Background.
Transcranial Magnetic Stimulation is a noninvasive research tool used to study human motor physiology. It was initially developed by scientists in the 1980s as a means for neuro-diagnosis, nerve fiber study, and the development of a functional brain map.
TMS is also known as rTMS, or Repetitive Transcranial Magnetic Stimulation, cortical modulation, magnet therapy, magnetic stimulation and neuropsychology.
rTMS is foremost used to decrease symptoms of anxiety and depression, by using magnetic pulses to stimulate nerve cells.
Source.
In 1881 English physicist Michael Faraday discovered the physical properties of TMS when he observed that “a pulse of electric current passing through a wire coil generates a magnetic field.” In a paper entitled “Transcranial magnetic stimulation: a historical evaluation and future prognosis of therapeutically relevant ethical concerns,” researchers Horvath et al. discuss historical sources and modern application of TMS therapy. They explain, “During TMS, the stimulating coil is held over a subject’s head and produces an electric current in the subject’s brain via electromagnetic induction. This current depolarizes neurons and can generate various physiological and behavioral effects depending on the targeted brain area. Because magnetic fields can pass through the skull with almost no resistance, TMS can induce relatively large currents in targeted cortical areas.” To most folks, the thought of sending electrical pulses through the brain can sound intimidating. So, why consider something that sounds so insidious?
Medical Conditions This Can Treat.
rTMS is not a quick-fix for any medical or mental health disorder, but it has been shown to be effective in treating the following health issues:
- Amyotrophic lateral sclerosis (ALS) [Link here]
- depression [Link here]
- chronic and neuropathic pain syndromes [Link here]
- dystonia [Link here]
- migraine headache [Link here]
- mood disorders [Link here]
- Parkinson’s disease [Link here]
- post-stroke aphasia and hemiplegia [Link here]
- schizophrenia [Link here]
- spasticity associated with spinal cord injury [Link here]
- tinnitus [Link here]
Although there is a lack of scientifically and medically approved anecdotal evidence to support these claims, TMS is still intermittently used to treat these conditions.
Dose.
Electrical pulses may sound painful, but rTMS is relatively painless and carries a spectrum of benefits. Johns Hopkins University Medicine describes how TMS is administered “using an insulated coil placed over the scalp, focused on an area of the brain thought to play a role in mood regulation. The coil generates brief magnetic pulses, which pass easily and painlessly through the skull and into the brain. The pulses generated are of the same type and strength as those generated by magnetic resonance imaging (MRI) machines. When these pulses are administered in rapid succession, it is referred to as “repetitive TMS “ or “rTMS”, which can produce longer lasting changes in brain activity.”
Cautions.
Most physicians consider rTMS to be a safe and reliable procedure. There are, however, certain groups of patients whom rTMS is not suitable for. This group includes those with permanent metal implants in their heads or within 12 inches of the coil’s reach. Adherence to this rule is of the utmost importance, as failure to do so may result in serious injury or death. Johns Hopkins University Medicine suggests that patients with the following medical implants should refrain from receiving rTMS treatment:
- Aneurysm clips or coils
- Stents in the neck or brain
- Implanted stimulators
- Cardiac pacemakers or implantable cardioverter defibrillator (ICD)
- Electrodes to monitor brain activity
- Metallic implants in your ears and eyes
- Shrapnel or bullet fragments in or near the head
- Facial tattoos with metallic or magnetic-sensitive ink
- Other metal devices or object implanted in or near the head
Side Effects.
While TMS is a safe procedure, it is important to note that because it is a new treatment, there may be associated risks. Common side effects from the treatment include mild headaches, which generally diminish over time and can be treated easily with over-the-counter medications.
A small portion of patients, approximately one-third according to Johns Hopkins, experience “painful scalp sensations or facial twitching with TMS pulses.” These, too, typically diminish over time, and small adjustments can be made during treatment to account for and reduce this discomfort.
The TMS machine produces a loud clicking noise. For safety reasons, earplugs are given to the patient to use during the treatment. Some patients have reported mild, temporary hearing problems post-treatment. However, “no evidence suggests these effects are permanent if earplugs are worn during the treatment.”
The most serious risk of rTMS therapy is seizures, although that risk is significantly low.
Other Information.
To date, evidence suggests patients who may benefit most from rTMS treatment are those categorized as less treatment-resistant. However, because rTMS is relatively new, researchers and physicians are aware that particular, and potentially unforeseen, variables exist which require further study. Ongoing studies continue to appraise the many benefits of rTMS therapy, as well as identify patient groups most likely to benefit from it. Would you like to learn more about rTMS and similar treatments? Comment below and let us know!
