The Pentagon says that 34 service members have been diagnosed with concussion-like or traumatic brain injury (TBI) symptoms since the Jan. 8 Iranian ballistic missile strike on Al Asad Air Base in Iraq.
Jonathan Hoffman, Pentagon chief spokesman, said that eight troops who were initially sent to Germany arrived Friday in the U.S. to continue treatment; nine others are still undergoing treatment in Germany; one was sent to Kuwait for treatment and has since returned to duty in Iraq; and 16 who were diagnosed in Iraq have now returned to duty.
In total, 17 of the 34 have returned to duty. There is a "distinct possibility" that the nine still in Germany may head to the U.S. for further treatment, he said.
"We needed to have more clarity," Hoffman said, adding that the Pentagon wanted to get the facts straight on the troops' medical conditions. He explained that the Defense Department has been referring to concussion and TBI "relatively interchangeably."
"The numbers have shifted as more people have been diagnosed. [But] this is a snapshot in time of where we are right now," he said.
Defense Secretary Mark Esper has given instructions that "anyone who comes in with symptoms, receives any and all care that they need," Hoffman said. "We need to track that closely."
Whether the troops could receive the Purple Heart for injuries as a result of enemy action is under review. Hoffman said it's up to the individual military branches to make those decisions.
Last week, defense officials confirmed that 11 U.S. service members were flown from Iraq to U.S. medical facilities for additional evaluation and treatment of concussion-like symptoms. The Associated Press was first to report Tuesday that more troops were being evaluated in Landstuhl, Germany, for similar injuries.
Air Force Maj. Gen. Alex Grynkewich, deputy commander of Combined Joint Task Force-Operation Inherent Resolve at U.S. Central Command, this week said officials had estimated that the total number in need of evaluation was "in the teens."
According to a Department of Veterans Affairs study, a traumatic brain injury can go undiagnosed in its milder forms and result in issues for returning service members ranging from "headaches, irritability, and sleep disorders to memory problems, slower thinking, and depression."
Numerous reports and studies by the DoD and the VA have pointed to links between blast exposure and TBI and post-traumatic stress.
According to the DoD and the Defense and Veteran's Brain Injury Center, about 22% of all combat casualties from Iraq and Afghanistan involve brain injuries, compared with 12% of combat casualties in Vietnam.
Speaking at the World Economic Forum in Switzerland, President Donald Trump on Wednesday downplayed the injuries as "headaches."
"I heard that they had headaches, and a couple of other things," he said during a press conference. "But I would say, and I can report, that it is not very serious."
-- Richard Sisk contributed to this report.