Self-reported mild TBI and postconcussive symptoms in a peacetime active duty military population: effect of multiple TBI history versus single mild TBI.
OBJECTIVE
To investigate the potential cumulative impact of mild traumatic brain injury (MTBI) on postconcussive symptoms.


METHODS
A total of 224 active duty soldiers reporting MTBI within 1 year of testing. For 101, this MTBI was their only reported traumatic brain injury (TBI); 123 had sustained at least 1 additional MTBI during their lifetime. A No TBI control group (n = 224) was included for comparison.


METHODS
Self-report symptoms data via questionnaire. Within time since injury subgroups (≤3 months; Post-3 months), symptom endorsement (no symptoms, 1 or 2 symptoms, 3+ symptoms) among soldiers with 1 MTBI was compared with that of soldiers with 2 or more MTBIs. Injured soldiers' symptom endorsement was compared with that of soldiers who had not sustained a TBI.


RESULTS
Among the recently injured (≤3 months), those with 2 or more MTBIs endorsed significantly more symptoms than those with 1 MTBI: 67% of soldiers with 2 or more MTBIs reported 3+ symptoms, versus 29% of One MTBI soldiers. Among Post-3 month soldiers, there were no significant differences between MTBI groups. Overall, soldiers with MTBI endorsed significantly more symptoms than those without TBI.


CONCLUSIONS
Past experience of MTBI may be a risk factor for increased symptom difficulty for several months postinjury. Clinicians should ascertain lifetime history of brain injury when evaluating patients for MTBI.
Defense and Veterans Brain Injury Center, Rockville, MD 20852, USA. kelly.j.miller2.ctr@us.army.mil
Kelly J
KJ
Miller
Brian J
BJ
Ivins
Karen A
KA
Schwab
D000328:Adult; D001288:Attention; D001924:Brain Concussion / Q000150:complications*; D001930:Brain Injuries / Q000150:complications*; D016022:Case-Control Studies; D003221:Confusion / Q000209:etiology; D004244:Dizziness / Q000209:etiology; D005221:Fatigue / Q000209:etiology; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D007508:Irritable Mood; D008297:Male; D008569:Memory Disorders / Q000209:etiology; D008889:Military Personnel; D057566:Self Report; D012893:Sleep Wake Disorders / Q000209:etiology; D011795:Surveys and Questionnaires; D014474:Unconsciousness / Q000209:etiology; D014481:United States