Autonomic Dysfunction May Distinguish Posttraumatic Headache From Migraine

Damian McNamara

July 12, 2018

SAN FRANCISCO — Assessing autonomic dysfunction may help clinicians distinguish headache related to persistent posttraumatic headache (PPTH) from migraine, new research shows.

Using the Composite Autonomic Symptom Scale 31 (COMPASS-31) investigators found those with PPTH scored significantly higher than their counterparts with migraine and healthy controls.

"The thing that seems to come out of this most consistently is the autonomic dysfunction," study author Levi Howard, MD, a neurology resident at the Mayo Clinic in Phoenix, Arizona, told Medscape Medical News.

"We definitely found larger autonomic dysfunction in our persistent PTH group compared to migraine, which is the primary phenotype right now that those patients fall under," he added.

The findings were presented here at the American Headache Society (AHS) Annual Meeting 2018.

Clinically Similar

The investigators noted that many patients with PPTH have a phenotype that meets diagnostic criteria for migraine or probable migraine. On the basis of their own clinical experience, the researchers also observed that patients with PPTH frequently had symptoms of autonomic dysfunction, raising the question of whether such symptoms may help distinguish PPTH from migraine.

To investigate, they compared COMPASS-31 questionnaire scores in 56 patients with PPTH: 30 patients with migraine and 36 healthy controls.

The validated tool includes 31 questions across six domains. These include bladder, gastrointestinal, orthostatic intolerance, pupillomotor, secretomotor, and vasomotor. Investigators compared between-subject groups using the Dunnet modified Tukey-Kramer test to account for unequal variances.

Many of the participants in the cross-sectional cohort study were recruited from the Phoenix VA. Almost half of those with PPTH (n = 24) experienced blast injuries. However, not all injuries leading to mild traumatic brain injury were related to military service. The PPTH group also experienced 13 falls, 9 sport injuries, 7 motor vehicle accidents, and 3 cases of blunt force trauma.

The mean age of participants in the three groups ranged from 38 to 41 years. The proportion of women was 34% in the PPTH group, 77% in the migraine group, and 47% in the control group.

Investigators found that autonomic dysfunction scores were consistently higher among those with PPTH compared with migraineurs and healthy controls.

The COMPASS-31 mean total weighted score was 37.22 in the PPTH group compared with 27.15 in the migraine group and 11.67 among healthy controls. The differences were statistically significant when PPTH was compared with migraine (P = .014) and in comparison with healthy controls (P = .001). They were also statistically significant for patients with migraine vs healthy controls (P = .001).

Lower Headache Burden

The mean COMPASS-31 domain scores were significantly higher for orthostatic intolerance: 4.80 in the PPTH vs 3.33 in the migraine group (P = .027). Bladder symptoms were likewise significantly higher in the persistent PTH group than in the migraine group, at 1.14 vs 0.47 (P = .02).

The COMPASS scores in patients with PPTH were similar to scores previously reported for patients with autonomic diseases, such as autonomic failure, small-fiber polyneuropathies, and postural orthostatic tachycardia syndrome.

The investigators also assessed headache burden.

"Interestingly, in the headache days per month, as well as the years of headache, the PPTH group had a lower headache burden compared to migraine," said Howard.

Participants with PPTH had lower mean headache frequency than those with migraine (16.2 vs 21.1 headache days per month; P = .001) and fewer years with headache (11.1 vs 24.1; P < .001).

"Objectively, you would think a lower headache burden would be associated with fewer autonomic symptoms, but that was not the case," Howard said. 

The current findings build on prior research that identified dysautonomia in patients with mild traumatic brain injury (Brain Sci. 2017;7:100) and postconcussion (Front Neurol. 2018;9:196).

The results also align with "our own clinical observations in the headache clinic at Mayo, where persistent PTH is often accompanied by orthostatic intolerance, specifically," said Howard.

Potential Treatment Target?

Commenting on the findings for Medscape Medical News, Matthew S. Robbins, MD, a neurologist at Montefiore Medical Center and associated professor of neurology at Albert Einstein College of Medicine in the Bronx, New York, described the research as "important."

"It investigates an unexplored symptom that we know is present in migraine, but it's typically not as severe as it is in other headache disorders."

"It could be the mechanisms that incite posttraumatic headache might, at the same time, incite autonomic symptoms. This could be a treatment target that in turn improves migraine," he added.

Howard said the study raises a few unanswered questions: "If we treat autonomic dysfunction, does it improve [PPTH]? In our clinical observations, it appears to."

It also remains to be seen whether autonomic symptoms contribute to accurate classification of PPTH vs migraine, he added.  

The International Headache Society's International Classification of Headache Disorders, 3rd edition, criteria for PTH include a headache reported to have developed within 7 days after injury to the head, regaining consciousness following the injury to the head, or discontinuation of medication(s) impairing ability to sense or report headache after the injury to the head. PPTH lasts longer than 3 months.

Howard noted that the 7-day onset component of the definition seems "somewhat arbitrary." If a patient presents with migraine-like symptoms and "if there is an inciting injury anywhere close, I think you should be suspicious that it could be a post-traumatic headache."

Howard and Robbins have disclosed no relevant financial relationships.

American Headache Society (AHS) Annual Meeting 2018. Abstract FHM03. Presented June 29, 2018.

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