Neuroimaging findings in US government personnel and their family members involved in anomalous
← Research streamIn 81 participants reporting AHIs and 48 matched controls, there were no significant between-group differences in volumetric MRI, diffusion MRI metrics, or resting-state functional connectivity after adjustment for multiple comparisons. Some differences were …
Study snapshot
Abstract
Neuroimaging findings in US government personnel and their family members involved in anomalous health incidents Pierpaoli C, Nayak A, Hafiz R, et al; NIH AHI Intramural Research Program Team. Neuroimaging findings in US government personnel and their family members involved in anomalous health incidents. JAMA. Published March 18, 2024. doi:10.1001/jama.2024.2424 Key Points Question Can a systematic evaluation using quantitative magnetic resonance imaging (MRI) metrics identify potential brain lesions in patients who have experienced anomalous health incidents (AHIs) compared with a well-matched control group? Findings In this exploratory study that involved brain imaging of 81 participants who experienced AHIs and 48 matched control participants, there were no significant between-group differences in MRI measures of volume, diffusion MRI–derived metrics, or functional connectivity using functional MRI after adjustments for multiple comparisons. The MRI results were highly reproducible and stable at longitudinal follow-ups. No clear relationships between imaging and clinical variables emerged. Meaning In this exploratory neuroimaging study, there was no significant MRI-detectable evidence of brain injury among the group of participants who experienced AHIs compared with a group of matched control participants. This finding has implications for future research efforts as well as for interventions aimed at improving clinical care for the participants who experienced AHIs. Abstract Importance US government personnel stationed internationally have reported anomalous health incidents (AHIs), with some individuals experiencing persistent debilitating symptoms. Objective To assess the potential presence of magnetic resonance imaging (MRI)–detectable brain lesions in participants with AHIs, with respect to a well-matched control group. Design, Setting, and Participants This exploratory study was conducted at the National Institutes of Health (NIH) Clinical Center and the NIH MRI Research Facility between June 2018 and November 2022. Eighty-one participants with AHIs and 48 age- and sex-matched control participants, 29 of whom had similar employment as the AHI group, were assessed with clinical, volumetric, and functional MRI. A high-quality diffusion MRI scan and a second volumetric scan were also acquired during a different session. The structural MRI acquisition protocol was optimized to achieve high reproducibility. Forty- nine participants with AHIs had at least 1 additional imaging session approximately 6 to 12 months from the first visit. Exposure AHIs. Main Outcomes and Measures Group-level quantitative metrics obtained from multiple modalities: (1) volumetric measurement, voxel-wise and region of interest (ROI)–wise; (2) diffusion MRI–derived metrics, voxel-wise and ROI-wise; and (3) ROI-wise within-network resting-state functional connectivity using functional MRI. Exploratory data analyses used both standard, nonparametric tests and bayesian multilevel modeling. Results Among the 81 participants with AHIs, the mean (SD) age was 42 (9) years and 49% were female; among the 48 control participants, the mean (SD) age was 43 (11) years and 42% were female. Imaging scans were performed as early as 14 days after experiencing AHIs with a median delay period of 80 (IQR, 36-544) days. After adjustment for multiple comparisons, no significant differences between participants with AHIs and control participants were found for any MRI modality. At an unadjusted threshold (P < .05), compared with control participants, participants with AHIs had lower intranetwork connectivity in the salience networks, a larger corpus callosum, and diffusion MRI differences in the corpus callosum, superior longitudinal fasciculus, cingulum, inferior cerebellar peduncle, and amygdala. The structural MRI measurements were highly reproducible (median coefficient of variation <1% across all global volumetric ROIs and <1.5% for all white matter ROIs for diffusion metrics). Even individuals with large differences from control participants exhibited stable longitudinal results (typically, <±1% across visits), suggesting the absence of evolving lesions. The relationships between the imaging and clinical variables were weak (median Spearman ρ = 0.10). The study did not replicate the results of a previously published investigation of AHIs. Conclusions and Relevance In this exploratory neuroimaging study, there were no significant differences in imaging measures of brain structure or function between individuals reporting AHIs and matched control participants after adjustment for multiple comparisons. Open access paper: jamanetwork.com
AI evidence extraction
Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.
Main findings
In 81 participants reporting AHIs and 48 matched controls, there were no significant between-group differences in volumetric MRI, diffusion MRI metrics, or resting-state functional connectivity after adjustment for multiple comparisons. Some differences were observed at an unadjusted P<.05 threshold, but longitudinal follow-up suggested stable measures and no evolving lesions; imaging-clinical correlations were weak.
Outcomes measured
- Quantitative MRI volumetric measures (voxel-wise and ROI-wise)
- Diffusion MRI–derived metrics (voxel-wise and ROI-wise)
- Resting-state functional MRI within-network functional connectivity (ROI-wise)
- Longitudinal stability/reproducibility of MRI measures
- Associations between imaging metrics and clinical variables
Limitations
- Exploratory study design
- Some findings only present at unadjusted statistical thresholds (P<.05) and not significant after multiple-comparisons adjustment
- Weak relationships between imaging and clinical variables
- Did not replicate results of a previously published AHI investigation
View raw extracted JSON
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"population": "US government personnel and their family members who experienced anomalous health incidents (AHIs), and matched control participants",
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"outcomes": [
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"Diffusion MRI–derived metrics (voxel-wise and ROI-wise)",
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"main_findings": "In 81 participants reporting AHIs and 48 matched controls, there were no significant between-group differences in volumetric MRI, diffusion MRI metrics, or resting-state functional connectivity after adjustment for multiple comparisons. Some differences were observed at an unadjusted P<.05 threshold, but longitudinal follow-up suggested stable measures and no evolving lesions; imaging-clinical correlations were weak.",
"effect_direction": "no_effect",
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"Weak relationships between imaging and clinical variables",
"Did not replicate results of a previously published AHI investigation"
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"keywords": [
"anomalous health incidents",
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}AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.
Identifiers and source
DOI: 10.1001/jama.2024.2424
PubMed: Not supplied
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