Brain Scans Find Differences But No Injury In U.S. Diplomats Who Fell Ill In Cuba

Jul 23, 2019
Originally published on July 23, 2019 10:05 pm

A close look at the brains of 40 U.S. Embassy workers in Cuba who developed mysterious symptoms has found no evidence of injury. The State Department has said the employees were hurt by some sort of attack.

Advanced brain imaging techniques did reveal some subtle differences in the workers' brains, says Ragini Verma, a professor of radiology at the University of Pennsylvania and an author of the study published in this week's JAMA, the journal of the American Medical Association.

But those differences "do not reflect the imaging differences that we see in [traumatic brain injury] or concussion," Verma says.

"All you can say is something happened, which caused their brain to change," she says.

And even that conclusion was challenged by brain scientists who have been skeptical that any diplomat was attacked or injured from what became known as "Havana syndrome."

The differences could have been random or simply the result of different life experiences that can change the brain — like learning a foreign language, says Sergio Della Sala, a professor of human cognitive neuroscience at the University of Edinburgh in the U.K. He called the study in JAMA "half-baked."

"There is no evidence of any pathology," says Douglas Fields, a neuroscientist who has investigated and written about the events in Cuba. "And when you look at the data, there's no coherent syndrome, no pattern."

The new results should end speculation that embassy workers were injured by a sonic weapon or something even more exotic, Fields says.

"The physical evidence to support the idea that there was some sort of an energy beam is completely lacking," he says.

The study is the latest development in a mystery that began in 2016, when dozens of people associated with the U.S. Embassy in Havana began reporting strange, high-pitched sounds or sudden changes in air pressure. Shortly after these events, they began experiencing dizziness, headaches, sleep problems, hearing problems and foggy thinking.

The State Department began referring those workers to the University of Pennsylvania's Center for Brain Injury and Repair.

In 2018, doctors there reported in JAMA that 21 workers had symptoms that resembled those of a traumatic brain injury or concussion.

As part of their evaluation, people sent to the University of Pennsylvania also got MRI brain scans, which appeared normal.

"Just a traditional read of the images did not reveal much," Verma says.

Verma and several colleagues decided to take another look using advanced imaging techniques usually reserved for scientific research.

They studied brain scans from 40 government workers who had reported symptoms. Then they compared those images with brain images from groups of healthy people.

This time, the team did find something.

"The most important thing is that there were differences," Verma says.

The differences were subtle and involved measures of brain volume, brain networks and the fibers that carry signals around the brain. They were most apparent in an area called the cerebellum, which is involved in balance and movement, and were also found in areas of the brain that process sound.

Differences in those areas, Verma says, might help explain why the workers reported symptoms involving balance and hearing.

But Fields says even that is a reach.

"First of all, these techniques are not diagnostic, they are descriptive," he says. "And they don't provide any clinical evidence of any kind of abnormality or pathology. What they show are minor differences between two groups."

And the existence of some differences is hardly surprising, he says.

"These methods are used to find differences that are associated with being left-handed or right-handed, male or female, low IQ [or] high IQ, whether you are a musician or not," he says. "They're all within the normal range."

And 12 of the workers had a history of concussion, which also could account for some of the differences.

The real importance of the study is in what it did not find, Fields says.

"If there'd been brain injury, that would have been evident on the clinical brain imaging studies that were done before," he says. "There was no evidence of any pathology, and these more sophisticated measures confirm that."

The State Department did not respond to requests for comment on the study.

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ARI SHAPIRO, HOST:

An update on the U.S. government workers who had health problems while in Cuba. The State Department says they sustained brain injuries from some sort of attack. Several prominent brain scientists have challenged that conclusion. And now, as NPR's Jon Hamilton reports, a new study appears to back those scientists.

JON HAMILTON, BYLINE: In 2016, dozens of people associated with the embassy in Havana began hearing a high-pitched noise or feeling a wave of pressure. Then they experienced dizziness, headaches, sleep problems and foggy thinking. The workers were sent to the University of Pennsylvania's Center for Brain Injury and Repair. They got MRI scans. And Ragini Verma, a professor of radiology, says the scans looked normal.

RAGINI VERMA: Just a traditional read of the images did not reveal much.

HAMILTON: So Verma and a team decided to use advanced imaging techniques usually reserved for scientific research. The team studied 40 government workers who'd reported symptoms of what's become known as Havana syndrome. Then they compared these images with images from groups of healthy people. Verma says this time, the team did find something.

VERMA: The most important thing is that there were group differences.

HAMILTON: Subtle differences in brain volume, brain networks and in the structure of brain tissue. The structural differences were most apparent in the cerebellum, an area involved in balance and movement. But Verma says there was no evidence of traumatic brain injury.

VERMA: All the imaging differences that we see do not reflect the imaging differences that we see in TBI or concussion.

HAMILTON: And Verma says it's hard to know what the differences mean.

VERMA: All you can say is something happened, which caused their brain to change. And those are reflected in their clinical symptoms and their imaging results.

HAMILTON: Of course, what everybody has been asking about is is there evidence that these people were attacked or not? Does this study answer that question?

VERMA: No.

HAMILTON: The study appears in JAMA along with an editor's note saying its clinical relevance is uncertain. Doug Fields, a neuroscientist who has investigated the events in Cuba, says that's an understatement.

R DOUGLAS FIELDS: First of all, these techniques are not diagnostic. They're descriptive, and they don't provide any clinical evidence of any kind of abnormality or pathology. What they show are minor differences between two groups.

HAMILTON: And Fields says group differences are pretty common.

FIELDS: These methods are used to find differences that are associated with being left-handed or right-handed or male or female, high IQ, low IQ, whether you're a musician or not. But they're all within normal range.

HAMILTON: Fields says the significance of the study is in what it did not find.

FIELDS: If there'd been brain injury, that would have been evident on the clinical brain imaging studies that were done before. And there was no evidence of any pathology. And these more sophisticated measures confirm that.

HAMILTON: Fields says the new results should end speculation that embassy workers were injured by a sonic weapon or something even more exotic.

FIELDS: The physical evidence to support the idea that there was some sort of a energy beam is completely lacking.

HAMILTON: The State Department did not respond to requests for comment.

Jon Hamilton, NPR News. Transcript provided by NPR, Copyright NPR.