WASHINGTON – Returning soldiers with posttraumatic headache seemed to have a poorer treatment outcome than did those with idiopathic migraine, regardless of the concurrent presence of posttraumatic stress disorder, according to the findings of a retrospective study.
"This may suggest that there is some fundamental difference in the pain mechanism between the two headache groups," according to Dr. Jacqueline Rosenthal of the Madigan Army Medical Center, Tacoma, Wash. "One theory is that those with migraine may be more susceptible to stress as a central contributor to their headache," she said at the annual meeting of the American Headache Society.
Dr. Rosenthal and her colleagues retrospectively analyzed 441 solders, mean age 30 years, who presented to the center’s neurology clinic with headache. In addition to headache diagnosis, all of the patients underwent screening for PTSD, defined as a score of at least 50 on the PTSD Symptom Checklist.
All of those with posttraumatic headache had a history of head trauma within 7 days preceding the onset of the headache. In the migraine group, there were patients with head trauma, but the injury did not precipitate the headache, Dr. Rosenthal explained. Individual physicians determined the course of patient treatment, but those with PTSD also received behavioral therapy.
Dr. Rosenthal and her colleagues examined headache frequency at baseline and after 3 months of treatment in four subgroups: migraineurs with and without PTSD, and posttraumatic headache patients with or without PTSD.
Of the total, 171 (39%) had a diagnosis of idiopathic migraine; 270 (61%) were diagnosed with posttraumatic headache. One-third of the entire cohort, (145) also met the criteria for PTSD. Of these, significantly more had posttraumatic headache than migraine (72% vs. 28%).
Patients with migraine and PTSD had significantly more headache days per month than did those with migraine but no PTSD (21 vs. 14 days per month). But PTSD did not affect headache frequency in patients with posttraumatic headache (17 days per month with PTSD vs. 16 days without PTSD).
Chronic daily headache was significantly more common in migraineurs with PTSD than in those without (68% vs. 44%). But PTSD had no significant association with chronic daily headache in the posttraumatic headache group (58% with PTSD vs. 52% without).
Although outcomes were significantly worse in posttraumatic headache patients than in migraineurs, PTSD did not exert any significant effect in either group, Dr. Rosenthal said. Headache frequency declined by 16% in both groups with posttraumatic headache. Among those with migraine, headache frequency declined by 28% among those with PTSD and by 35% in those without the disorder, but that difference did not meet statistical significance.
A discussant pointed out that soldiers with posttraumatic headache might have experienced more serious or frequent blast injuries, which could account for the poorer outcomes. Dr. Rosenthal said the study did not account for any characteristics of the blast injuries incurred, but agreed that these could have an effect on treatment outcome.
Dr. Rosenthal did not report having any conflicts of interest. She indicated that the study conclusions did not necessarily reflect the views of the United States Army.