Two new federal studies found no significant evidence of brain injury among more than 80 patients with ''Havana syndrome," The Washington Post reported March 18.
For the studies, published March 18 in JAMA, researchers with the National Institutes of Health conducted extensive testing on 86 federal employees and family members who've experienced what the government has called "anomalous health incidents." Patients were assessed between June 2018 and November 2021 at the NIH Clinical Center in Bethesda, Md.
Researchers found no significant differences between participants with Havana syndrome symptoms and control participants in terms of auditory, vestibular, cognitive or visual function. MRI scans also showed no signs of brain injury. Researchers said the findings are positive but don't discount many patients' debilitating symptoms.
"These symptoms are real, and they feel it, and we acknowledge it," lead author Leighton Chan, MD, chief of rehabilitation medicine at NIH Clinical Center, told the Post.
About 200 U.S. diplomats and intelligence officers have reported symptoms potentially linked to Havana syndrome since the mysterious illness was first identified in 2016. People believed to have the condition report hearing a loud sound and pressure in their heads before experiencing dizziness, unsteady gait and visual disturbances, according to a 2020 report from the National Academies of Sciences.
Last March, a U.S. intelligence report determined the cases were not caused by actions of a foreign adversary, contradicting a long-standing theory that an enemy was using pulsed radio frequency energy to secretly target U.S. diplomats and intelligence officers.