Interrelations between migraine-like headache and persistent post-traumatic headache attributed to mild traumatic brain injury: a prospective diary study

DOI: https://doi.org/10.1186/s10194- 020- 01202- 6

Abstract-Summary Persistent post-traumatic headache (PTH) is a common sequela of mild traumatic brain injury (TBI) and retrospective assessments have found a migraine-like pheno- type to be very frequent.

Outcomes were the proportion of monthly headache days of any intensity that met the criteria for a migraine-like day or TTH-like day, as well as the correspond- ing figures for monthly headache days of moderate to severe intensity.

After diary review, we found that monthly headache days were exclusively migraine-like in 24 of 64 patients (38%) and exclusively TTH-like days in 8 of 64 patients (13%).

Considering only monthly headache days of moderate to severe intensity, the corresponding figures were 35 of 64 patients (55%) for migraine-like days and 8 of 64 patients (13%) for TTH-like days.

The following headache phenotypes were assigned based on diary review: chronic migraine-like (n = 47, 73%), combined episodic migraine-like and chronic TTH-like (n = 9, 13%), and ‘pure’ chronic TTH-like (n = 8, 13%).

A migraine-like phenotype is common in patients most adversely affected by persistent PTH, although some patients did have a pure chronic TTH-like phenotype.

Introduction PTH is characterized by onset of headache within 7 days of mild TBI and, if the headache persists for at least 3 months, the term persistent PTH is used [369].

While ICHD-3 conceptualizes persistent PTH as a secondary headache disorder, the definition and diagnosis remains controversial and some contest that persistent PTH is ‘trauma-triggered migraine [370].

This is supported by the observation that persistent PTH most often mimics a migraine-like headache phenotype in clinic-based studies [371, 372], leading to use of the term ‘post-traumatic migraine’ [373].

As a step towards clarifying the relationship of persistent PTH to migraine, we performed a 28-day prospective diary study in patients with persistent PTH who had at least eight monthly headache days of moderate to severe intensity.

2.3 Comorbidities

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Methods Possible headache phenotypes included the following options: Episodic migraine- like, defined as headache occurring on ≥1 day per month, which exclusively fulfills the criteria for a migraine-like day, but does not meet the requirement for a chronic migraine-like phenotype (see below).

Chronic TTH-like, defined as headache occurring on ≥15 days per month, which

exclusively fulfills the criteria for a TTH-like day.

Combined episodic migraine-like and episodic TTH-like, defined as headache occurring on 2–15 days per month, which, on ≥1 day per month fulfills the criteria for a migraine-like day, and on ≥1 day per month fulfills the criteria for a TTH-like day, but does not meet the requirement for a chronic migraine-like phenotype (see above).

Combined episodic migraine-like and chronic TTH-like, defined as headache occurring on > 15 days per month, which, on ≥15 days per months fulfills the crite- ria for a TTH-like day, and on 1–7 days per months fulfills the criteria for a migraine- like day.

Results The mean (SD) headache frequency was 26.6 (2.4) days per month in patients with a chronic migraine-like phenotype, 24.6 (3.8) days per month in those with a com- bined episodic migraine-like and chronic TTH-like phenotype, and 26.6 (3.6) days per month in patients with a pure chronic TTH-like phenotype.

In terms of headache days of moderate to severe intensity, the mean (SD) fre- quency was 19.9 (6.5) days per month in patients with a chronic migraine-like phe- notype, 17.7 (7.0) days per month in those with a combined episodic migraine-like and chronic TTH-like phenotype, and 20.3 (5.9) days per month in patients with a pure chronic TTH-like phenotype.

If considering only overlap of monthly migraine-like days with monthly head- ache days of moderate to severe intensity, 35 of 64 patients (55%) had 100% overlap while 39 of 64 (61%) at least 75% overlap.

Discussion Of 64 patients with persistent PTH and at least eight monthly headache days of moderate to severe intensity, we collected prospective diary data to examine the overlap of monthly migraine-like days with monthly headache days.

Future diary studies should include larger cohorts to identify subgroups of patients with PTH based on their headache phenotype (e.g. migraine-like, TTH- like) and personal history of primary headache disorder (e.g. pre-existing migraine). 7An important implication of the present diary study is that some individuals with persistent PTH do not experience migraine-like headache, which confirms pre- vious reports based on phenotype assessment by questionnaire or interview [371, 374–378].

The included patients with persistent PTH were mostly assigned with a migraine- like phenotype, although they did not have a personal history of migraine [379–382].

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2 Mechanisms

This was intended as we aimed to assess the overlap of monthly migraine-like

days with monthly headache days in patients most burdened by persistent PTH.

Conclusions These findings—at minimum—dismiss the notion that persistent PTH is trauma- triggered migraine.

Further studies are needed to ascertain similarities and differences of biological

underpinnings between persistent PTH and migraine.

Acknowledgement A machine generated summary based on the work of Ashina, Håkan; Iljazi, Afrim; Amin, Faisal M.; Ashina, Messoud; Lipton, Richard B.; Schytz, Henrik W. 2020 in The Journal of Headache and Pain.

Prevalence and comorbidity of migraine headache: results from the Singapore Mental Health Study 2016