The nuts & bolts of TMS therapy
Deep TMS Therapy: A Non-Invasive Non-Medication Treatment for MDD & OCD
What is TMS?
TMS stands for Transcranial Magnetic Stimulation. It’s a non-invasive treatment that delivers pulses of an MRI-strength magnetic field from a coil placed over the scalp. The magnetic field generated by this coil passes through the skull, and stimulates the neurons in a certain area of the brain to fire. For depression, a TMS device delivers a focused magnetic stimulation to the dorsolateral prefrontal cortex, an area known to be underachieve in depression, which then stimulates deeper brain pathways (i.e. limbic system structures) related mood in order to restore function in these areas.
What is TMS used for?
TMS was introduced in 1985 as a technology for externally probing brain activity. 30 years of research, and 10 years of clinical practice, have shown that stimulating pathways in the brain enough times daily over a set period of time causes treatment-resistant depression to get better at a significantly higher rate than with antidepressants. It received FDA approval as a treatment for depression in 2008, and for OCD in 2019.
It came to market as an alternative to electroconvulsive therapy (ECT), without the drawbacks of memory loss, and.. well.. having a seizure (ECT is done under general anesthesia due to the convulsions it induces).
TMS is carried out while the client is awake, sitting in a chair. Treatment sessions last about 20 minutes, and are typically given daily, five days a week, for about 4-6 weeks. TMS therapy has been given to over 25,000 individuals with depression to date.
A quick neuroscience refresher…
On your 42nd day of life, in the womb, your first neuron developed. During the next 120 days, your brain developed around 100 billion neurons at a rate of 9500 neurons per second. About 60 days before birth, neurons begin establishing connections with other cells. The brain triples in size the first year of life, but unlike any other organ in your body, your brain actually gets smaller after the age of 3.
“Neurons that fire together, wire together.” The connections/synapses used regularly become stronger, and those that are not used begin to weaken or disappear. By the time you’re 16, you’ve pruned around half of your synaptic connections (and hopefully made some new ones along the way). The brain generates 25 watts of power (enough to illuminate a light bulb), and uses 20% of the body’s energy (caloric intake), but makes up only 2% of the body’s weight. 90% of people have the Left side of the brain that is dominant (and even slightly bigger than the Right).
L Hemisphere
(Left is ‘linear’ & ‘logical’ & ‘lists’)
Sensory stimulus from R side of body
Motor control of R side of body
Speech, language, comprehension
Analysis & calculations
Time & sequencing
Recognition of words, letters, numbers
Left brain traits: Analytical, organized, cautious, following rules. Strong in math, science, jeopardy. Articulate. Attentive to punctuation, spelling. Decision made on proof.
R Hemisphere
Sensory stimulus from L side of body
Motor control of L side of body
Creativity, imagination, music; Spatial ability
Context & perception; Emotional expression; Recognition of faces, places, objects
Right brain traits: Daydreaming, deep thinkers, artistic, spontaneous, likely to follow gut feelings. Trouble finding words. Can see through lies/tricks — would make great survivor contestants. Need for feedback & reality checks. Intuitive, attentive to meaning, decisions based on feelings.
How effective is TMS?
For depression, TMS shows better results than traditional medication, with fewer and less severe side effects. Approximately 1/3 people experience complete remission from depression, and >50% have significant reduction in their symptoms.
What are the side effects of TMS?
During treatment, the patient hears a clicking sound, and feels a tapping sensation on the head. The most common side effect is mild discomfort at the treatment area during the session, that is typically temporarily and only during the first few days of treatment. There are no long term side effects from TMS.
What is the “brain mapping” session like?
The first treatment when starting TMS therapy is called the mapping session, where the “motor threshold” and the “treatment location” are determined.
“Treatment location”: Left DLPFC for depression, ACC for OCD
“Motor Threshold” determination: There’s a portion of the brain, running along the top of the brain from ear to ear, called the homunculus. In TMS, we call it the motor strip, and it controls movements on the opposite side of the body. If an area of the body has a greater degree of movement, such as the hands, then a larger part of the motor strip is devoted to the hands. Delivering a magnetic pulse to a specific part of the motor strip on the left side of the head causes a response in the right thumb and fingers in the form of a twitch (like a reflex from when a doctor taps on your knee). After taking some basic measurements on the client’s skull, the magnetic coil (or helmet) is placed on the moved forward in 1-2 cm increments
What are the side effects of TMS?
During treatment, the patient hears a clicking sound, and feels a tapping sensation on the head. The most common side effect is mild discomfort at the treatment area during the session, that is typically temporarily and only during the first few days of treatment. There are no long term side effects from TMS.
Who should consider TMS?
Individuals with depression who haven’t benefit from, or tolerated, prior medication
Those seeking a drug-free depression treatment
Individuals where systemic side effects from prescription anti-depressant medications could be especially problematic, such as weight gain, sexual dysfunction, nausea, dry mouth, and/or drug interactions
Those who need to drive themselves to and from treatment sessions (which cannot be done with treatments like ketamine or Spravato)
Who shouldn’t get TMS?
Individuals with any type of ferromagnetic metal in their heads (with the exception of braces, dental fillings, or titanium). Examples include: Aneurysm clips/coils; Stents in the neck or brain; Implanted electrodes; Deep brain stimulators; Metal plates or metallic implants
There aren’t any medications that contraindicated during TMS, but it’s important for treatment providers to keep tabs on certain health and dietary patterns throughout the course of TMS treatment, such as caffeine consumption, alcohol use, and sleep, as these can affect the “threshold” for the firing of neurons. Patients should also let their TMS provider know if their medication regimen changes at any time during treatment.
