Comprehensive Evaluation of Healthy Volunteers Using Multi-Modality Brain Injury Assessments: An Exploratory, Observational Study

Abstract

Introduction: Even though mild traumatic brain injury is common and can result in persistent symptoms, traditional measurement tools can be insensitive in detecting functional deficits after injury. Some newer assessments do not have well-established norms, and little is known about how these measures perform over time or how cross-domain assessments correlate with one another. We conducted an exploratory study to measure the distribution, stability, and correlation of results from assessments used in mild traumatic brain injury in healthy, community-dwelling adults.Materials and Methods: In this prospective cohort study, healthy adult men and women without a history of brain injury underwent a comprehensive brain injury evaluation that included self-report questionnaires and neurological, electroencephalography, sleep, audiology/vestibular, autonomic, visual, neuroimaging, and laboratory testing. Most testing was performed at 3 intervals over 6 months.Results: The study enrolled 83 participants, and 75 were included in the primary analysis. Mean age was 38 years, 58 were male, and 53 were civilians. Participants did not endorse symptoms of post-concussive syndrome, PTSD, or depression. Abnormal neurological examination findings were rare, and 6 had generalized slowing on electroencephalography. Actigraphy and sleep diary showed good sleep maintenance efficiency, but 21 reported poor sleep quality. Heart rate variability was most stable over time in the sleep segment. Dynavision performance was normal, but 41 participants had abnormal ocular torsion. On eye tracking, circular, horizontal ramp, and reading tasks were more likely to be abnormal than other tasks. Most participants had normal hearing, videonystagmography, and rotational chair testing, but computerized dynamic posturography was abnormal in up to 21% of participants. Twenty-two participants had greater than expected white matter changes for age by MRI. Most abnormal findings were dispersed across the population, though a few participants had clusters of abnormalities.Conclusions: Despite our efforts to enroll normal, healthy volunteers, abnormalities on some measures were surprisingly common.Trial Registration: This study was registered at www.clinicaltrials.gov, trial identifier NCT01925963.

10.5 T MRI static field effects on human cognitive, vestibular, and physiological function

“…those recruited for this study) with no history of balance or vestibular issues is complex. For example, abnormal caloric findings range from 0/30 (0%) (61) to 3/49 (3%) (62) to 22/75 (30%) (63); our finding of 7/26 (27%) is within this range. For abnormal positional nystagmus, reports include 0/75 (0%) (63), 16/29 (55%) (64), 65/89 (73%) (65), and 66/75 (88%) (66); again, our finding of 6/26 (23%) is within the range.…”

Structural and Volumetric Brain MRI Findings in Mild Traumatic Brain Injury

“…Primary study results are published elsewhere. 14,15 The United States Army Medical Research and Materiel Command institutional review board approved the studies, and participants provided written informed consent.…”

Interval-censored survival analysis of mild traumatic brain injury with outcome based neuroimaging clinical applications

“…Incidence of WMH in normative populations is varied, with some reporting low incidence [55][56][57] and others higher incidence. 54,58 Comparing WMH in TBI versus controls, some studies have found no difference, while some have found changes in subcortical predominance of lesions 59 ; others have documented trends approaching significance. 54 Tate et al, did not find significant differences in WMH between controls and TBI subjects, but did find that TBI patients with WMH had significantly worse cognitive deficits than those without WMH.…”