Posttraumatic Headache

OBJECTIVE

This article provides an overview of the epidemiology, diagnosis, clinical presentation, pathophysiology, prognosis, and treatment of posttraumatic headache attributed to mild traumatic brain injury (mTBI).

LATEST DEVELOPMENTS

The International Classification of Headache Disorders, Third Edition requires that posttraumatic headache begin within 7 days of the inciting trauma. Although posttraumatic headache characteristics and associated symptoms vary, most commonly there is substantial overlap with symptoms of migraine or tension-type headache. New insights into posttraumatic headache pathophysiology suggest roles for neuroinflammation, altered pain processing and modulation, and changes in brain structure and function. Although the majority of posttraumatic headache resolves during the acute phase, about one-third of individuals have posttraumatic headache that persists for at least several months. Additional work is needed to identify predictors and early markers of posttraumatic headache persistence, but several potential predictors have been identified such as having migraine prior to the mTBI, the total number of TBIs ever experienced, and the severity of initial symptoms following the mTBI. Few data are available regarding posttraumatic headache treatment; studies investigating different treatments and the optimal timing for initiating posttraumatic headache treatment are needed.

ESSENTIAL POINTS

Posttraumatic headache begins within 7 days of the causative injury. The characteristics of posttraumatic headache most commonly resemble those of migraine or tension-type headache. Posttraumatic headache persists for 3 months or longer in about one-third of individuals. Additional studies investigating posttraumatic headache treatment are needed.

Identification of brain areas in mice with peak neural activity across the acute and persistent phases of post-traumatic headache

BACKGROUND

Post-traumatic headache is very common after a mild traumatic brain injury. Post-traumatic headache may persist for months to years after an injury in a substantial proportion of people. The pathophysiology underlying post-traumatic headache remains unknown but is likely distinct from other headache disorders. Identification of brain areas activated in acute and persistent phases of post-traumatic headache can provide insights into the underlying circuits mediating headache pain. We used an animal model of mild traumatic brain injury-induced post-traumatic headache and c-fos immunohistochemistry to identify brain regions with peak activity levels across the acute and persistent phases of post-traumatic headache.

METHODS

Male and female C57BL/6 J mice were briefly anesthetized and subjected to a sham procedure or a weight drop closed-head mild traumatic brain injury . Cutaneous allodynia was assessed in the periorbital and hindpaw regions using von Frey filaments. Immunohistochemical c-fos based neural activity mapping was then performed on sections from whole brain across the development of post-traumatic headache (i.e. peak of the acute phase at 2 days post- mild traumatic brain injury), start of the persistent phase (i.e. >14 days post-mild traumatic brain injury) or after provocation with stress (bright light). Brain areas with consistent and peak levels of c-fos expression across mild traumatic brain injury induced post-traumatic headache were identified and included for further analysis.

RESULTS

Following mild traumatic brain injury, periorbital and hindpaw allodynia was observed in both male and female mice. This allodynia was transient and subsided within the first 14 days post-mild traumatic brain injury and is representative of acute post-traumatic headache. After this acute post-traumatic headache phase, exposure of mild traumatic brain injury mice to a bright light stress reinstated periorbital and hindpaw allodynia for several hours - indicative of the development of persistent post-traumatic headache. Acute post-traumatic headache was coincident with an increase in neuronal c-fos labeling in the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and the nucleus accumbens. Neuronal activation returned to baseline levels by the persistent post-traumatic headache phase in the spinal nucleus of the trigeminal caudalis and primary somatosensory cortex but remained elevated in the nucleus accumbens. In the persistent post-traumatic headache phase, coincident with allodynia observed following bright light stress, we observed bright light stress-induced c-fos neural activation in the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and nucleus accumbens.

CONCLUSION

Examination of mild traumatic brain injury-induced changes in peak c-fos expression revealed brain regions with significantly increased neural activity across the acute and persistent phases of post-traumatic headache. Our findings suggest mild traumatic brain injury-induced post-traumatic headache produces neural activation along pain relevant pathways at time-points matching post-traumatic headache-like pain behaviors. These observations suggest that the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and nucleus accumbens may contribute to both the induction and maintenance of post-traumatic headache.

Sensory hypersensitivities are associated with post-traumatic headache-related disability

OBJECTIVE

To examine whether sensory hypersensitivity contributes to headache-related disability in a secondary analysis of patients with post-traumatic headache.

BACKGROUND

Up to one-third of individuals with traumatic brain injuries report persistent headache 3 months post-injury. High rates of allodynia and photophobia have been observed in clinical studies and animal models of post-traumatic headache, but we do not fully understand how sensory amplifications impact post-traumatic headache-related disability.

METHODS

We identified a cross-sectional sample of patients from the American Registry for Migraine Research database with new or worsening headaches post-head injury from 2016 to 2020 and performed a secondary analysis of those data. We modeled the relationship between sensory sensitivity and Migraine Disability Assessment scores using questionnaires. Candidate variables included data collection features (study site and year), headache-related and general clinical features (headache frequency, migraine diagnosis, abuse history, sex, age, cognitive and affective symptom scores), and sensory symptoms (related to light, sound, and touch sensitivity).

RESULTS

The final sample included 193 patients (median age 46, IQR 22; 161/193, 83.4% female). Migraine Disability Assessment scores ranged from 0 to 260 (median 47, IQR 87). The final model included allodynia, hyperacusis, photosensitivity, headache days per month, abuse history, anxiety and depression, cognitive dysfunction, and age (R2  = 0.43). An increase of one point in allodynia score corresponded to a 3% increase in headache disability (95% CI: 0%-7%; p = 0.027), an increase of one-tenth of a point in the photosensitivity score corresponded to a 12% increase (95% CI: 3%-25%; p = 0.002), and an increase of one point in the hyperacusis score corresponded to a 2% increase (95% CI: 0%-4%; p = 0.016).

CONCLUSIONS

Increased photosensitivity, allodynia, and hyperacusis were associated with increased headache-related disability in this sample of patients with post-traumatic headache. Symptoms of sensory amplification likely contribute to post-traumatic headache-related disability and merit an ongoing investigation into their potential as disease markers and treatment targets.

Mild traumatic brain injury affects the features of migraine

BACKGROUND

Headache is one of the most common symptoms after concussion, and mild traumatic brain injury (mTBI) is a risk factor for chronic migraine (CM). However, there remains a paucity of data regarding the impact of mTBI on migraine-related symptoms and clinical course.

METHODS

Of 2161 migraine patients who participated in the American Registry for Migraine Research between February 2016 and March 2020, 1098 completed questions assessing history of TBI (50.8%). Forty-four patients reported a history of moderate to severe TBI, 413 patients reported a history of mTBI. Patients' demographics, headache symptoms and triggers, history of physical abuse, allodynia symptoms (ASC-12), migraine disability (MIDAS), depression (PHQ-2), and anxiety (GAD-7) were compared between migraine groups with (n = 413) and without (n = 641) a history of mTBI. Either the chi-square-test or Fisher's exact test, as appropriate, was used for the analyses of categorical variables. The Mann-Whitney test was used for the analyses of continuous variables. Logistic regression models were used to compare variables of interest while adjusting for age, gender, and CM.

RESULTS

A significantly higher proportion of patients with mTBI had CM (74.3% [307/413] vs. 65.8% [422/641], P = 0.004), had never been married or were divorced (36.6% [147/402] vs. 29.4% [187/636], P = 0.007), self-reported a history of physical abuse (24.3% [84/345] vs. 14.3% [70/491], P <  0.001), had mild to severe anxiety (50.5% [205/406] vs. 41.0% [258/630], P = 0.003), had headache-related vertigo (23.0% [95/413] vs. 15.9% [102/640], P = 0.009), and difficulty finding words (43.0% [174/405] vs. 32.9% [208/633], P <  0.001) in more than half their attacks, and headaches triggered by lack of sleep (39.4% [155/393] vs. 32.6% [198/607], P = 0.018) and reading (6.6% [26/393] vs. 3.0% [18/607], P = 0.016), compared to patients without mTBI. Patients with mTBI had significantly greater ASC-12 scores (median [interquartile range]; 5 [1-9] vs. 4 [1-7], P < 0.001), MIDAS scores (42 [18-85] vs. 34.5 [15-72], P = 0.034), and PHQ-2 scores (1 [0-2] vs. 1 [0-2], P = 0.012).

CONCLUSION

Patients with a history of mTBI are more likely to have a self-reported a history of physical abuse, vertigo, and allodynia during headache attacks, headaches triggered by lack of sleep and reading, greater headache burden and headache disability, and symptoms of anxiety and depression. This study suggests that a history of mTBI is associated with the phenotype, burden, clinical course, and associated comorbid diseases in patients with migraine, and highlights the importance of inquiring about a lifetime history of mTBI in patients being evaluated for migraine.

Post-traumatic headache due to mild traumatic brain injury: Current knowledge and future directions

BACKGROUND/OBJECTIVE

Post-traumatic headache is one of the most common and persistent symptoms following mild traumatic brain injury. The objective of this narrative review is to provide an update on the diagnostic criteria, clinical presentation, epidemiology, pathophysiology, and treatment of post-traumatic headache, and to identify future research priorities.

METHODS

This is a narrative review of the literature regarding post-traumatic headache attributed to mild traumatic brain injury.

RESULTS

Onset of post-traumatic headache within 7 days of injury is the only evidence for a causal relationship between the injury and the headache included in the diagnostic criteria. Post-traumatic headache often resolves within the first few days of onset, whereas it persists for at least 3 months in 30-50%. The majority of insights into post-traumatic headache pathophysiology come from pre-clinical animal studies and human imaging studies, which implicate structural, functional, metabolic, and neuroinflammatory mechanisms for post-traumatic headache. There is a paucity of quality evidence for how to best treat post-traumatic headache.

CONCLUSIONS

Although meaningful progress has been made in the post-traumatic headache field, priorities for future research are numerous, including the optimization of diagnostic criteria, a greater understanding of post-traumatic headache pathophysiology, identifying mechanisms and predictors for post-traumatic headache persistence, and identifying safe, well-tolerated, effective therapies.