Advanced Neuroimaging Findings in US Government Personnel With Possible Directional Phenomenon Exposure in Havana, Cuba

In a previous issue of JAMA, Swanson et al¹ described the neurological signs and symptoms experienced by 21 US government personnel with possible exposure to directional audible and sensory phenomena in Havana, Cuba, beginning in late 2016. Many of the individuals reported that they experienced sleep disturbances, visual and auditory symptoms, cognitive difficulties, headache, and balance problems that required rehabilitative therapies. The initial report indicated that brain magnetic resonance imaging (MRI) revealed evidence of nonspecific white matter hyperintensities in some of the individuals, but it was uncertain whether these findings were clinically relevant or related to the potential exposure.

In this issue of JAMA, Verma et al² report the results of advanced neuroimaging analyses among 40 US government employees with similar possible exposure from late 2016 to May 2018 (including 20 of the 21 individuals included in the previous report). The imaging findings from these individuals were compared with imaging from a group of demographically similar controls. When analyzed at the group level, differences were observed in regional brain volumes (including areas of both gray and white matter in the cerebrum and cerebellum) and in measures of tissue microstructural integrity. Additionally, functional MRI demonstrated decreased functional connectivity in the auditory and visuospatial subnetworks of the US government personnel compared with controls.

These unique data provide additional information and contribute to a growing evidence base that may help in understanding the neurological signs and symptoms experienced by this group of individuals. However, despite the differences in advanced neuroimaging metrics between patients and controls reported in this study, the clinical relevance of these differences is uncertain, and the exact nature of any potential exposure and the underlying etiology of the patients’ symptoms still remain unclear. The best way to continue to evaluate these patients is with thorough and objective consideration of rigorously collected scientific evidence.

Corresponding Author: Christopher C. Muth, MD, JAMA, 330 N Wabash Ave, Chicago, IL 60611 (christopher.muth@jamanetwork.org).

Conflict of Interest Disclosures: None reported.