HONOLULU (August 10, 2017) - Lt. Col. Brian C. McLean (center), chief of the Interdisciplinary Pain Management Clinic, Tripler Army Medical Center, also known as Tripler, and Valerie R. Hall (left), Tripler licensed practical nurse, perform a stellate ganglion block procedure at Tripler's Interdisciplinary Pain Management Clinic on a U.S. Army active-duty soldier (right). In the procedure, a local anesthetic is injected into a bundle of nerve cells and nerves on the right side of the neck that help regulate the body's fight or flight mechanism. This procedure is being tested for its effectiveness in treating PTSD symptoms in a clinical trial currently underway at Tripler Army Medical Center, Womack Army Medical Center and Landstuhl Regional Medical Center. For more information, visit the stellate ganglion block for PTSD symptoms study website at https://sgbstudy.rti.org/.