LIFU FOR PSYCHIATRIC DISORDERS ANDI

LIFU FOR PSYCHIATRIC DISORDERS ANDIMPAIRED CONSCIOUSNESSThe introduction of LIFU, an incisionless brain stimulationmodality that influences brain activity through subthermaltemperature increases, presented a new opportunity to reversiblyexplore psychiatric disorders related to perception, emotion,and cognition along with altered states of consciousness. Oneof the first reports of the effects of transcranial ultrasoundwas 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 LOGIQeultrasound imaging system with an 8-MHz probe placed overthe frontal-temporal cortex contralateral to the side of maximalpain 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 0.7and a thermal index of 0.5, well below the FDA guidelines of1.9 for mechanical index and 6.0 for thermal index. Patients inthis study reported significant improvements in mood (measuredwith the Global Affect score derived from the Visual AnalogMood Scale) both 10 min and 40 min after FUS compared to thesham session.