TMS: The Latest Advancements and More!
TMS is by all accounts a pretty remarkable technology. It offers safe, effective, and drug-free relief from treatment-resistant forms of depression and anxiety. But as far as TMS technology has come in the past three decades, researchers and clinicians are continually looking to improve the treatment further! Academic and commercial research seems to be published almost constantly, documenting new applications and modifications of TMS devices and techniques. In this article, we want to lay out some of the latest advancements in TMS technology and detail the future directions of TMS.
Theta Burst Stimulation:
Theta Burst Stimulation is a relatively recent advancement in TMS technology that has been rapidly adopted by clinicians. The technique was first employed in European clinics, but has now made its way to the US. Just like conventional rTMS, theta burst therapy uses magnetic energy to stimulate the prefrontal cortex of the brain and improve depressive symptoms. The difference lies in how the stimulation is delivered. The Theta Burst protocol delivers stimuli in a unique pattern—three rapid bursts of pulses at 50 Hz, repeated every 200 ms. Compared to the conventional rTMS that uses a lower frequency, single pulses with inter-episode intervals. As a result, the treatment time is greatly reduced with Theta Bursts. Theta Burst Stimulation only takes 4 minutes, and research shows that it works equally well, if not better, than standard protocols that take upwards of 20 minutes.
Here at South Bay TMS we have begun to implement this protocol with great success. Our patients now have the option to receive both the Theta Burst and the conventional rTMS protocol in a single treatment—doubling the effective stimulation each patient receives. We believe that this, in part, is how come our patients have been so successful in achieving remission.
Current research is also underway to develop new TMS devices that use multiple magnetic coils. One such investigational device, now in clinical trials, is produced by the company Cerval Neurotech. The device utilizes a property referred to as spatial summation, where the magnitude of the multiple magnetic waves sum together. In theory, this property allows the new device to directly stimulate deeper structures in the brain and achieve higher circuit-level specificity in the brain. Although unpublished, the company reports that the pilot clinical trials to date have produced positive statistical and clinically relevant results.
Precision TMS with Structural MRI:
Incorrect placement of the magnetic coil on the patient’s cranium remains a common issue with TMS delivery. If the magnet is placed incorrectly, the target region of the brain will not be stimulated and no therapeutic effect will be observed. In current TMS protocols, coil placement is approximated using the relative location of the primary motor cortex, but a number of factors, including practitioner error and patient-specific anatomy, can lead to errors in this placement.
However, there are new TMS devices being developed, which incorporate sophisticated MRI-based navigation within their designs to enhance the precision of coil placement. These devices would eliminate these kinds of procedural errors, by effectively providing the physician with a detailed map of each patient’s brain.