Ten years ago U.S. officials stationed in Cuba started reporting a strange collection of symptoms, from ringing ears and dizziness to crushing headaches and memory loss. The symptoms, collectively dubbed “Havana syndrome” and more formally known as anomalous health incidents (AHIs), suggested a neurological issue. But what, exactly, the root cause was has remained a matter of intense debate among both medical and military experts.
Now, according to CNN, the U.S. Department of Defense has reportedly been testing a machine that is believed to produce pulsed radio waves and may be linked to Havana syndrome. The DOD and the Department of Homeland Security did not immediately respond to a request for comment.
A device that could produce powerful pulsed radio waves is among the many speculated but unproven causes of Havana syndrome, which also include possible exposure to neurotoxins and mass psychogenic illness (collective anxiety).
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Medical experts continue to debate even the specific neurological consequences of Havana syndrome: researchers at the National Institutes of Health and their colleagues performed magnetic resonance imaging (MRI) scans on 81 federal workers and their family members who said that they had heard a noise and felt pressure in their head and then developed headaches and other cognitive symptoms. The results, published in 2024 in JAMA, showed no differences between the brains of these individuals and those of a control group. Other studies have also found inconclusive results.
“It is possible that individuals with an [anomalous health incident] may be experiencing the results of an event that led to their symptoms, but the injury did not produce the long-term neuroimaging changes that are typically observed after severe trauma or stroke. We hope these results will alleviate concerns about AHI being associated with severe neurodegenerative changes in the brain,” said Carlo Pierpaoli, lead author of the NIH study, in a statement at the time.