New studies by the National Institutes of Health failed to find evidence of brain injury in scans or blood markers of the diplomats and spies who suffered symptoms of Havana syndrome, bolstering the conclusions of U.S. intelligence agencies about the strange health incidents.
Spy agencies have concluded that the debilitating symptoms associated with Havana syndrome, including dizziness and migraines, are not the work of a hostile foreign power. They have not identified a weapon or device that caused the injuries, and intelligence analysts now believe the symptoms are most likely explained by environmental factors, existing medical conditions or stress.
The lead scientist on one of the two new studies said that while the study was not designed to find a cause, the findings were consistent with those determinations.
The authors said the studies are at odds with findings from researchers at the University of Pennsylvania, who found differences in brain scans of people with Havana syndrome symptoms and a control group
Dr. David Relman, a prominent scientist who has had access to the classified files involving the cases and representatives of people suffering from Havana syndrome, said the new studies were flawed. Many brain injuries are difficult to detect with scans or blood markers, he said. He added that the findings do not dispute that an external force, like a directed energy device, could have injured the current and former government workers.
The studies were published in The Journal of the American Medical Association on Monday alongside an editorial by Dr. Relman that was critical of the findings.