Understanding Transcranial Magnetic Stimulation

​Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique that uses electromagnetic induction. A magnetic coil placed on the scalp connects to an electric pulse generator, also known as a stimulator, which generates a changing magnetic field that induces an electric current in a specific area of the brain.

This procedure helps improve neurological and mental health disorder symptoms. Examples of these conditions include anxiety, depression, obsessive-compulsive disorder (OCD), Parkinson’s disease, stroke, post-traumatic stress disorder (PTSD), and motor dysfunction resulting from multiple sclerosis. The U.S. Food and Drug Administration (FDA) recommends TMS if a patient doesn’t respond to psychotherapy or antidepressant medication.

Aside from mental health disorders, doctors can recommend TMS for migraines and smoking cessation when other standard treatments have failed. Notably, when used to treat depression, OCD, and smoking cessation, this procedure delivers repeated magnetic pulses, a procedure called repetitive transcranial magnetic stimulation (rTMS). There is also ongoing research to establish if TMS can treat other conditions like addiction, chronic pain, eating disorders, fibromyalgia, tinnitus, and stroke complications.

First introduced in 1985, TMS is now common in treating brain-related and mental health conditions. Electricity and magnetism are two physics principles that TMS uses. The procedure requires that the two work in conjunction. The brain is electrically active with brain cells and nerves using electrical signals to transmit information between the brain and to the rest of the body.

Introducing a magnetic field in the brain affects its electrical activity. This way, TMS can target specific brain parts responsible for emotions, feelings of pleasure, and decision-making, enhancing these functions for overall well-being. TMS uses an electromagnet, meaning that the magnetic field can be turned on and off precisely by a doctor or medical technician to achieve the desired effect.

There are four aspects of TMS. These include magnet strength, magnetic coil type, pulse frequency, and pulse patterns. A TMS’s magnets generate a magnetic field smaller than that of a magnetic resonance imaging (MRI) scanner.

There are different magnetic coil configurations, each targeting a specific brain structure. For instance, an H-shaped magnetic coil targets brain structures deeper than those rTMS treats, a procedure called deep TMS (dTMS).

When the magnetic field is turned on and off, it’s called a pulse. Frequency entails pulses per second measured in hertz. TMS may use a low-frequency pulse of about 1 hertz or a high-frequency pulse of from 5 hertz to 10 hertz.

Last, TMS can use different pulse patterns. For example, theta-burst stimulation (TBS) delivers three 5-hertz pulses per second, resulting in 15 pulses every second. This makes it five or six times faster than other TMS procedures, accelerating treatment.

Before undergoing TMS, a healthcare professional screens patients to ensure they meet the procedure’s criteria. For instance, if a person has an electronic implant containing magnetic metal or if they have epilepsy, seizures, or certain other conditions affecting the brain, they don’t qualify for the procedure. However, if a person does qualify, they are referred to a TMS specialist.

During a TMS session, a technician sits the patient on a comfortable chair and gives them earplugs to reduce the magnetic impulse clicking noises. The patient stays awake and doesn’t need any anesthesia. The technician begins by measuring the head to position the magnetic coil correctly and personalize the TMS machine's settings. Then they place the coil above the brain’s front part. The treatment begins, producing clicking sounds and a tapping sensation. Sessions last from 30 to 60 minutes. Afterward, the patient can drive home and resume normal activities.

Robert Harden

Shop