New Brain Scans Add to Controversy Over Reported Illness at U.S Embassy in Cuba

By Gene Emery

July 24, 2019

(Reuters Health) - Advanced brain scans of U.S. Embassy employees who reported feeling ill while serving in Havana show the workers don't have the same amount of white matter and have different patterns of neural connections than a comparison group of people who did not work in Cuba, researchers at the University of Pennsylvania reported Tuesday.

The findings, published in the Journal of the American Medical Association, may be another clue confirming what the Trump administration characterized as a "sonic attack" on the workers, or it may be a red herring in a case that has prompted skeptics to question whether there was any kind of mysterious attack at all.

In 40 embassy personnel, the Penn team found 4.8% less white matter in the brain, 9% more gray matter in a key part of the brain, and other differences they judged to be significant. The comparison group consisted of 48 demographically similar healthy controls.

"It's pretty jaw-dropping," chief author Dr. Ragini Verma, a professor of radiology at Penn, told Reuters Health in a telephone interview.

In the JAMA paper, she and her colleagues conclude it's not clear if the brain patterns directly translate into meaningful health problems. Initial MRI scans of 21 workers had revealed no abnormalities.

Critics have said the complaints of the Havana workers vary widely, suggesting there is no such thing as a "Havana syndrome."

"Finding evidence of brain change doesn't provide evidence of brain injury or damage," said Dr. Jon Stone, a professor of neurology at the Centre for Clinical Brain Sciences at the University of Edinburgh, who was not involved in the study.

But Dr. Verma, who heads the Diffusion and Connectomics in Precision Healthcare Research imaging lab at Penn, said, "Most of these patients had a particular type of symptoms and there is a clinical abnormality that is being reflected in an imaging anomaly."

President Trump has said Cuba was responsible for what the U.S. State Department called "significant injuries" suffered by the workers beginning in 2016. The U.S. subsequently removed most of its embassy staff and told U.S. citizens not to travel to Cuba; it then tightened restrictions on travel to the island.

Canada has also removed personnel from Cuba because of similar complaints. Canada has long had good relations with Cuba.

Workers have complained of various problems such as headache, ringing in the ears, sleep disturbances, trouble thinking, memory problems, dizziness and balance problems.

The Penn team, in an earlier JAMA report, said the injury experienced by the 21 diplomats it examined was like a concussion, but with no blow to the head.

Since then, skeptics have challenged the State Department assertion that some unknown weapon attacked the workers.

For example, the odd sound that supposedly caused the problems was later identified as the mating call of the male Indies short-tailed cricket, which is notorious for its loudness.

For many reasons, the new study is "half baked," said Dr. Sergio Della Sala, a professor of human cognitive neuroscience, also at the University of Edinburgh.

For instance, the new study reveals that 12 of the affected people had a history of concussion prior to going to Cuba, "yet all 12 were included in the analyses," Dr. Della Sala said in an email to Reuters Health. "In comparison, none of the controls declared previous brain injury; this in itself could cause statistical group differences."

When those 12 people were omitted, the differences in the brains of the remaining workers who reported symptoms persisted, said Dr. Verma. She said she did not know if they continued to be statistically significant because that calculation was not done.

"A whole range of conditions such as those causing chronic dizziness, migraine or even depression will tend to show changes in the brain in these types of studies in comparison to healthy controls, since all those conditions arise from the brain," Dr. Stone told Reuters Health in an email. "The study supports the validity of the patients' report of symptoms but doesn't answer the question of whether they have had a brain injury or whether the exposure they report is relevant."

Most studies of this nature try to use the largest control group possible; it's difficult to determine what is "normal" based on scans of just 48 control subjects.

The JAMA paper does not explain how the 48 were selected. Dr. Verma said they were recruited as part of a general effort to get volunteers for research purposes.

With the type of sophisticated MRI testing used in the study, "this type of imaging is very sensitive to differences in gender, IQ, whether you're bilingual or monolingual, and whether you're right handed or left handed," said Douglas Fields, a prominent neuroscientist who has investigated the cases.

"Even weight can influence the findings; thinner people tend to have more white matter," said Dr. Stone.

The new study "confirms previous scientific opinion that there were no traumatic brain injuries. It shows no abnormalities, just differences," differences akin to assessing the detailed facial features of two classrooms of students - if you average their features, the two groups will look different. But that doesn't make one group abnormal, Dr. Fields explained.

"The comparison has been set up in a way such that it was inevitable that there would be some differences found," said Dr. Stone.

Dr. Fields said the efforts to identify a mysterious syndrome is distracting the embassy personnel from finding a more prosaic cause for their health problems.

"This, to my mind, is tragic," he said. "It's causing them enormous distress, telling them they have had their brain damaged in some way by being the target of an unknown weapon that defies the laws of physics, penetrates walls, follows people around and causes brain injury, and then to have this go on for two and a half years."


JAMA 2019.