Experts were in agreement that the criteria should include PTH phenotype, TBI mechanism and TBI comorbidities.
Emily Schlitz-Fortenberry, MD
A recent study has highlighted the need for an updated version of the International Classification of Headache Disorders (ICHD-3) criteria for posttraumatic headache (PTH). Emily Schlitz-Fortenberry, MD, neurologist, University of Alabama at Birmingham Hospital, presented the consensus at the 2021 Virtual American Headache Society (AHS) 63rd Annual Scientific Meeting, June 3-6.1
“An accurate and consistent definition for PTH is essential to guarantee that accumulating data can be meaningfully interpreted and used as a foundation for subsequent advancements in PTH diagnosis and treatment,” Schlitz-Fortenberry and colleagues wrote. The investigators stressed the fact that PTH is the most common physical complaint following traumatic brain injury [TBI]—with up to a 90% prevalence—and many reports of PTH (18% to 22%) continue after 1 year. Additionally, military service members are at high risk for PTH, with an estimated annual incidence of TBI of 10,000-15,000.
Current ICHD-3 criteria define PTH as a secondary headache disorder which develops within 7 days of TBI or within 7 days to 3 months after a TBI. Although, it also states that these time periods are “arbitrary.” The investigators regard the criteria as overly restrictive, as natural history studies have shown that up to 20% of PTH occur within 3-12 months after TBI.
To address these issues, Schlitz-Fortenberry and colleagues conducted a cross-sectional, observational study in which they interviewed 43 Veterans’ Affairs (VA)-based providers and 13 community-based providers specializing in headache management between October and November 2019. Providers were asked about the benefits and limitations of ICHD-3 criteria as it pertained to PTH.
The interviews yielded 4 common themes regarding ICHD-3 benefits for PTH among both types of providers. One, ICHD-3 criteria for PTH is beneficial from a research perspective; 2, the criteria improve diagnostic accuracy; 3, it legitimizes the disorder; and 4, it is important for reimbursement.
Six themes arose among both types of providers regarding ICHD-3's limitations pertaining to PTH. One, the time frame outlined for PTH is too restrictive; 2, PTH phenotypes are not incorporated in the criteria; 3, the criteria is less helpful for clinical management; 4, important TBI comorbidities are not addressed by the criteria; 5, diagnosis of PTH based on the criteria limits therapies providers can offer dur to a lack of FDA-approved therapies; and 6, the important factor of mechanism of injury of the original TBI is not currently accounted for in the criteria.
“Expert consensus agrees there is a significant need for an updated version of the ICHD-3 criteria for PTH phenotype, mechanism of TBI, and comorbid TBI symptoms need to be incorporated into the new ICHD-3 definition, in order to also make it a clinically useful tool that more completely characterizes the spectrum of PTH,” Schlitz-Fortenberry and colleagues concluded.
In addition to recognizing the need to include the aforementioned factors, the investigators also call for the expansion of the time frame of PTH set forth in the criteria. They recommended the time frame to also include headache development within 3 to 6 months following TBI, with most participants reporting a causal association between TBI and PTH within 3 months.
The VA has also recently initiated a study investigating the use of the gammaCore Sapphire device from electroCore for the treatment of PTH. The study, known as GAP-PTH, will be randomized, multicenter, double-blind, and sham-controlled. It will be directed by the VA Headache Centers of Excellence at the West Haven VA Medical Center, in Connecticut, and will enroll up to 100 veterans.2
GammaCore is a handheld, non-invasive vagus nerve stimulation medical therapy device. It was approved for the treatment of episodic cluster headache pain in 2017, and this indication was later expanded to migraine pain in January 2018 and adjunctive preventive treatment of cluster headache in December 2018. The portable device can be self-administered as needed and is placed over the vagus nerve in the neck, which is stimulated via a mild electrical signal.3
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