SARAH MCCAMMON, HOST:
It was the middle of a Moscow winter about four years ago when Marc Polymeropoulos was asleep in his hotel room until suddenly...
MARC POLYMEROPOULOS: I was awoken, you know, in the middle of the night. But I had just had incredible vertigo, dizziness. I wanted to throw up.
MCCAMMON: That's Polymeropoulos speaking with NPR last October. He was on CIA business in Russia, where he had just become the No. 2 official for clandestine operations in Europe.
POLYMEROPOULOS: I started this kind of incredible journey of seeing, you know, multiple doctors, multiple MRIs and CT scans and X-rays.
MCCAMMON: Doctors were not able to diagnose a root cause of his illness. Polymeropoulos isn't alone.
(SOUNDBITE OF MONTAGE)
UNIDENTIFIED REPORTER #1: American diplomats stricken with the mysterious and unexplained condition are now speaking out.
UNIDENTIFIED REPORTER #2: Two hundred Americans have now come forward to report possible symptoms of the mysterious illness called Havana syndrome.
UNIDENTIFIED REPORTER #3: A possible Havana syndrome incident may be the reason Vice President Kamala Harris' trip from Singapore to Vietnam was delayed for several hours.
MCCAMMON: Many U.S. officials and their families have reported similar symptoms that are known as Havana syndrome because the U.S. government first publicly acknowledged cases reported by U.S. diplomats and intelligence officials in Havana, Cuba. But cases have been reported in India, Austria and, just this week, at the Colombian Embassy in Bogota. Lawyer Mark Zaid has represented Polymeropoulos and several other former U.S. intelligence officials who've suffered such brain injuries. He says many of his clients feel the U.S. government wasn't taking their concerns seriously enough.
MARK ZAID: I have my concerns that the U.S. government is not doing everything that it needs to be doing to identify these cases both past and present in order to stop it from happening in the future.
MCCAMMON: He's been helping them seek recourse.
ZAID: We're looking for answers. The key thing first is we want to ensure timely and proper medical treatment, and then we want answers. We're tired of the subterfuge of the U.S. government hiding this information.
MCCAMMON: But now the U.S. government is taking steps to deal with this mysterious illness. Last year the U.S. State Department commissioned a report by the National Academy of Sciences, and this summer CIA Director Bill Burns told NPR helping victims and finding out what's causing this illness is at the top of his list.
BILL BURNS: And we are determined to get to the bottom of this.
MCCAMMON: And last week President Biden signed the Havana Act, which provides financial support to diplomats and other federal officials who've suffered brain injuries on the job. Mark Zaid, the lawyer, says the Biden administration's approach to addressing his client's mysterious brain injuries is encouraging.
ZAID: We will ultimately learn much more about it. I just don't know whether it will be in the next year or five years or 10 years, but it will happen.
MCCAMMON: Exactly how these brain injuries are happening is still a big unanswered question, a question a researcher working on that National Academy of Sciences report tried to answer.
DAVID RELMAN: To us, this was a very perplexing, very unusual syndrome with features that many of us had really heard nothing about before.
MCCAMMON: That's Stanford medical researcher David Relman. He headed the National Academy of Sciences' investigation into the so-called Havana syndrome. The State Department had asked them to look at three areas - the nature of the illness, the, quote, "mechanisms" that might explain how it happened and how it could be treated. The group reviewed a number of studies, reports and spoke to some of the patients themselves.
RELMAN: We spoke to about eight individuals, most of them having served in Havana but several from China. And we found that to be incredibly insightful for us.
MCCAMMON: What did you hear from them directly?
RELMAN: We heard about how the case began, how their experience occurred. And some of them told us some very dramatic stories about crawling out of the room and finding that everything resolved and in some cases then returning to find that everything resumed again back at the exact same spot. So it was this dramatic sense that everything was taking place at a particular spot. That something, for us, could not be explained by natural phenomenon that we had heard about.
MCCAMMON: And for those who haven't read your report, what is your team's best guess about what's going on here?
RELMAN: So we deliberately chose to focus on just a handful of mechanisms that had been suggested to us by work that had been published already or by suggestions from our sponsors. These included microwave radiation, chemicals in particular pesticides, infectious agents that might have been common in Cuba, which is where many of the cases that we looked at had taken place, and then finally psychosocial mechanisms. And the mechanism that we found most plausible was a form of microwave radiation that occurs in a pulsed or intermittent form.
MCCAMMON: Yeah, explain more. How would that cause these symptoms?
RELMAN: Well, there's still a lot of missing information and lack of molecular understanding of how this might occur. But we looked at a variety of reports in the open source literature. We looked at a number of studies that have been done looking at small animals that have been subjected to microwave radiation as well as cells in isolation. And we found circumstantial evidence that suggested that this form of microwave radiation in pulsed form might set up a certain form of pressure wave within the head that would then reverberate and cause damage to cells and pathways where normal neurotransmitters are communicating. And we believe, although we can't show with direct evidence, that this phenomenon could account for at least some of the clinical features that we heard about and read about.
MCCAMMON: And, Dr. Relman, we should note that the State Department still considers your team's conclusions from the report to be a hypothesis. How confident are you that microwaves are what's behind these symptoms?
RELMAN: We were not confident. And I have to be clear. We view this as plausible, but, again, we didn't have any direct evidence that this could explain the entire story for sure or even parts of it.
MCCAMMON: Would victims have to be intentionally targeted, intentionally hit with these microwaves?
RELMAN: We thought about what the various sources of such pulsed microwave energy might be. And, again, we were not familiar with or read into the exact circumstances of these cases, so we couldn't comment on the situational information that might have either supported or refuted this idea. But when we look at the world around us, we know there's plenty of microwave radiation. However, most of it comes in the form of a continuous wave - things like microwave ovens or cellphones. But we could not come up with an easy scenario in which these natural but less common pulsed forms of microwave radiation might have explained these cases. And that left us with this very sort of disconcerting notion that it had been produced deliberately by other actors whose purposes we really weren't in a position to fathom.
MCCAMMON: Before this syndrome - Havana syndrome was reported, how much was known in the medical community about these kinds of symptoms potentially being linked to microwaves?
RELMAN: Relatively little. As I say, we were able to find some literature. But, again, there just isn't a lot of reported literature in humans. But, you know, the bottom line is that this is still a perplexing story that still needs further investigation.
MCCAMMON: That's David Relman, the Stanford professor of medicine who led the U.S. government-commissioned report investigating the so-called Havana syndrome. Transcript provided by NPR, Copyright NPR.