Chronic Effects of Neurotrauma Consortium (CENC) multicentre study interim analysis: Differences between participants...

Compare characteristics and outcomes of combat-exposed military personnel with positive versus negative mild traumatic brain injury (mTBI) histories.

Recruitment was from registration lists and ambulatory clinics at four veterans administration hospitals.

Consented veterans and service members completing initial evaluation by September 2016 (n = 492).

Observational with cross-sectional analyses.

Multimodal assessments including structured interviews, record review, questionnaires, neuroendocrine labs and neurocognitive and sensorimotor performance.

In unadjusted comparisons to those absent lifetime mTBI, the mTBI positive group (84%) had greater combat exposure, more potential concussive events, less social support and more comorbidities, including asthma, sleeping problems and post-traumatic stress disorder. They also fared worse on all sensory and pain symptom scores and self-reported functional and global outcomes. They had poorer scores on Wechsler Adult Intelligence Scale-IV coding (processing speed), TMT-B (visual-motor integration and executive function) and two posturography subtests, but were otherwise equal to TBI negative participants on neurocognitive and sensorimotor testing and neuroendocrine levels.

Although differences in characteristics exist which were not adjusted for, participants with historical mTBI have greater symptomatology and life functioning difficulties compared with non-TBI. Performance measures were less dissimilar between groups. These findings will guide further research within this accruing cohort.