Washington, D.C. – Two recent studies on the enigmatic ‘Havana syndrome’ have failed to identify a physical cause but have indicated a potential connection to mental health. Since 2016, over 1,000 US government personnel stationed worldwide have reported experiencing symptoms including hearing intrusive sounds, pressure on their heads, severe headaches, dizziness, and cognitive dysfunction.
The condition first gained media attention when federal employees stationed in Havana, Cuba, reported these anomalous health incidents (AHIs), leading to the adoption of the term ‘Havana syndrome’. However, researchers led by the National Institutes of Health (NIH) have found no significant differences in brain scans or other biological tests between individuals with Havana syndrome and healthy controls.
Despite the lack of a clear biological explanation for the symptoms, the findings do highlight the need to consider multiple factors when interpreting the results. NIH neuroscientist Carlo Pierpaoli, the first author of one of the studies, emphasized that while there may not be detectable brain injuries apparent in MRI scans, it is still possible that an adverse event impacting the brain occurred at the time of the AHI.
In one study, researchers examined MRI scans of 81 participants who reported AHIs and compared them with 48 healthy controls, 29 of whom had similar job assignments but no reported AHIs. Another study involved 86 participants with AHIs and 30 controls with similar job assignments who underwent various tests including blood biomarker testing, auditory and visual assessments, and neuropsychological evaluations.
By analyzing a variety of observable traits, the research team aimed to identify structural brain or biological differences in individuals with AHIs. While the studies did not find consistent imaging abnormalities differentiating those with AHIs from healthy controls, they did discover that individuals with Havana syndrome reported more balance problems and higher levels of fatigue, depression, and post-traumatic stress disorder compared to the control group.
Furthermore, 41 percent of AHI-affected participants met the criteria for functional neurological disorders (FNDs), conditions that can result from abnormal brain function and are often associated with stress, depression, and anxiety. The researchers suggest that current tests and sample sizes may not be capable of detecting the external factors that could have triggered the symptoms of Havana syndrome.
In conclusion, although the studies did not uncover significant differences in participants with AHIs, the researchers stress the importance of acknowledging the realness of the symptoms and the significant disruptions they cause in the lives of those affected. The findings, published in JAMA, underscore the complex nature of Havana syndrome and the challenges in diagnosing and treating this mysterious condition.