy.
The first session is always carried out by a physician. TMS protocols are designed and supervised by Dr Mall, using MRI-guided neuronavigation for optimal targeting.
Side effects
TMS has none of the typical side effects of antidepressants: no weight gain, sexual dysfunction, gastrointestinal problems, drowsiness, insomnia, dry mouth or excessive sweating. It does not cause memory or concentration problems either.
The most common side effect (approximately 10% of cases) is a mild headache or discomfort during treatment, easily managed with standard analgesics. This effect is generally mild to moderate and diminishes over sessions.
It is extremely rare for patients to discontinue treatment due to side effects.
Risks and contraindications
As with MRI, TMS uses an intense magnetic field and cannot be used in the presence of an implanted metal device in the skull or within 30 cm of the stimulation area (exception: dental crowns and amalgams).
Contraindications (non-exhaustive list)
- Aneurysm clips
- Implanted brain stimulators
- Brain monitoring electrodes
- Metal implants in the ears or eyes
- Bullet or shrapnel fragments in or near the head
- Facial tattoos with metallic or ferromagnetic ink
- Pacemakers or implantable defibrillators (in some cases)
The main risk, extremely low (0.1% of patients), is inducing an epileptic seizure. This risk is considerably reduced by strict adherence to safety guidelines and the use of individualised stimulation parameters.
Insurance coverage
In Switzerland, transcranial magnetic stimulation, particularly neuronavigated, remains a highly innovative treatment that is rarely used for depression, unlike in English-speaking countries.
TMS is currently not covered by basic health insurance or supplementary insurance. Sessions are therefore at the patient’s expense.
Further information regarding fees and payment arrangements is available upon request.