Blast-related mild traumatic brain injury in the acute phase: acute stress reactions partially mediate the relationship between loss of consciousness and symptoms.

PRIMARY

OBJECTIVE

The objective was to compare symptoms in service members diagnosed with a blast-related mTBI (mild traumatic brain injury) with a loss of consciousness (LOC) to those without LOC.

RESEARCH

DESIGN

Clinicians saw US military personnel within 72 hours of sustaining a blast-related mTBI and at a follow-up visit 48-72 hours later (n = 210).

METHODS AND PROCEDURES: Demographics, post-concussive symptoms, diagnosis of acute stress reaction (ASR) and simple reaction time data from the Automated Neuropsychological Assessment Metric (ANAM) were collected.

MAIN OUTCOMES AND

RESULTS

ASRs were significantly more likely in patients reporting LOC versus patients reporting no LOC. At the first post-injury visit, LOC was associated with difficulty sleeping, hearing loss, memory problems and reporting more symptoms. A follow-up analysis explored if symptomatic differences were influenced by ASR. Adjusting for ASR, the statistical relationships between LOC and symptoms were weaker (i.e. reduced Odds Ratios). At the follow-up visit, difficulty sleeping was associated with LOC before and after adjusting for ASR. Patients with both ASR and LOC had the slowest simple reaction times.

CONCLUSIONS

Results suggest ASR may partially mediate symptom presentation and cognitive dysfunction in the acute phase following blast-related mTBI. Future research is warranted.