When Iran fired a barrage of ballistic missiles at United States troops stationed at military bases in Iraq on January 8, initial reports claimed that not a single U.S. soldier had been injured in the assault. In fact, Donald Trump -- on that same evening -- posted a tweet.
"All is Well!" and "So far, so good!" he tweeted.
But about one week later, the estimate of casualties rose sharply, and on Friday, even that revised number more than tripled.
On January 16, Pentagon sources revealed that 11 U.S. service members had been transported out of Iraq to hospitals in Germany and Kuwait, where they were treated for traumatic brain injuries, or "concussion symptoms," as reported in a statement issued by the Defense Department at the time.
But on Thursday of this week, that estimate of casualties was called into doubt, when Defense Secretary Mark Esper spoke at a press conference at a Naval air base in Florida.
"I don't know those numbers," he said.
One day later, according to a CNN report, the Pentagon acknowledged that 34 U.S. soldiers suffered traumatic brain injuries in the January 8 Iranian missile strikes.
Of those service members, 17 have since been treated and returned to duty in Iraq. Of those 17, all but one were treated for their injuries locally, without being transferred to facilities out of the country, according to CNN.
An Associated Press report, however, details that nine of the injured soldiers remain in Germany, where they continue to be treated for their brain injuries, 16 days after the attack.
Eight more service members have been transported from Germany to the United States for further treatment or observation, according to the AP. Additionally, one soldier was transported to a medical facility in Kuwait -- Iraq's direct neighbor to the southeast -- but they have since returned to duty in Iraq.
When asked about the casualty reports earlier this week, at the World Economic Forum in Davos, Switzerland, Trump downplayed the significance of traumatic brain injuries. Instead, Trump said that he heard the soldiers suffered from "headaches," according to the AP report.
Trump added that he did not consider traumatic brain injuries to be as serious as other forms of combat injury, such as losing an arm or a leg.
The Centers For Disease Control (CDC), however, describes traumatic brain injury (TBI) as "a major cause of death and disability in the United States." According to the CDC statistics, in 2014, an average of 155 Americans died each day from injuries that included a TBI.
Symptoms -- which can sometimes pass quickly but can also last a lifetime -- include cognitive and memory impairments, as well as impairments to vision, hearing, and other functions. TBIs can also lead to serious emotional difficulties and even personality changes, according to the CDC.