Two University of Pennsylvania researchers who examined diplomatic personnel from the U.S. Embassy in Havana confirm they suffered brain injuries, but said the cases weren’t accompanied by head trauma as would have been expected.
There are still no indications of what may have caused the diplomats’ mysterious symptoms. The report, published Wednesday in The Journal of American Medical Association, said the unique circumstances of the patients “raise concern about a new mechanism for possible acquired brain injury from an exposure of unknown origin.”
In an editorial, JAMA said an explanation “remains elusive” and “many potential causes for the symptoms.... remain possibilities. Before reaching any definitive conclusions, additional evidence must be obtained and rigorously and objectively evaluated.”
Initial clinical evaluations of 80 diplomats and family members at the University of Miami showed that some of the diplomats had symptoms resembling concussions, but none of them reported having suffered head trauma. Because of this, 21 of 24 confirmed cases were referred to the University of Pennsylvania Department of Neurosurgery and Center for Brain Injury and Repair.
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In contrast to classic concussions, most of the Havana patients “exhibited significant impairment that persisted for months with no significant improvement in multiple cases until rehabilitation was initiated,” according to the JAMA paper.
In late 2016, diplomats at the U.S. Embassy first began noticing health symptoms that they associated with mysterious sounds heard in their homes. Later, diplomats reported similar incidents at two Cuban hotels. Some diplomats described a directional beam of sound. Among the words used to describe it were “buzzing, grinding metal, piercing squeals and humming.”
The main authors of the paper, Dr. Douglas H. Smith and Dr. Randy Swanson, said that “it is currently unclear if or how the noise is related to the reported symptoms.”
“Affected individuals described the sounds as directional, intensely loud, and of pure and sustained tonality. Sixteen of the patients said they heard a high-pitched sound, while two indicated they heard a low-pitched sound. Some didn’t hear any sounds and a pressure-like sensation was reported by two of the three patients who didn’t hear a sound.”
The sounds appeared to be directional, the JAMA paper said. Fifty-seven percent of the patients reported that after they changed locations, the strange sensations disappeared.
While the U.S. government has never blamed Cuba for being behind what it calls “attacks,” it has held the Cuba government responsible for not protecting American diplomats while they were on Cuban soil. In September, it withdrew about two-thirds of the embassy staff and it has expelled 17 diplomats from the Cuban Embassy in Washington.
Cuba is also conducting its own investigation, but has complained that the U.S. government has shared so little information about patients that it is having trouble reaching any conclusions.
The diplomats all reported suffering some combination of symptoms, including sharp ear pain, ringing in one ear, nausea, extreme fatigue, disorientation, headaches, vertigo, and trouble focusing within hours or days of exposure. Most of those symptoms quickly resolved.
But other serious problems, including difficulties with memory and concentration, recurrent headache, hearing loss, difficulty in walking, and sleep disturbances persisted for a longer period of time.
“From days to weeks after exposure, individuals reported that they experience the onset of additional symptoms. For at least six individuals, supervisors and colleagues noted “a clear change in work performance,” the paper said.
The JAMA paper gives the first indication of how many patients suffered from various symptoms.
Three of them showed moderate to severe hearing loss. More common were persistent balance, cognitive, visual and auditory dysfunction, sleep impairment and headaches, which variously affected about 15 percent to nearly 19 percent of the patients.
Of the 21 patients evaluated and treated at the University of Pennsylvania, 11 were women and 10 men.
Follow Mimi Whitefield on Twitter: @HeraldMimi