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Original Investigation
July 23/30, 2019

Neuroimaging Findings in US Government Personnel With Possible Exposure to Directional Phenomena in Havana, Cuba

Author Affiliations
  • 1DiCIPHR (Diffusion and Connectomics in Precision Healthcare Research) Lab, Philadelphia, Pennsylvania
  • 2Department of Radiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia
  • 3Department of Neurosurgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia
  • 4Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia
  • 5Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia
  • 6Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Perelman School of Medicine, Philadelphia
  • 7Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania
  • 8Rehabilitation Medicine Service, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania
  • 9Center for Clinical Epidemiology and Biostatistics, Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Perelman School of Medicine, Philadelphia
  • 10Section for Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia
  • 11Department of Optometry, Salus University, Elkins Park, Pennsylvania
  • 12Good Shepherd Penn Partners, University of Pennsylvania, Philadelphia
  • 13Department of Molecular, Cellular, and Biomedical Sciences, CUNY School of Medicine, City College of New York, New York
  • 14Department of Psychiatry, University of Pennsylvania, Perelman School of Medicine, Philadelphia
  • 15Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia
JAMA. 2019;322(4):336-347. doi:10.1001/jama.2019.9269
Key Points

Question  Do advanced neuroimaging findings differ between US government personnel who experienced neurological signs and symptoms after potential exposure to directional phenomena in Havana, Cuba, and individuals not exposed to directional phenomena?

Findings  In this study comparing 40 US government personnel with 48 healthy controls, advanced brain magnetic resonance imaging techniques revealed significant between-group differences in whole brain white matter volume, regional gray and white matter volume, cerebellar tissue microstructural integrity, and functional connectivity in the auditory and visuospatial subnetworks but not in the executive control subnetwork.

Meaning  Neuroimaging findings differed between controls and US government personnel who experienced neurological signs and symptoms after potential directional phenomena exposure in Havana, Cuba, although the clinical relevance of these differences is uncertain and may require further study.

Abstract

Importance  United States government personnel experienced potential exposures to uncharacterized directional phenomena while serving in Havana, Cuba, from late 2016 through May 2018. The underlying neuroanatomical findings have not been described.

Objective  To examine potential differences in brain tissue volume, microstructure, and functional connectivity in government personnel compared with individuals not exposed to directional phenomena.

Design, Setting, and Participants  Forty government personnel (patients) who were potentially exposed and experienced neurological symptoms underwent evaluation at a US academic medical center from August 21, 2017, to June 8, 2018, including advanced structural and functional magnetic resonance imaging analytics. Findings were compared with imaging findings of 48 demographically similar healthy controls.

Exposures  Potential exposure to uncharacterized directional phenomena of unknown etiology, manifesting as pressure, vibration, or sound.

Main Outcomes and Measures  Potential imaging-based differences between patients and controls with regard to (1) white matter and gray matter total and regional brain volumes, (2) cerebellar tissue microstructure metrics (eg, mean diffusivity), and (3) functional connectivity in the visuospatial, auditory, and executive control subnetworks.

Results  Imaging studies were completed for 40 patients (mean age, 40.4 years; 23 [57.5%] men; imaging performed a median of 188 [range, 4-403] days after initial exposure) and 48 controls (mean age, 37.6 years; 33 [68.8%] men). Mean whole brain white matter volume was significantly smaller in patients compared with controls (patients: 542.22 cm3; controls: 569.61 cm3; difference, −27.39 [95% CI, −37.93 to −16.84] cm3; P < .001), with no significant difference in the whole brain gray matter volume (patients: 698.55 cm3; controls: 691.83 cm3; difference, 6.72 [95% CI, −4.83 to 18.27] cm3; P = .25). Among patients compared with controls, there were significantly greater ventral diencephalon and cerebellar gray matter volumes and significantly smaller frontal, occipital, and parietal lobe white matter volumes; significantly lower mean diffusivity in the inferior vermis of the cerebellum (patients: 7.71 × 10−4 mm2/s; controls: 8.98 × 10−4 mm2/s; difference, −1.27 × 10−4 [95% CI, −1.93 × 10−4 to −6.17 × 10−5] mm2/s; P < .001); and significantly lower mean functional connectivity in the auditory subnetwork (patients: 0.45; controls: 0.61; difference, −0.16 [95% CI, −0.26 to −0.05]; P = .003) and visuospatial subnetwork (patients: 0.30; controls: 0.40; difference, −0.10 [95% CI, −0.16 to −0.04]; P = .002) but not in the executive control subnetwork (patients: 0.24; controls: 0.25; difference: −0.016 [95% CI, −0.04 to 0.01]; P = .23).

Conclusions and Relevance  Among US government personnel in Havana, Cuba, with potential exposure to directional phenomena, compared with healthy controls, advanced brain magnetic resonance imaging revealed significant differences in whole brain white matter volume, regional gray and white matter volumes, cerebellar tissue microstructural integrity, and functional connectivity in the auditory and visuospatial subnetworks but not in the executive control subnetwork. The clinical importance of these differences is uncertain and may require further study.

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