Treatment outcomes of chronic post-traumatic headaches after mild head trauma in US soldiers: an observational study.

Background: he effectiveness of medical therapies for chronic post-traumatic headaches (PTHs) attributable to mild head trauma in military troops has not been established.

Objective: To determine the treatment outcomes of acute and prophylactic medical therapies prescribed for chronic PTHs after mild head trauma in US Army soldiers.

Methods: A retrospective cohort study was conducted with 100 soldiers undergoing treatment for chronic PTH at a single US Army neurology clinic. Headache frequency and Migraine Disability Assessment (MIDAS) scores were determined at the initial clinic visit and then again by phone 3 months after starting headache prophylactic medication. Response rates of headache abortive medications were also determined. Treatment outcomes were compared between subjects with blast-related PTH and non-blast PTH.

Results: Ninety-nine of 100 subjects were male. Seventy-seven of 100 subjects had blast PTH and 23/100 subjects had non-blast PTH. Headache characteristics were similar for blast PTH and non-blast PTH with 96% and 95%, respectively, resembling migraine. Headache frequency among all PTH subjects decreased from 17.1 days/month at baseline to 14.5 days/month at follow-up (P = .009). Headache frequency decreased by 41% among non-blast PTH compared to 9% among blast PTH. Fifty-seven percent of non-blast PTH subjects had a 50% or greater decline in headache frequency compared to 29% of blast PTH subjects (P =.023). A significant decline in headache frequency occurred in subjects treated with topiramate (n = 29, -23%, P = .02) but not among those treated with a low-dose tricyclic antidepressant (n = 48, -12%, P = .23). Seventy percent of PTH subjects who used a triptan class medication experienced reliable headache relief within 2 hours compared to 42% of subjects using other headache abortive medications (P = .01). Triptan medications were effective for both blast PTH and non-blast PTH (66% response rate vs 86% response rate, respectively; P = .20). Headache-related disability, as measured by mean MIDAS scores, declined by 57% among all PTH subjects with no significant difference between blast PTH (-56%) and non-blast PTH (-61%).

Conclusions: Triptan class medications are usually effective for aborting headaches in military troops with chronic PTH attributed to a concussion from a blast injury or non-blast injury. Topiramate appears to be an effective headache prophylactic therapy in military troops with chronic PTH, whereas low doses of tricyclic antidepressants appear to have little efficacy. Chronic PTH triggered by a blast injury may be less responsive to commonly prescribed headache prophylactic medications compared to non-blast PTH. These conclusions require validation by prospective, controlled clinical trials.