No evidence of Havana syndrome brain injury, US studies find

(Reuters) - A U.S. government research team found no significant physical evidence of brain injury in a group of federal employees suffering symptoms of the "Havana syndrome" ailment that emerged in 2016, according to studies published in a medical journal yesterday.

The National Institutes of Health (NIH) researchers also found no differences in most clinical measures between a group of 86 employees and their adult family members reporting unusual health incidents and a group of healthy volunteers with similar work assignments.

Symptoms of the mysterious ailment, first reported by U.S. embassy officials in the Cuban capital Havana and later afflicting diplomats, spies and other personnel worldwide, have included hearing noise and experiencing head pressure followed by headache, migraines, dizziness, and memory lapses.

"These individuals have symptoms that are real, distressing and very difficult to treat," Dr. Leighton Chan, NIH Clinical Center acting chief scientific officer and lead study author, said on a call to discuss the findings published in JAMA.

Study participants, including personnel who had been stationed in Cuba, China, Vienna and the United States, underwent a battery of clinical, auditory, balance, visual, neuropsychological and blood testing. They also received different types of MRI scans aimed at investigating volume, structure and function of the brain.

Mark Zaid, a Washington-based lawyer who has represented Havana sufferers, said the findings of no significant medical differences between the two populations after time had passed "do nothing to undermine the theory that a foreign adversary is harming U.S. personnel and their families with a form of directed energy."

An NIH spokesperson said the studies sought to identify structural brain or biological differences and did not seek to determine whether some external phenomenon was the cause of symptoms, nor could they rule that out.

"We understand that some patients may be disappointed that researchers were unable to identify clear markers of injury," the spokesperson said.