Since late 2016, some U.S. diplomats, now numbering 24, have suffered various medical problems while stationed in Cuba. Perplexingly investigations by the FBI and other U.S. agencies as well as Cuban investigators over nearly the last 16 months have failed to ascertain the cause or the culprit, if any, of the cause of their problems. On February 14 a new medical report was released on these individuals.
The Medical Report [2[
U.S. physicians at the University of Pennsylvania’s Perelman School of Medicine in an article in the Journal of the American Medical Association (JAMA) have published the preliminary results of their examination of 21 of these 24 individuals. Here are the key findings of their report:
- The patients “appeared to have sustained injury to widespread brain networks.”
- The patients have experienced “persisting disability of a significant nature” involving “hearing, vision, balance and brain symptoms similar to the brain dysfunction seen with concussions, but without histories of head trauma.”
- In most cases, the affected diplomats reported hearing a loud, painful noise that they later associated with their symptoms, but the physicians concluded, “There is no known mechanism for audible sound to injure the brain” and “it is currently unclear if or how the noise is related to the reported symptoms.”
- “Viruses or chemical exposures are unlikely,” but could not be “systematically excluded.”
- “Advanced MRI scans spotted a few changes in some patients in what are called white matter tracts,” but these might be attributed to previous events.
- “Several of the objective manifestations consistently found in this cohort,” including vision and balance abnormalities, “could not have been consciously or unconsciously manipulated.”
The study’s lead author, Dr. Douglas H. Smith, director of the Center for Brain Injury and Repair at the University of Pennsylvania, said, “This is a preliminary report.We thought it was important to get it out from a public health standpoint.” Nevertheless, “Uniformly, everyone who saw these patients was absolutely convinced. It looked like concussion pathology. Processing speed, inability to remember — those are such classic symptoms we see in concussion. We all believe this is a real syndrome.This is concussion without blunt head trauma.”
JAMA Editorial About the Report 
An accompanying JAMA editorial by Drs. Christopher C.Muth and Steven L. Lewis emphasized caution in interpreting the data of this report. It stated, “although the patients were united to some extent by the common locations in which their symptoms first developed, there was some variability between patients in terms of the symptoms that each experienced. The precise time course over which each individual’s symptoms evolved was not provided. Given that evaluations were conducted a mean of 203 days after onset, it remains unclear whether individuals who developed symptoms later were aware of the previous reports of others. Furthermore, the quantitative results for specific tests (eg, neuropsychological tests) are not yet available for all affected patients, so independent assessment as to the scope and severity of deficits among all individuals remains challenging.”
This JAMA editorial also listed several limitations in this case study that “should also urge caution in interpreting the findings.” It concluded, “Before reaching any definitive conclusions, additional evidence must be obtained and rigorously and objectively evaluated.”
Another Reaction to the Report 
Another medical expert offered comments. C. Edward Dixon, a professor of neurological surgery at the University of Pittsburgh, who was not involved in the research, said, “The study was conducted by the top concussion research team in the world utilizing state-of-the-art methods” and the findings suggest “a significant brain insult.”
 The problems of these diplomats have been discussed in previous posts listed in the “ U.S. Diplomats Medical Problems in Cuba, 2016-2018” section of List of Posts to dwkcommentaries—Topical: CUBA.
 Drs. Swanson, Hampton, McKenzie, et al., Neurological Manifestations Among U.S. Government Personnel Regarding Directional Audible and Sensory Phenomena in Havana Cuba, JAMA (Feb. 15, 2018); Assoc. Press, Report Details Harm to Cuba Diplomats, but Offers No Cause, N.Y. Times (Feb. 14, 2018); DeYoung, Doctors find neurological damage to Americans who served in Cuba, Wash. Post (Feb. 14, 2018).
 Drs. Muth & Lewis, Editorial: Neurological Symptoms Among U.S. Diplomats in Cuba, JAMA (feb. 15, 2018).
 Kolata, Diplomats in Cuba Suffered Brain Injuries. Experts Still Don’t Know Why, N.Y. Times (Feb. 15, 2018).