Efficacy of Deep TMS with the H1 Coil for Anxious Depression

(1) Background: While the therapeutic efficacy of Transcranial Magnetic Stimulation (TMS) for major depressive disorder (MDD) is well established, less is known about the technique’s efficacy for treating comorbid anxiety. (2) Methods: Data were retrospectively analyzed from randomized controlled trials (RCTs) that used Deep TMS with the H1 Coil for MDD treatment. The primary endpoint was the difference relative to sham treatment following 4 weeks of stimulation. The effect size was compared to literature values for superficial TMS and medication treatments. (3) Results: In the pivotal RCT, active Deep TMS compared with sham treatment showed significantly larger improvements in anxiety score (effect size = 0.34, p = 0.03 (FDR)) which were sustained until 16 weeks (effect size = 0.35, p = 0.04). The pooled effect size between all the RCTs was 0.55, which compares favorably to alternative treatments. A direct comparison to Figure-8 Coil treatment indicated that treatment with the H1 Coil was significantly more effective (p = 0.042). In contrast to previously reported studies using superficial TMS and medication for which anxiety has been shown to be a negative predictor of effectiveness, higher baseline anxiety was found to be predictive of successful outcome for the H1-Coil treatment. (4) Conclusions: Deep TMS is effective in treating comorbid anxiety in MDD and, unlike alternative treatments, the outcome does not appear to be adversely affected by high baseline anxiety levels

Stimulation volumes V₁₀₀ (cm³), stimulated depth d₁₀₀ (mm) and maximal electric field values E_max (V/m) in the brain for simulations in 22 head models, 2 spherical models and for phantom measurements.

Shown are results of comparison of stimulation volumes V100 in the brain between the D–B80 and H7 coils using Wilcoxon matched–pairs test.</p

Comparison of electric field decay profiles.

Results of comparison of the electric field decay profile with distance between the D-B80 and the H7 coils using Wilcoxon matched-paired test, for simulations in 22 head models. (DOCX)</p

Colored maps of electric field distribution on a central perpendicular slice.

Colored field maps for the D-B80 coil (top row) and for the H7 coil (bottom row) showing electric field distribution on a slice perpendicular to the coil center, when located at the treatment location over the prefrontal cortex, indicating the electrical field absolute magnitude in each pixel. The red pixels indicate field magnitude ≥ the threshold for neuronal activation, which was set to 100 V/m. Shown are results for the 14 numerical head models and the two spherical models. (TIF)</p

Colored maps of electric field distribution on a central perpendicular slice.

Colored field maps for the D-B80 coil (top row) and for the H7 coil (bottom row) showing electric field distribution on a slice perpendicular to the coil center, when located at the treatment location over the prefrontal cortex, indicating the electrical field absolute magnitude in each pixel. The red pixels indicate field magnitude ≥ the threshold for neuronal activation, which was set to 100 V/m. Shown are results for the 8 PHM v.2 simulated head models. (TIF)</p

Field decay profile.

The electric field magnitude as a function of the distance from the coil, is shown for the D-B80 coil and for the H7 coil, when located at the treatment location over the prefrontal cortex. The field was measured along a line in a central sagittal plane starting at the point of inflection of the frontal bone and going at 45° downward and posteriorly (top left). The electric field was normalized to the field at a depth of 3 cm from coil surface. Shown results for the 8 PHM v.2 simulated head models. (TIF)</p

Distribution of values of EF intensity.

Histograms of distribution of the volume in cm3 according to the induced electric field range within the brain for the D–B80 and H7. Field columns are in bins of 5 V/m. The distribution of field values within the brain is significantly different between the coils (p = 0.002, Wilcoxon matched–pairs test).</p

Distribution of values of EF intensity within specific brain regions.

Histograms of distribution of the volume in cm3 according to the induced electric field range for the D–B80 and H7 coils, are plotted for five brain regions (dACC, dlPFC, IFG, OFC and pre–SMA). Field columns are in bins of 10 V/m. Shown the averaged results of all the 22 simulated head models.</p

Electrical conductivity (S/m) values used for the PHM models simulations.

(DOCX)</p