A new US government study found no substantial evidence that “Havana syndrome” was caused by brain damage, further deepening the mystery surrounding the illness that emerged in 2016 among US personnel stationed overseas, Reuters reports.

The study was conducted by a group of researchers from the US National Institutes of Health (NIH) on a group of 86 US government employees and their family members who reported unusual symptoms.

The control group consisted of the same number of volunteers who worked on tasks similar to those who complained of “Havana syndrome”. But according to results published Monday in the journal JAMA, the researchers could find no difference between the two groups in most clinical measures.

The symptoms of this mysterious disease were first reported by US embassy staff in Cuba, hence the name “Havana Syndrome”, but have since been reported by US diplomats, spies, military and other government officials around the world.

Among the symptoms that have come to be associated with the disease are auditory hallucinations and pressure on the brain, usually followed by headaches, migraines, dizziness and memory problems.

“These people have symptoms that are real, worrisome, and very difficult to treat,” said Leighton Chan, NIH’s scientific director and lead author of the new study.

The study participants, who included US government employees stationed in Cuba, China, Austria and the United States, underwent a wide range of clinical, hearing, vision, balance, neuropsychological and blood tests.

The researchers also gave the study participants several nuclear magnetic resonance (MRI) scans to examine the volume, structure and normal functioning of the brain.

New study contradicts previous studies of “Havana syndrome”

But the results of the study, which was based on two surveys conducted between 2018 and 2022, contradict data from a separate study by scientists from the University of Pennsylvania. This study, also published in 2019 in the scientific journal JAMA, found some subtle changes in the brains of people who claim to suffer from “Havana syndrome.”

Dr. Chan now says that the NIH used stricter protocols for the MRIs performed and that the control group he used in his study was closer to the patients both in terms of their work and where they lived.

Dr. David Relman, a professor at Stanford University School of Medicine, noted in an editorial published by JAMA at the same time as the new study that some of the cases could be explained by exposure to radiofrequency energy.

He says there is a need for surveillance systems that can quickly detect early symptoms of “Havana syndrome” and the emergence of “outbreaks” of cases in various agencies and departments of the US government.

Dr Chan, in turn, said this approach could ease the anxiety and worry some federal government employees feel about the unknown condition.

NIH researchers found that more than a quarter of patients who report having “Havana syndrome” develop a chronic condition called persistent postural-perceptual vertigo. This disease is caused by a sudden change in the brain’s ability to interpret movements in space after a disturbing event and maintaining the state and after overcoming the moment of crisis.

The research team also reported a significant increase in symptoms of fatigue, post-traumatic stress and depression among people with “Havana syndrome” compared to control volunteers.

The US special services claim that the “Havana syndrome” is not the result of the actions of foreign countries

Louis French, assistant director of the Walter Reed Military Medical Center and one of the study’s authors, said the results from the MRI should be of some comfort to those suffering from the condition, as no link was found between the unusual symptoms and neurodegenerative diseases. changes

“Post-traumatic stress and mood-related symptoms are not surprising given the concerns of many participants,” he said.

Last year, U.S. intelligence agencies released their first report on the “Havana syndrome,” which concluded that the incidents that affected about 1,000 U.S. officials worldwide were unlikely to have been caused by attacks by a foreign power.

Most of the reported cases were related to “medical conditions or technical and environmental factors, including undiagnosed diseases. Many other incidents have been reported due to excessive caution,” he added.

“I don’t think there’s anything in our study that contradicts those things,” said Dr. Chen of the NIH.