A case series published by JAMA this week is shedding light on the medical mystery of U.S. government personnel working on assignment in Havana, Cuba, who have reported neurological symptoms they associated with very loud sounds and air pressure changes.
Physicians and other specialists at the University of Pennsylvania’s Center for Brain and Injury Repair examined 21 of the 24 workers identified by the State Department as being injured. They did so about 200 days after the workers reported being exposed to high-volume buzzing and grinding-type noises and vibrations similar to the way air rolls into a moving car with the windows partially rolled down.
Objective findings of cognitive, vestibular (balance) and oculomotor (eye movement) abnormalities were found in the vast majority of the patients. Most of the patients also self-reported headaches, trouble sleeping and visual and auditory problems.
A panel convened by the U.S. State Department said last July that the symptoms most likely were related to neurotrauma from a non-natural source. By contrast, the Cuban government maintained in a state-run TV broadcast aired in December that the noises behind the trouble were merely cicadas or crickets.
“The clinical manifestations may represent a novel clinical entity, which appears to have resulted from a widespread brain network dysfunction ... as seen in mild traumatic brain injury, or concussion, as well as injury to the peripheral vestibular system in some cases,” the study said. “It is currently unclear if or how the noise is related to the reported symptoms.”
“Unifying explanation” elusive
In a JAMA news article, study co-author and brain-injury rehabilitation specialist Randel Swanson, DO, PhD, was quoted as saying the government workers’ symptoms were very similar to those of patients who “had a traumatic brain injury from being in a car accident or a blast in the military.”
“It’s like a concussion without a concussion,” Dr. Swanson added.
Both the study’s authors and the authors of an accompanying JAMA editorial noted the inherent limitations of a case series and urged caution in interpreting the findings. The two neurologists who co-wrote the editorial concluded, despite that caveat, “the similarities among the 21 cases merit consideration of a common medical, environmental or psychological event as the potential cause.”
They added that “a unifying explanation for the symptoms experienced by the U.S. government officials described in this case series remains elusive and the effect of possible exposure to audible phenomena is unclear.”
The editorialists, JAMA Associate Editor Christopher C. Muth, MD, and Steven L. Lewis, MD, of the Lehigh Valley Health Network in Allentown, Pennsylvania, said further testing using advanced neuroimaging techniques could help “characterize any functional or structural brain changes.”
They also recommended that government employees traveling to work in Cuba “undergo baseline testing prior to deployment to allow for a more informed interpretation of abnormalities that might later be detected after a potential exposure.”