Deployed US military service members with concussion commonly have comorbid conditions that may influence their clinical course and overall recovery, according to study results published in Headache.
Previous studies have established an association between comorbidities and chronic post-concussive syndrome, which may also be present immediately following a deployment-related concussion. The objective of this study was to describe the clinical characteristics of a group of deployed US military service members following deployment-related concussion.
This study, which was a retrospective chart review, was performed by the treating neurologist of 40 deployed service members during Operation Enduring Freedom between October 2010 and April 2011. During this time, the neurologist performed comprehensive neurologic evaluations on each patient and collected data on clinical symptoms and comorbidities, including evidence of migraine that existed prior to concussion.
Results revealed that headache was the most frequently reported acute symptom after concussion, which occurred in 38 (95%) of the service members. After headache, the most frequently reported symptoms were insomnia (n=33; 82.5%), impaired concentration (n=25; 62.5%), and tinnitus (n=24; 63% with 2 unreported), followed by impaired memory, nausea, dizziness, irritability, anxiety, impaired balance, acute stress, depression, hearing loss, and visual symptoms.
The most frequent co-occurring conditions identified as potentially contributing to clinical presentation were concurrent injuries, anxiety and/or depression, painkiller overuse, and acute stress reaction. The most frequent chronic comorbidities identified were chronic headache, history of more than 2 recurrent concussions, anxiety and/or depression, longstanding insomnia, post-traumatic stress disorder, painkiller overuse, and severe musculoskeletal pain.
A history of headache pre-deployment was reported by 25 (63%) service members. Of these 25 service members, 21 (84%) reported migraine features or triggers. Thirty-four of the 40 service members (85%) were initially treated with nonsteroidal anti-inflammatory drugs for their headaches, with 26 reporting a positive response. Sixteen service members were subsequently treated with triptans, with 12 reporting moderate though incomplete treatment response within 2 hours.
This study had several limitations. First, the study had a relatively small sample size and findings may not be generalized to all service members following concussion regardless of deployment status. Second, data were based on self-report by service members, presenting a risk for memory bias. Third, some patients in the cohort had concussions during the current deployment and prior to deployment, which may have added to the complexity of interpreting clinical presentation. Lastly, data was lacking on pre-deployment annual health assessments performed on service members.
The study researchers concluded that post-traumatic headaches secondary to blast injury may be associated with co-occurring conditions in deployed US military service members and that earlier diagnosis of migraine may allow opportunities to optimize pharmacologic management and improve the clinical course following concussion.
Scott BR, Uomoto JM, Barry ES. Impact of pre-existing migraine and other co-morbid or co-occurring conditions on presentation and clinical course following deployment-related concussion [published online January 3, 2020]. Headache. doi: 10.1111/head.13709