LIFU FOR PSYCHIATRIC DISORDERS AND

LIFU FOR PSYCHIATRIC DISORDERS AND IMPAIRED CONSCIOUSNESSThe introduction of LIFU, an incisionless brain stimulation modality that influences brain activity through subthermal temperature increases, presented a new opportunity to reversibly explore psychiatric disorders related to perception, emotion,and cognition along with altered states of consciousness. One of the first reports of the effects of transcranial ultrasound was published in 2013 and involved a double-blind crossoverstudy of patients with chronic back pain (105). In this study,patients underwent either FUS or a sham session on a LOGIQe ultrasound imaging system with an 8-MHz probe placed over the frontal-temporal cortex contralateral to the side of maximal pain for 15 s. Forty minutes later, patients were switched to theopposite treatment arm (FUS or sham) for the second session. The parameter selection produced a mechanical index of 0.7 and a thermal index of 0.5, well below the FDA guidelines of 1.9 for mechanical index and 6.0 for thermal index. Patients in this study reported significant improvements in mood (measured with the Global Affect score derived from the Visual Analog Mood Scale) both 10 min and 40 min after FUS compared to thesham session.