U.S. government employees with mysterious 'Havana syndrome' show no brain damage
The authors of two studies conducted under the auspices of the U.S. government's National Institutes of Health failed to find any significant differences between U.S. government employees who reported having Havana syndrome, their family members and a control group. The causes of the "abnormal health incidents" still remain unclear.
Experts have been trying for more than seven years to unravel the mystery of the so-called Havana syndrome experienced by U.S. intelligence officers, civil servants, diplomats and their families abroad. The first and most famous cases occurred in Cuba, in its capital Havana, in 2016-2017. Subsequently, they were repeated in China, Austria, Africa, Tajikistan and Russia. In total, according to the CIA, several hundred people were affected by the obscure ailment. Cuban authorities denied involvement, as did Russian authorities.
What is "Havana syndrome"
Patients complained of a wide range of symptoms: ringing in the ears, headaches, high blood pressure, nausea, painful sensations, general discomfort, disorientation, insomnia, anxiety, memory loss and other cognitive impairments. Some have claimed it was like being hit by a "blast wave." Sometimes the effects of the Havana Syndrome passed quickly; in other cases, victims required long-term care, complained of having to take early retirement and spent a lot of money on medical treatment.
Various experts and politicians have repeatedly insisted that the causes of the "Havana syndrome" may be the use of "secret weapons" and "targeted attacks" by countries unfriendly to America, but this version, after years of investigation, has not been confirmed by the U.S. intelligence agencies themselves.
What the authors of the new research have found out
The first brain scans of Americans who survived, "abnormal health incident", showed tissue damage usually seen in people with concussions after an explosion or car accident. Researchers at the University of Pennsylvania, who conducted their own study in 2019, found significant differences in "Havana syndrome" survivors and controls in white matter volume, cerebellar tissue integrity, and functional connectivity of neurons.
Now two teams of medical professionals, including military, neurologists, rehabilitation specialists and ophthalmologists from the U.S. National Institutes of Health, have double-checked the previous findings. They published their findings in two papers for the journal JAMA Network.
The first study, which was conducted at the MRI Clinical and Research Center in Maryland from June 2018 to November 2022, included 81 participants with "abnormal health incidents" (AHIs) and 48 controls who had generally similar experiences in the civil service: the average age was about 42-43 years old, and nearly half were women. The subjects underwent various types of magnetic resonance imaging of the brain an average of 80 days after the onset of symptoms. In half of the cases, additional examinations were performed about 6 to 12 months after the first one.
The clinicians identified several neuroimaging measures to assess group differences between participants with AIH and members of the control group.
After adjusting for all indicators, the scientists were still unable to find statistically significant differences between Havana Syndrome victims and control group participants. Among other things, there was no difference in the volume of gray and white matter of the central nervous system, as well as in the functional connections of neurons. Therefore, the authors of the first paper concluded that there was no evidence of widespread brain lesions in patients who reported "abnormal health incidents."
The second study included not only U.S. government officials with Havana Syndrome, but also their relatives. The sample included 86 government officials who had worked in Cuba, Austria, China and other countries, their adult family members with the same "abnormal health incidents" and 30 United States government employees who served as a control group (12 of whom had been to Cuba). The average age was 42-43 years, with women and men still about equally represented.
Volunteers underwent clinical assessments of hearing, vision, balance, oculomotor, cognitive, vestibular function, and blood biomarkers. In addition, participants reported whether they had signs of AIH such as fatigue, PTSD, depression, pain, and impaired quality of life.
Headache proved to be the most frequent symptom of Havana Syndrome (74%), followed by: cognitive impairment (69%), sleep problems (59%), tinnitus or ringing in the ears (56%), balance problems (52%), dizziness (37%) and visual changes (37%). Patients identified migraine as the most common type of headache (36%). Physical and neurologic examination findings were mostly normal, with occasional signs of balance and gait disturbances - predominantly in people with APPG. Three patients with AIH were found to have cancer during the studies, and 24 (28%) had a functional neurological disorder.
No particular hearing, vision or vestibular problems were found in people with or without Havana syndrome. Blood test results were also generally the same. The only point: patients with AIH scored worse on a balance questionnaire, and their functional gait scores were worse than those of the control group. This, as the study authors emphasized, was certainly influenced by the presence of PPPG, which is considered a brain dysfunction, a common form of functional vertigo and usually results from temporary vestibular disturbances. Moreover, balance test results do not necessarily mean damage to the central nervous system, the medics added.