New findings provide potential explanations for the very high percentage of post-traumatic disorders in combat, as outlined in Psychotherapy and Psychosomatics. Mild traumatic brain injury (mTBI) has been called the 'signature' injury of recent wars in Iraq and Afghanistan. Estimates of mTBI in deployed personnel are as high as 20%. Postconcussive symptoms (PCS), regarded as the core problem following mTBI, comprise headaches, dizziness, sensitivity to light and sound, fatigue, and concentration deficits. Although PCS have traditionally been presumed to result from neurological insult, evidence points to a role of psychological factors in these symptoms. This study represents the first report of military personnel (US military personnel serving in Iraq between September 2006 and September 2007) assessed in theatre shortly after exposure to a blast.
There were 685 personnel (mean age 26.4 ± 6.8 years) who had been exposed to an explosive blast. mTBI was defined as documented occurrence of injury to the head, loss of consciousness for less than 30 min, posttraumatic amnesia of less than 24 h, and normal computerized tomography findings with no focal neurological deficit or intracranial complications. A total of 567 (83%) participants suffered an mTBI, and 118 (17%) had no TBI. Six personnel were excluded because of moderate/severe TBI.
The 567 (83%) participants with an mTBI were more likely to be males (p = 0.04) and Marines (p < 0.0001) than the 118 (17%) participants with no TBI. At least one prior blast-related TBI was reported by 13%. Personnel diagnosed with mTBI were more likely to report a prior blast-related TBI (14 vs. 5%; χ2 = 5.8, d.f. = 1, p = 0.016), more likely to meet the criteria for PTSD without the minimum 1-month duration (25 vs. 11%; χ2 = 10.8, d.f. = 1, p = 0.001), and more likely to meet the criteria for PCS using a diagnostic threshold of at least three PCS based on the ICD-10 criteria (62 vs. 31%; χ2 = 37.1, d.f. = 1, p = 0.001). In the multiple regression analysis, PCS severity was predicted by a diagnosis of mTBI, longer duration since blast, and PTSD severity.
This is the first study to show an effect of stress reactions on PCS in blast-exposed combat troops in the acute combat setting over and above a diagnosis of mTBI. The authors suggested that management of PCS needs to recognize the role of acute posttraumatic stress responses in the immediate aftermath of a blast injury. Attributing the array of somatic sensations experienced after battle to mTBI may create the perception that the individual has suffered a disabling and permanent brain injury.