Repeated scans of patients suffering from the mysterious ailment commonly known as “Havana syndrome” found no significant evidence of brain injury, according to an ongoing investigation by the National Institutes of Health (NIH).
Two studies, published Monday in JAMA, found few significant differences in a range of cognitive and physical tests among more than 80 patients who had been stationed in Cuba, Austria, China, and other locations compared with a control group of people with similar job descriptions.
The researchers said they did not seek to find the origin of the ailments, which the U.S. government refers to now as “anomalous health incidents” (AHIs). Nor did the NIH researchers seek to disprove conjectures, which have received extensive media coverage, that American officials were attacked by an unidentified foreign adversary using some kind of newly invented pulsed-energy weapon.
The focus instead was on the physical condition of the patients, including whether they showed signs of injuries or brain damage.
The new findings are poised to reignite the controversy over this now-global medical mystery, which sparked a rash of inconclusive investigations, roiled the State Department and Central Intelligence Agency, and heightened tensions between the United States and Cuba. While the NIH study is unlikely to resolve the politically charged debate, it might intensify doubts in the scientific and intelligence communities regarding the existence of unidentified adversaries targeting government officials with an exotic weapon.
The researchers emphasized that the patients who volunteered for the study, which began in 2018, do have severe symptoms that can be debilitating.
“These symptoms are real, and they feel it, and we acknowledge it,” said Leighton Chan, lead author of one of the papers. “We have a third of our cases that either are not working or are struggling to work.”
The researchers believe their findings should be viewed as good news because these patients do not show evidence of brain damage, and many are already showing signs of improvement in their symptoms.
Two earlier studies, also published in JAMA, reported that brain scans of some patients showed unusual characteristics compared with controls. The NIH reports said the new data do not support those earlier findings.
Real symptoms, unknown cause
The JAMA papers are the latest attempt by medical and national security experts to explain the rash of ailments that got its nickname following a number of State Department officials in late 2016 reported mysterious symptoms while stationed in or near the U.S. Embassy in Havana.
The patients complained of intrusive sounds and head pressure, followed by a broad range of symptoms, including dizziness, pain, blurry vision, tinnitus, fatigue, nausea, and cognitive dysfunction. Some said they heard a buzzing or high-pitched sound immediately before feeling ill.
As media reports proliferated, some national security officials speculated that Russia or some other adversary had developed a secret pulsed