Transcranial Magnetic Stimulation (TMS) Therapy

Background

Starting a TMS Treatment Protocol

On 4-13-23 we started TMS. Steve scored 21/27 on the PHQ9, consistent with severe depression. On the GAD7, a survey for tracking anxiety, he scored 16/21, which was in the moderate-to-severe range.

We determined his motor threshold (MT) at 29% for TMS sessions and stimulated his left dorsolateral pre-frontal cortex (in simpler terms, the left side of the head, close to the forehead). I prescribed the commonly used (and FDA-approved) protocol of standard TMS at 10 Hz, frequency, totaling 3000 pulses per session.

Adjusting TMS Dose & Using FDA Guidelines as a Map

The FDA guidelines for treatment of resistant depression with TMS recommend a dose of 3000 pulses/per session at 10 Hz frequency. When we talk about dosing a medication, we take into consideration the amount the patient is given (i.e. 40 Mg of Prozac) and the frequency (i.e. once daily, twice daily, etc). In TMS parlance, pulses are akin to Mg and we use the term Hertz (Hz) o indicate the frequency at which pulses are delivered.

As already mentioned, guidelines say one can deliver a complete course of TMS at a dose of 3000 pulses per session and that’s what usually happens at large TMS clinics that operate like efficient factories following a franchise model all over our country. But our approach is different in that FDA guidelines are followed as a beginning point and if the patient needs more (that is, more electromagnetic pulses), then we go ahead and administer them.

Back to Steve – by day 11, PHQ9 had dropped from 21 to 11, which is pretty good, but still in the moderate range. We proceeded to increase the pulses to 4000 pulses at 10 Hz frequency on the left side of the brain. By day 17 PHQ9 creeped back up to 12 and we further increased pulses to 5000 per session, almost twice as much as the basic FDA recommendations. On day 23, PHQ9 was still 12. So, we added a second TMS modality called iTBS, or theta burst, providing an additional 600 pulses.

At this point, Steve was receiving 5000 pulses + one iTBS treatment which each equals a total of 5600 pulses per session (almost two standard 3000-pulse sessions). This part of the treatment was intended to stimulate the left, but we also added treatment on the right side (600 pulses at 1 Hz on the right).

Why? Well, Depression & anxiety often run in tandem, and neuroscientists and researchers think it’s caused by decreased activity on the left side and increased activity on the right side. The left side of the brain, we want to stimulate it with high frequency TMS (10 Hz) while the right side of the brain - we want to inhibit it and that is possible with lower frequencies (1 Hz).

At session 36 he still has symptoms and we requested an additional 15 sessions from his insurance. Luckily, it was approved and continued treatment for a total of 51 sessions.

This approach of boosting the left side and inhibiting the right side proved beneficial for Steve. If we had stuck to FDA guidelines AND not request more sessions from his insurance, we may have not gotten the results we achieved.