What IS TMS (Transcranial Magnetic Stimulation)?
What is TMS (Transcranial Magnetic Stimulation)?
TMS is an innovative treatment that uses magnetic fields to stimulate neurons in the brain involved in mood regulation. This treatment has gained popularity because it is non-systemic (does not circulate in the bloodstream) and non-invasive (does not involve surgery). Additionally, it has been shown to be free of many side-effects that patients experience when taking medication. It is a method of electrically stimulating the brain through scalp without causing pain from direct electrical current. A stimulator produces in a coil over the scalp an MRI strength electrical field that is very brief. The electrical field has no effect on the skin and the bone, but the neurons in the brain are affected by that brief change in magnetic field. It effectively induces an electrical current in the the axons of those neurons in the cortex of the brain. Those neurons carry the message on through their cell body and on to their neighboring and connecting neurons.
What is Single Pulse TMS?
Single pulses produce fascinating but short lasting effects, usually less than 6 seconds. Although they may serve as diagnostic purpose in the future there is no therapeutic purpose to single pulse TMS.
Clinically, single pulses of TMS are used to measure the resting (or active) motor threshold. What is the motor threshold? It is the minimum TMS intensity (or stimulator power) necessary to induce a motor evoked potential (MEP) in 5 out of 10 trials.
What is a motor evoked potential (MEP)?
It is defined as the overall reaction of a peripheral muscle to TMS stimulation of the contralateral motor cortex. It is measured by the electromyography (EMG) as a wave with amplitude, latency and variance. Clinically (not in research) a visual motor response is used, usually a twitch of the finger or the toe.
What is repetitive TMS (rTMS)?
Repetitive TMS is when a series of pulses are used to create longer lasting effects. It can last anywhere from 30 minutes to years. The pattern of the pulses, the intensity (amount of power), the total number of the pulses, position of the coil, type of coil and more details are all factors that contribute to the lasting effects of rTMS. rTMS has been FDA approved for the treatment of depression since October of 2008.
What is Deep TMS ?
Deep Transcranial Magnetic Stimulation uses special combinations of coils that are capable of reaching 1.7 cm beneath the surface of the skull. They are called H coils, and they are manufactured by a company called Brainsway. Different H coils are designed to target different brain areas. Deep TMS with the H1 coil is FDA-approved for the treatment of depression in patients who tried any number of medications without improving. It is the safest treatment with the least side effects for patients with treatment resistant depression. Deep TMS is based on brief 20-minute sessions, which are almost half the time of other TMS treatments.
In Europe, Deep TMS is CE approved for the treatment of:
- Bipolar depression
- Chronic pain
- Major depression
- Post Traumatic Stress Disorder (PTSD)
- Smoking Cessation
- Multiple sclerosis
- Negative Symptoms of Schizophrenia
- Parkinson’s Disease
- Obsessive Compulsive Disorder
- Stroke rehabilitation
What is conventional rTMS?
Conventional rTMS uses magnetic coils that are flat, helical, double helix (figure eight) shaped or clam shaped. They reach 0.7cm below the surface of the skull. Several companies make these coils. The first FDA approved coil for depression was made by Neuronetics. Most of the research with rTMS was done with coils made by Magstim. Conventional rTMS is much more efficacious when it is used as an augmentation agent to medication.
What is the mechanism behind the antidepressant activity of TMS?
We don’t know all the ways TMS works, but it has local and distant effects. Locally, it increases the activity and excitability of neurons, increases blood flow and neurotransmitters in the dorsolateral prefrontal cortex. Deep TMS reaches a wider, deeper area including the the anterior cingulate cortex. According to studies, deep brain structures have more connections with the reward system, so that deep stimulation can generate effective results. TMS has distant effects through the neuronal networks that reach from the cortex all the way into the limbic system. Additionally, there is entrainment of the oscillations (rhythms of the brain waves) which are desynchronized in depression, a disorder of brain connectivity.
What are the side effects of TMS, rTMS, Deep TMS?
In order of frequency: Temporary scalp tenderness, temporary headache, temporary jaw pain, temporary tooth pain, rare incidence of seizure.
How Do We Use TMS clinically off label for psychiatric disorders?
Psychiatric disorders are primarily brain disorders. They are associated with areas of decreased activity or decreased activity, sometimes under specific circumstances. Obsessions, compulsions, phobias, addictions, all have associated changes in brain activity in specific regions. Treatment protocols are designed to first simulate the disease state (a provocation) and then normalize the abnormal brain activity with the ideal coil and rTMS protocol for that location.
How do we use TMS clinically off label for neurological disorders?
Neurological disorders are either disorders of the central or peripheral nervous system. They are associated with global or specific neuronal dysfunction. Parkinson disease, tinnitus, tic disorder, temporal lobe epilepsy, language or motor problems after a stroke are all examples of disorders with specific anatomical sites in the brain that can be targeted with specific coils. rTMS protocols are designed to excite or inhibit specific areas in the central nervous system. Neuropathic pain is a disorder for which TMS has excellent efficacy.
Excitatory versus Inhibitory TMS Protocols:
There are two rules of thumb that can be kept in mind for rTMS. Low frequency stimulation decreases cortical excitability and metabolic activity of those areas. For example, stimulating the motor cortex at 1HZ (1 pulse per second) for 1500pulses decreases the amplitude of MEP and increases motor reaction time for thirty minutes. This is called an inhibitory protocol. High frequency stimulation increases cortical excitability. A practical example of this is treatment for depression at 10HZ or higher. The excitability of the cortex is increased, the metabolic activity of the underlying neurons and connected networks are increased for a significant period of time. This is an excitatory protocol. The effects of an excitation protocol are always longer lasting than inhibitory protocol.
Why choose us for your treatment?
We have been using the technology since January 2009 and were one of the first sites in the US to deliver TMS. Since that time, we have treated several hundred patients with treatment resistant depression and have extensive experience in the off label application of TMS in other psychiatric and neurological conditions. Advanced Mental Health Care (AMHC) is also is one of the few facilities in the nation that have Three FDA-cleared devices – the Brainsway Deep TMS device, the Neurostar rTMS device and the Magstim rTMS device. We are continuously active in research related to brain stimulation and are up to date on the most effective treatment protocols.
Additionally, AMHC is the only clinical research site in the US working on dTMS and its application in mild cognitive impairment/pre-Alzheimer’s Disease.
Dr. Aron Tendler will supervise all of your care while receiving treatment. Dr. Tendler was a PI (Principal Investigator) on the studies that led to the FDA approval of the Brainsway dTMS device and is currently PI of several other studies (Bipolar Depression, OCD, Smoking Cessation,PTSD, MCI/Mild Neurocognitive Disorder). Our TMS operators are extremely well versed in the application of TMS.
For your convenience, we have machines in 3 different locations and are available 7 days a week for severely ill patients. For more information, or to schedule a consultation, please call 561-333-8884 or request a consultation online.
What should I expect?
You will first undergo a comprehensive evaluation with your psychiatrist to determine if TMS is clinically appropriate. This will include gathering a thorough history of previous medications and a review of the known risk/benefits of undergoing TMS for your condition. Once TMS has been determined to be the next best step in your care, the doctors will discuss the course of treatment, including location, frequency and duration. You will be awake and alert throughout each session. The technician will assess for side effects on a daily basis and you will follow-up on a regular basis with your psychiatrist.
For more information click below: