Deep rTMS Vs. Surface rTMS: A Comparison

By in
Deep rTMS Vs. Surface rTMS: A Comparison

There has been increasing confusion regarding the specific “types” of TMS. This article will serve to briefly clarify what TMS is, how it works, and how different types of machines (called Transcranial Magnetic Stimulators) compare.

In general, the only important information to know at this point is that Transcranial Magnetic Stimulators have been around since the mid-1980’s. However, the first machine manufacturer to apply for FDA-approval (a quite daunting task https://www.accessdata.fda.gov/cdrh_docs/pdf8/K083538.pdf) was Neuronetics, who created the NeuroStar machine. This machine was the first ever to be sold to physicians for use in their respective practices (e.g., NOT for research) in 2008. To this day, NeuroStar sponsors a huge amount of advertising campaigns and TV commercials (https://www.youtube.com/watch?v=Vu6TcSMca2w), where they specifically tell patients to “ask for NeuroStar by name.” Very rarely is it clear that the NeuroStar machine is just anotherTranscranial Magnetic Stimulator. In general, NeuroStar, is a fine machine. The biggest problem with NeuroStar is that they charge the doctor between 20-65% of the cost of treatment each time they turn the machine on. This, in turn, drives up the cost of treatment for the patient, often making it difficult or impossible to NeuroStar providers to accept in insurance for the equivalent service. That means that, if a NeuroStar machine charges a doctor $80 per session, an individual receiving treatment can end up paying almost $3,000 to the machine manufacturer!

The second machine to come onto the market is an Israeli device called Brainsway. Brainsway stimulators use a large helmet that is placed on an individual’s head during the whole session. People who use Brainsway for TMS tend to advertise themselves as practicing “Deep TMS.” Deep TMS is sort of a misnomer, as it has not has been proven that the Brainsway machines actually hit a deeper portion of the brain than any other machine. It is the consensus of many scientists that Brainsway perpetuates the “Deep TMS” as a marketing tool, rather than a proven fact. Other articles online might create a false dichotomy by comparing “Deep TMS to rTMS” to further confuse the issue. All TMS machines for depression use repetitive TMS (rTMS). So, “Deep TMS” is in a sense a type ofrTMS.

One of the big advantages for using Brainsway machines was that the treatment length was shorter, administered in only 20 minutes compared to more than 35 minutes for other TMS machines. However, the FDA recently approved a newer TMS protocol, which involved a shorter treatment session for so-called “surface TMS” machines. This new protocol allowed physicians to decrease the inter-stimulation interval by about half, so that the treatment could be done in almost half the time.

To date, there are no studies which have shown significant differences in depression score changes when comparing Deep TMS to Surface TMS. Some review studies may report a negligible, non-significant difference, likely due to random error instead of good science. In an independent study published in The Journal of Neuropsychiatry and Clinical Neurosciences, Lonergan et al. (2017) compared patient and technician attidues compared to Deep TMS and Surface TMS devices. Not only did real patients report a greater decrease in depressive symptoms from Surface TMS compared to Deep TMS, but patients also reported significantly more confidence in Surface TMS devices. Similarly, practitioners for both devices reported that Surface TMS devices have less side-effects than Deep TMS, and thus, they are more likely to recommend Surface TMS over Deep TMS.

In terms of side-effects, “Surface TMS” used by machines such as NeuroStar, MagVenture, MagPro, and Neurosoft, has far less side-effects. The risk for seizure is about 1 in 10,000 (0.01%) and the headache incidence is about ~25%. Brainsway users have an almost triple risk of seizure, increased likelihood for headache, and increased application site pain. In addition, Brainsway users tend to complain of uncomfortable and hot helmets. Finally, the Brainsway “Deep TMS” device makes it difficult to treat other disorders, such as anxiety, by specifically targeting other parts of the brain.