SAN DIEGO—Traumatic brain injury (TBI) resulting from a blast injury and TBI resulting from direct head trauma can lead to similarly significant and long-term effects in military veterans, reported James R. Couch, MD, PhD, at the 65th Annual Meeting of the American Academy of Neurology.
“Postconcussion syndrome produced by blast injury and direct head trauma is essentially the same for up to eight years postinjury,” said Dr. Couch, Professor of Neurology at the University of Oklahoma College of Medicine in Oklahoma City. “As far as gauging the postconcussion syndrome by symptoms related to the domains of postconcussion syndrome, the two modes of brain injury appear to be equivalent in their short- and longer-term effects.”
Postconcussion Syndrome in Military Veterans
Dr. Couch and colleagues analyzed 500 veterans (ages 20 to 62; 474 males) from the conflicts in Iraq and Afghanistan who had had a deployment-related TBI and were referred to a TBI clinic. A neurologist or physician’s assistant with additional training in TBI examined all participants. The TBIs had occurred between one and eight years prior to analysis.
The investigators administered a standard TBI screen concerning events that had occurred around the time of the TBI, and they evaluated the following symptoms to represent postconcussion syndrome: headache, dizziness, balance difficulty, poor coordination, difficulty with decision-making, and depression. These symptoms were measured using a scale of 1 (no symptoms) to 5 (very severe). “The scale reflected the interference in daily life or extent of the problem presented by the symptom and not just the severity of a single headache or other incident,” noted Dr. Couch.
Depression was measured with use of the Beck Depression Inventory. For longitudinal comparison, participants were classified into two groups: those who had had a TBI one to four years prior to analysis and those who had had a TBI five to eight years prior to analysis.
Among the veterans, 383 had a blast injury (247 at one to four years, 136 at five to eight years) and 114 had a direct head trauma (63 at one to four years and 51 at five to eight years), and data were missing from three participants. After comparing the occurrence of neurologic symptoms and depression scores between blast injury and direct head trauma in subjects for the entire group and for subgroups at one to four and five to eight years postinjury, the researchers observed no significant differences.
Of the 474 veterans with mild TBI as measured by loss of consciousness of less than 30 minutes, 357 (75%) had loss of consciousness of less than one minute and could be designated as having very mild TBI, according to Dr. Couch. “This suggests that even very mild TBI, by the measure of duration of loss of consciousness, can produce a significant and prolonged postconcussion syndrome, whether of blast or direct head trauma origin,” he said. Seventeen veterans had loss of consciousness of 30 minutes or greater, and nine were unable to report how long they had lost consciousness.
“The data presented suggest that the postconcussion is a major problem for veterans with mild TBI,” said Dr. Couch. “Only 5% of the subjects in this cohort had TBI consistent with moderate to severe TBI or did not know duration of the loss of consciousness.”
Headache, Cognitive Problems Among Lasting Effects of TBI
Headache was the most commonly reported symptom by the blast and trauma groups, with about half the subjects reporting a severe headache one to four years and five to eight years postinjury. Severe difficulty with decisions was the next most common symptom, followed by balance, dizziness, and coordination problems. Depression was minimal to none in more than 90% of veterans.
“Headache and cognitive problems are major contributors to the continuing postconcussion syndrome problem and can continue to cause significant difficulties for the TBI victim years after the injury,” Dr. Couch concluded. “The other symptoms also present significant problems for periods of up to eight years. Much further study will be needed to define the long-term course of TBI.”
—Colby Stong
Editor