Targeted Deep TMS for Prefrontal Cortex

After insertion of earplugs, the individual resting motor threshold (rMT) was determined by locating a “hot spot” on the motor cortex for stimulation of the right abductor pollicis brevis using single pulses at 0.2 Hz. For treatment the H-coil was advanced 6 cm anteriorly over the prefrontal cortex, with the H1 (labeled as “A”) remaining over the LPFC and the H7 coil (labeled as “B”) adjusted to a centralized position before treatment. Patients and operators were not aware of the differences between coil A and B. The rMT was rechecked at least once a week. Treatment intensity was 120% of rMT.
During 4 consecutive weeks (5 sessions/wk; Figure 1) patients were treated daily while during the 2 additional weeks patients were treated biweekly (with at least 48 hours between treatments). Patients in both treatment groups received a similar Deep TMS protocol (120% of rMT, 18 Hz, 2 seconds on and 20 seconds off over a 20-minute period; total of 1,980 stimuli per session), applied over the lateral (H1 coil) or medial (H7 coil) PFC. Maps of the electric field distribution generated in both treatment modes are provided in Supplemental Figure 5.