The Science Behind TMS

Principles of TMS  

Understanding the Brain’s Electrical System

Our brains function through a network of cells called neurons, which communicate via electrical impulses known as action potentials. The flow of action potentials along a succession of neurons carries information throughout the nervous system. This electrical activity forms the basis of our cognition, emotions, and behaviour. TMS works by influencing this electrical system in a targeted way.

How TMS Affects Electrical Activity in the Brain

TMS uses a specially designed magnetic coil, placed on the scalp near a specific brain region, that emits short bursts of a magnetic field. This field painlessly passes through the skull and induces an electrical current in the underlying neurons, increasing or decreasing their activity, depending on the stimulation pattern.

The therapeutic outcome of TMS depends on several key factors:

• Coil placement: Determines which brain region is targeted.
• Frequency of pulses: High-frequency stimulation increases brain activity; low-frequency may decrease overactivity. 
• Intensity: The intensity of pulses can also determine whether neural activity is increased or inhibited. 
• Treatment frequency and duration: The number of TMS sessions will affect the overall impact of treatment and how long the benefits last.

What Conditions Can TMS Treat?

Currently, TMS is FDA-approved to treat several conditions, including treatment-resistant depression (TRD), depression with co-occurring anxiety, obsessive-compulsive disorder (OCD), and substance use disorders.

TMS is also used “off-label” to support conditions such as generalized anxiety disorder (GAD), chronic pain, and post-traumatic stress disorder (PTSD). While the FDA has not formally approved TMS for these specific conditions, growing clinical research supports its effectiveness. Patients can receive TMS for these off-label purposes if a licensed medical professional determines it’s appropriate.

Different Types of TMS Treatment

What Is rTMS?

Repetitive Transcranial Magnetic Stimulation (rTMS) is the most commonly used form of TMS in mental health treatment. RTMS involves the delivery of magnetic pulses in rapid sequences, which can cause lasting changes in brain activity.

A standard rTMS protocol includes:

• Daily sessions (Monday to Friday)
• 20–40 minutes per session
• 4–6 weeks of treatment

Other TMS Protocols

As well as rTMS, other advanced TMS treatments include:

• Theta Burst Stimulation (TBS):  TBS delivers short bursts of high-frequency magnetic pulses, repeated five times per second (5 Hz). This method can achieve therapeutic effects in as little as 3–10 minutes per session.
• Continuous TBS (cTBS): CTBS applies the same burst pattern continuously without pauses, usually for 40 seconds to a minute. This results in a suppressive effect on brain activity. 
• Deep TMS (dTMS): DTMS uses specialized coils to reach deeper brain structures.
  Accelerated TMS: Accelerated TMS condenses the overall treatment timeline by delivering multiple sessions per day, often spaced an hour apart.
  
  

The Biological Mechanisms of TMS

Changing Electrical Activity

TMS directly influences the brain’s electrical system by depolarizing neurons. Depolarization means the neuron’s state changes, making it more likely to fire an electrical signal. This is especially beneficial for activating brain areas that are underactive in certain mental health disorders, such as the dorsolateral prefrontal cortex (DLPFC) in depression.

Through influencing electrical activity, TMS also impacts functional connectivity–which is how different brain regions interact. In many psychiatric disorders, such as depression, these communication patterns become disrupted. Brain imaging studies have shown that TMS can change the activation of these patterns, potentially restoring more normal brain network function. A study of depressed patients found that functional connectivity changes were associated with improved symptoms following TMS.

Balancing Neurotransmitters

Neurotransmitters are molecules that act as chemical messengers throughout the nervous system. TMS has been shown to increase the release of certain neurotransmitters, including:

• Serotonin: Regulates mood and sleep
• Dopamine: Influences motivation and pleasure
• GABA: Has a calming effect

Neurotransmitters play a key role in the development of mental health disorders. For instance, people with depression often have low levels of serotonin, while those with anxiety may have reduced levels of GABA. TMS may help by restoring the balance of these neurotransmitters, which could contribute to its therapeutic effects.

Enhancing Blood Flow

Cerebral blood flow refers to blood movement through the brain, delivering essential nutrients and oxygen needed for brain cells to function optimally. When this flow is impaired, brain cells may not receive enough oxygen to produce energy efficiently, which can contribute to impaired brain health and the development of psychiatric disorders. Research suggests that TMS can increase blood flow in specific brain areas, potentially supporting the recovery of neurons and improving their function.

Promoting Neuroplasticity

Neuroplasticity is the brain’s ability to adapt and reorganize itself in response to experiences, learning, or injury. In many mental health conditions, neuroplasticity is reduced, which may contribute to rigid and unhealthy patterns of thinking and behavior. Research shows that TMS can enhance measures of neuroplasticity, potentially aiding new neural connections and the ability to “break free” from negative thinking patterns and habits.

Safety and Side Effects of TMS

TMS is widely considered safe, with a low risk of serious side effects. However, there are common mild side effects, which include:

• Scalp discomfort or mild headache
• Facial muscle twitching during treatment
  Temporary fatigue or dizziness

These typically resolve on their own or lessen after the first few sessions. 

While TMS is generally considered safe, there are some rare but more serious risks. These include seizures, significant and lasting changes in hearing, and mood disturbances such as mania. However, these adverse effects are extremely uncommon, and thorough screening procedures help ensure that individuals at higher risk are not selected for treatment.

TMS Therapy at True North Integrative Mental Health

At True North, we’re a leading provider of TMS in North Carolina, specializing in TMS for depression. Our highly skilled TMS providers are here to ensure your safety and well-being during each step of your journey. Treatments take place in our relaxing clinic, using modern state-of-the-art equipment. If you want to learn more about our services, get in touch today.