Headaches Persist Up to 8 Years Post-Concussion
June 25, 2012 (Los Angeles, California) — Headaches, as well as neurologic and psychiatric symptoms related to post-concussion syndrome (PCS), can last up to 8 years after a traumatic brain injury (TBI), a new study of veterans has shown.

"Many of the up to 25% of soldiers returning from combat zones who have suffered a significant TBI continue to experience the after-effects over time," said study author, James R. Couch, MD, PhD, professor of neurology, at The University of Oklahoma Health Sciences Center, Oklahoma City.

"It's really frightening that a lot of these guys are not getting better," Dr. Couch told Medscape Medical News. "Some of them were injured 5, 6, and 7 years ago and are still having significant difficulties."

"The results suggest that these veterans need extended follow-up and ongoing medical and psychiatric care," said Dr. Couch. "The prolonged symptoms are something the Veterans Administration is going to be dealing with for a long time" because most of these returning soldiers are relatively young.

Another study using the same database confirmed a correlation between TBI-related headache and depression.

Both studies were presented here at the American Headache Society's 54th Annual Scientific Meeting.

Signature Problem

"Traumatic brain injury has become the 'signature' injury for the current wars in Iraq and Afghanistan, where soldiers deal with roadside bombs, blasts from mortar shells, rockets, and other explosives, in addition to the risk of head trauma from shrapnel, debris, falls, and physical assaults," said Dr. Couch.

Experts have noted that modern weapons are designed to maximize the explosive force transmitted to a target. They are refined in such a way that they intensify the generated force or shock waves and cause maximum damage.

For the first study, investigators retrospectively evaluated post-concussion syndrome in 500 veterans confirmed to have a deployment-related TBI (D-TBI). These veterans were screened for depression and were asked detailed questions about their TBI, including the mode of injury (ie, related to a blast, fall, assault, motor vehicle accident, or combination of these factors) and the circumstances surrounding the TBI. Additional questions dealt with symptoms that were being experienced at the time of the D-TBI.

"About two thirds of injuries in this group were related to the force of a blast from an explosion," said Dr. Couch. Unlike with typical head injuries such as those sustained in a motor vehicle accident, the skull and the brain do not move in the case of a blast injury. "The patient feels the overpressure wave from the blast," said Dr. Couch. "The energy that goes into the brain produces this post-concussion syndrome without having a concussion, so to speak."

Study participants rated the severity of each symptom as none, mild, moderate, severe, or very severe. All symptoms, except for depression, were scored on a 5-point scale, with the highest scores being the most severe.

Researchers pooled the categories of mild and moderate and those of severe and very severe and divided patients into 2 cohorts by time since their deployment: 1-4 years and 5-8 years.

Study findings include a nonsignificant tendency for the symptoms of headache, dizziness, balance difficulty, and difficulty with decisions to worsen between the 2 time periods. For example, in the headache assessment, of 310 veterans in the 1-4 year cohort, almost half (49.0%) had mild or moderate and 46.5% had severe symptoms, but among 187 veterans in the 5-8 year cohort, rates were 44.9% and 51.3%, respectively (P = .28).

For poor coordination, the between-group tendency to worsen was marginally significant (P > .09). "There was some suggestion that this would become significant if the sample size were bigger," said Dr. Couch. A statistically significant (P = .046) tendency toward an increase in depression was noted in the 1-4 year cohort compared with the 5-8 year group.

Outcomes for veterans suffering only blast injuries were similar to those reported for those who had suffered other head injuries—a result that Dr. Couch found surprising.

These study results challenge the notion that everyone who gets their "bell rung" from a head injury will be back to normal if they just "wait awhile until the cobwebs get cleared out," said Dr. Couch. "This might be so in most cases, but not all," he said.

Dr. Couch stressed that the study was retrospective, and investigators did not consider factors such as alcohol or drug abuse, divorce, loss of employment, or other injuries.

In any case, he thinks a long-term prospective study that follows the same subjects over a period of time is warranted.

"Pure" Blast Injury

Asked to comment on the differences in resulting headaches after a blast injury compared with another type of traumatic brain injury, Sylvia Lucas, MD, from Neurology and Rehabilitation Medicine, at the University of Washington, Seattle, said it is difficult to determine whether there is such a thing as a "pure" blast injury.

"If you're subjected to a blast wave and you're in a tank, chances are you're going to be thrown out of the jeep and hit the ground, or your head's going to be smashed to the side of the vehicle, so it's going to be a multiple injury. You'll be subjected to a blast wave but also have a direct head trauma."

"Any injury, whether it's from a direct blunt trauma or a blast, can trigger headaches," she said.

"If it's enough of a pressure wave to affect the cortex under the bone, it's probably going to trigger cortical spreading depression and cause the headache."

Depression and Headache

In another study using the same database, Dr. Couch and colleagues found a strong correlation between headache severity and extent of depression in 446 veterans. Results suggest that depression should be identified and treated along with the headache.

The incidence of headache was 95% to 97% over the 8-year period, with almost half of headache sufferers manifesting severe or very severe headache problems. Proportions of the cohort with severe/very severe, mild/moderate, and no headache remained the same in the 1-4 and 5-8 year post-TBI groups.

As for depression, evaluated using the Beck Depression Inventory II (BDI-II), some 30% to 40% of both groups had minimal or mild/moderate depression. A modest decrease was seen in those with no depression, along with an increase in those with minimal or mild/moderate depression among 5-8 year compared with 1-4 year post-TBI participants.

Dr. Couch said that he was not surprised by these findings because other research has shown that headache and depression may coexist, possibly because of involvement of genes related to the serotonin system.

Approached for a comment on this research, Randolph W. Evans, MD, clinical professor of neurology at Baylor College of Medicine, Houston, Texas, said he agreed that having symptoms that may worsen and last up to 8 years represents a significant burden.

"Trying to lessen the suffering of these veterans will be a major challenge for health care providers," he told Medscape Medical News.

"The research also points to psychiatric co-morbidity," said Dr. Evans. He added, however, that a very small percentage of these soldiers might have chronic traumatic encephalopathy, a condition that is getting increasing attention in debates surrounding concussions in professional sports.

Dr. Evans noted that this study is a retrospective sample that may not be representative of all soldiers with post-concussion syndrome with blast trauma.

American Headache Society 54th Annual Meeting: Posters 82 and 83. Presented June 21, 2012.