Post-traumatic headache attributed to traumatic brain injury: classification, clinical characteristics, and treatment

Rehabilitation of Persistent Symptoms After Concussion

Persistent symptoms following a mild traumatic brain injury are challenging to treat and pose a significant threat to community reintegration. Early recognition and intervention play a pivotal role in preventing the development of persistent symptoms by providing education that emphasizes clear recovery expectations and the high likelihood of full symptom resolution. We recommend early development of a personalized treatment plan, offering guidance on gradual return to activity and specific symptom-targeted treatments that may incorporate both pharmacologic and nonpharmacologic interventions.

Management of Pain and Headache After Traumatic Brain Injury

This article will identify common causes of pain following traumatic brain injury (TBI), discuss current treatment strategies for these complaints, and help tailor treatments for both acute and chronic settings. We will also briefly discuss primary and secondary headache disorders, followed by common secondary pain disorders that may be related to trauma.

American Headache Society white paper on treatment of post-traumatic headache from concussion in youth

OBJECTIVE

To provide healthcare professionals guidance on youth at risk for prolonged recovery and post-traumatic headache (PTH), and on pharmacologic and non-pharmacologic management of PTH due to concussion and mild traumatic brain injury.

BACKGROUND

Headache is the most common persistent post-concussive symptom affecting 8% of youth for >3 months after concussion. Over the past decade, many studies have explored the treatment of PTH in youth, but there are no established guidelines.

METHODS

This white paper is based on a synthesis of an updated systematic review of the literature on treatment of PTH and a narrative review of the literature on risk factors for prolonged recovery and health disparities. Results were interpreted by a group of expert providers in PTH in children and adolescents through collaboration of the PTH and pediatric special interest groups of the American Headache Society.

RESULTS

Factors that consistently were associated with prolonged recovery from concussion and persistent PTH included female sex, a high number of acute symptoms, and adolescent age. Social determinants of health also likely play an important role in PTH and deserve consideration in the clinical and research settings. A total of 33 studies met the criteria for inclusion in the systematic review of PTH treatment in youth, although most were retrospective and of fair-to-poor quality. Treatment strategies included acute and preventive pharmacologic management, procedures, neuro-modulatory devices, physical therapy, physical activity, and behavioral health support. A collaborative care approach that includes a thoughtful combination of these management strategies is likely most effective.

CONCLUSIONS

This white paper provides a roadmap for tailoring the treatment of PTH based on factors influencing prolonged headache, the timing of therapies, and therapies with the most evidence for treating PTH in youth. We also highlight research needed for developing more definitive guidelines on PTH management in youth.

Evaluating the Phenotypic Patterns of Post-Traumatic Headache: A Systematic Review of Military Personnel

INTRODUCTION

Mild traumatic brain injury (TBI) affects a significant number of military personnel, primarily because of physical impact, vehicle incidents, and blast exposure. Post-traumatic headache (PTH) is the most common symptom reported following mild TBI and can persist for several years. However, the current International Classification of Headache Disorders lacks phenotypic characterization for this specific headache disorder. It is important to appropriately classify the headache sub-phenotypes as it may enable more targeted management approaches. This systematic review seeks to identify the most common sub-phenotype of headaches in military personnel with PTH attributed to mild TBI.

METHODS

We conducted a systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines, focusing on the military population. PubMed, Web of Science, Cochrane, and Clinicaltrials.gov databases were searched. Abstracts and full texts were independently reviewed by two authors using predefined inclusion and exclusion criteria. Data extraction was performed using a standardized form. The risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

Eight papers related to the military population were included in this review. Migraine was the most commonly reported headache sub-phenotype, with a prevalence ranging from 33 to 92%. Additionally, one military study identified tension-type headaches as the most prevalent headache phenotype. Although not the primary phenotype, one military cohort reported that approximately one-third of their cohort experienced trigeminal autonomic cephalalgias, which were associated with exposure to blast injuries and prior concussions.

CONCLUSION

This systematic review demonstrated that PTH in the military population frequently exhibit migraine-like features. Tension-type headache and trigeminal autonomic cephalalgias also occur, although less commonly reported. Sub-phenotyping PTH may be important for initiating effective treatment since different phenotypes may respond differently to medications. The study populations analyzed in this systematic review display heterogeneity, underscoring the necessity for additional research features, more stringent criteria and comprehensive recording of baseline characteristics. Characterizing headaches following injury is crucial for an accurate diagnosis to enable effective management and rehabilitation planning for our armed forces.

Connectivity of the insular subdivisions differentiates posttraumatic headache-associated from nonheadache-associated mild traumatic brain injury: an arterial spin labelling study

OBJECTIVE

The insula is an important part of the posttraumatic headache (PTH) attributed to mild traumatic brain injury (mTBI) neuropathological activity pattern. It is composed of functionally different subdivisions and each of which plays different role in PTH neuropathology.

METHODS

Ninety-four mTBI patients were included in this study. Based on perfusion imaging data obtained from arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI), this study evaluated the insular subregion perfusion-based functional connectivity (FC) and its correlation with clinical characteristic parameters in patients with PTH after mTBI and non-headache mTBI patients.

RESULTS

The insular subregions of mTBI + PTH (mTBI patients with PTH) and mTBI-PTH (mTBI patients without PTH) group had positive perfusion-based functional connections with other insular nuclei and adjacent discrete cortical regions. Compared with mTBI-PTH group, significantly increased resting-state perfusion-based FC between the anterior insula (AI) and middle cingulate cortex (MCC)/Rolandic operculum (ROL), between posterior insula (PI) and supplementary motor area (SMA), and decreased perfusion-based FC between PI and thalamus were found in mTBI + PTH group. Changes in the perfusion-based FC of the left posterior insula/dorsal anterior insula with the thalamus/MCC were significant correlated with headache characteristics.

CONCLUSIONS

Our findings provide new ASL-based evidence for changes in the perfusion-based FC of the insular subregion in PTH patients attributed to mTBI and the association with headache features, revealing the possibility of potential neuroplasticity after PTH. These findings may contribute to early diagnosis of the disease and follow-up of disease progression.

Hypersensitivity to BKCa channel opening in persistent post-traumatic headache

BACKGROUND

Large conductance  calcium-activated potassium (BKCa) channels have been implicated in the neurobiological underpinnings of migraine. Considering the clinical similarities between migraine and persistent post-traumatic headache (PPTH), we aimed to examine whether MaxiPost (a BKCa channel opener) could induce migraine-like headache in persons with PPTH.

METHODS

This is a randomized double-blind, placebo-controlled, two-way crossover study from September 2023 to December 2023. Eligible participants were adults with PPTH after mild traumatic brain injury who reported having no personal history of migraine. The randomized participants received a single dose of either MaxiPost (0.05 mg/min) or placebo (isotonic saline) that was infused intravenously over 20 minutes. The two experiment sessions were scheduled at least one week apart to avoid potential carryover effects. The primary endpoint was the induction of migraine-like headache after MaxiPost as compared to placebo within 12 hours of drug administration. The secondary endpoint was the area under the curve (AUC) values for headache intensity scores between MaxiPost and placebo over the same 12-hour observation period.

RESULTS

Twenty-one adult participants (comprising 14 females and 7 males) with PPTH were enrolled and completed both experiment sessions. The proportion of participants who developed migraine-like headache was 11 (52%) of 21 participants after MaxiPost infusion, in contrast to four (19%) participants following placebo (P = .02). Furthermore, the median headache intensity scores, represented by AUC values, were higher following MaxiPost than after placebo (P < .001).

CONCLUSIONS

Our results indicate that BKCa channel opening can elicit migraine-like headache in persons with PPTH. Thus, pharmacologic blockade of BKCa channels might present a novel avenue for drug discovery. Additional investigations are nonetheless needed to confirm these insights and explore the therapeutic prospects of BKCa channel blockers in managing PPTH.

CLINICALTRIALS

GOV IDENTIFIER

NCT05378074.

FNDC5 prevents oxidative stress and neuronal apoptosis after traumatic brain injury through SIRT3-dependent regulation of mitochondrial quality control

Mitochondrial dysfunction and oxidative stress are important mechanisms for secondary injury after traumatic brain injury (TBI), which result in progressive pathophysiological exacerbation. Although the Fibronectin type III domain-containing 5 (FNDC5) was reported to repress oxidative stress by retaining mitochondrial biogenesis and dynamics, its possible role in the secondary injury after TBI remain obscure. In present study, we observed that the level of serum irisin (the cleavage product of FNDC5) significantly correlated with the neurological outcomes of TBI patients. Knockout of FNDC5 increased the lesion volume and exacerbated apoptosis and neurological deficits after TBI in mice, while FNDC5 overexpression yielded a neuroprotective effect. Moreover, FNDC5 deficiency disrupted mitochondrial dynamics and function. Activation of Sirtuin 3 (SIRT3) alleviated FNDC5 deficiency-induced disruption of mitochondrial dynamics and bioenergetics. In neuron-specific SIRT3 knockout mice, FNDC5 failed to attenuate TBI-induced mitochondrial damage and brain injuries. Mechanically, FNDC5 deficiency led to reduced SIRT3 expression via enhanced ubiquitin degradation of transcription factor Nuclear factor erythroid 2-related factor 2 (NRF2), which contributed to the hyperacetylation and inactivation of key regulatory proteins of mitochondrial dynamics and function, including OPA1 and SOD2. Finally, engineered RVG29-conjugated nanoparticles were generated to selectively and efficiently deliver irisin to the brain of mice, which yielded a satisfactory curative effect against TBI. In conclusion, FNDC5/irisin exerts a protective role against acute brain injury by promoting SIRT3-dependent mitochondrial quality control and thus represents a potential target for neuroprotection after TBI.

Serum calcitonin gene-related peptide in patients with persistent post-concussion symptoms, including headache: a cohort study

BACKGROUND

Calcitonin gene-related peptide (CGRP) plays an important role in migraine pathophysiology, and post-traumatic headache (PTH) frequently presents with migraine-like features. Despite several clinical similarities, few studies have explored CGRP in PTH and concussion. This study investigates serum CGRP levels in patients with persistent post-concussion symptoms (PPCS), including PTH.

METHODS

This cohort study was based on serum samples from individuals aged 18-30 years with PPCS who participated in a previously published randomized controlled trial of a non-pharmacological intervention. The primary outcome was serum CGRP concentrations, determined at baseline before randomization and at follow-up 7 months later, using an enzyme-linked immunosorbent assay (ELISA). CGRP levels at baseline were compared with healthy anonymous blood donors in the same age group.

RESULTS

Baseline serum samples were collected from 86 participants with PPCS. The participants were most often female (78%) and migraine-like headache was the most frequent headache phenotype (74%). Serum CGRP levels were higher in participants with PPCS than in 120 healthy individuals (median: 158.5 pg/mL vs. 76.3 pg/mL, p = 0.050). A stratified analysis revealed that females with PPCS had a fivefold higher median than healthy females (166.3 pg/mL vs. 32.1 pg/mL, p = 0.0006), while no differences were observed in males (p = 0.83). At follow-up, CGRP levels decreased with a median change of  - 1.3 pg/mL (95% confidence interval:  - 17.6-0, p = 0.024).

DISCUSSION

Elevated serum levels of CGRP in patients with PPCS and a decrease over time suggest an involvement of CGRP in PTH/PPCS. If confirmed in other studies, it could pave the way for CGRP-targeted therapies, which could have clinical significance.

The Postconcussion Syndrome and Posttraumatic Headaches in Civilians, Soldiers, and Athletes

Posttraumatic headaches are one of the most common and controversial secondary headache types. After a mild traumatic brain, an estimated 11% to 82% of people develop a postconcussion syndrome, which has been controversial for more than 160 years. Headache is estimated as present in 30% to 90% of patients after a mild head injury. Most headaches are tension-type-like or migraine-like. Headaches in civilians, soldiers, athletes, and postcraniotomy are reviewed. The treatments are the same as for the primary headaches. Persistent posttraumatic headaches can continue for many years.

Effects of PDE-3 inhibition in persistent post-traumatic headache: evidence of cAMP-dependent signaling

BACKGROUND

Phosphodiesterase 3 (PDE-3) inhibition have been implicated in the neurobiologic underpinnings of migraine. Considering the clinical similarities between migraine and persistent post-traumatic headache (PPTH), we aimed to ascertain whether PDE-3 inhibition can elicit migraine-like headache in persons with PPTH.

METHODS

We tested cilostazol, which inhibits PDE-3, in a randomized, double-blind, placebo-controlled, two-way crossover study involving persons with PPTH attributed to mild traumatic brain injury. The randomized participants were allocated to receive oral administration of either 200-mg cilostazol or placebo (calcium tablet) on two separate experiment days. The primary end point was the incidence of migraine-like headache during a 12-hour observation window post-ingestion. The secondary endpoint was the area under the curve (AUC) for reported headache intensity scores during the same observation window.

RESULTS

Twenty-one persons underwent randomization and completed both experiment days. The mean participants' age was 41.4 years, and most (n = 17) were females. During the 12-hour observation window, 14 (67%) of 21 participants developed migraine-like headache post-cilostazol, in contrast to three (14%) participants after placebo (P =.003). The headache intensity scores were higher post-cilostazol than after placebo (P <.001).

CONCLUSIONS

Our results provide novel evidence showing that PDE-3 inhibition can elicit migraine-like headache in persons with PPTH. Given that PDE-3 inhibition increases intracellular cAMP levels, our findings allude to the potential therapeutic value of targeting cAMP-dependent signaling pathways in the management of PPTH. Further investigations are imperative to substantiate these insights and delineate the importance of cAMP-dependent signaling pathways in the neurobiologic mechanisms underlying PPTH.

CLINICALTRIALS

GOV IDENTIFIER

NCT05595993.

Hypersensitivity to PACAP-38 in post-traumatic headache: a randomized clinical trial

Pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38), known for its role in migraine pathogenesis, has been identified as a novel drug target. Given the clinical parallels between post-traumatic headache (PTH) and migraine, we explored the possible role of PACAP-38 in the pathogenesis of PTH. To this end, we conducted a randomized, double-blind, placebo-controlled, two-way crossover trial involving adult participants diagnosed with persistent PTH resulting from mild traumatic brain injury. Participants were randomly assigned to receive a 20-min continuous intravenous infusion of either PACAP-38 (10 pmol/kg/min) or placebo (isotonic saline) on two separate experimental days, with a 1-week washout period in between. The primary outcome was the difference in incidence of migraine-like headache between PACAP-38 and placebo during a 12-h observational period post-infusion. The secondary outcome was the difference in the area under the curve (AUC) for baseline-corrected median headache intensity scores during the same 12-h observational period. Of 49 individuals assessed for eligibility, 21 were enrolled and completed the trial. The participants had a mean age of 35.2 years, and 16 (76%) were female. Most [19 of 21 (90%)] had a migraine-like phenotype. During the 12-h observational period, 20 of 21 (95%) participants developed migraine-like headache after intravenous infusion of PACAP-38, compared with two (10%) participants after placebo (P < 0.001). Furthermore, the baseline-corrected AUC values for median headache intensity scores during the 12-h observational period was higher after PACAP-38 than placebo (P < 0.001). These compelling results demonstrate that PACAP-38 is potent inducer of migraine-like headache in people with persistent PTH. Thus, targeting PACAP-38 signalling might be a promising avenue for the treatment of PTH.

Treatment Options for Posttraumatic Headache: A Current Review of the Literature

PURPOSE OF REVIEW

We evaluate evidence-based treatments for posttraumatic headache (PTH), a secondary headache disorder resulting from traumatic brain injury (TBI), comprising nearly 4% of all symptomatic headache disorders. Utilizing recent publications, we aim to inform clinicians of current treatment methods.

RECENT FINDINGS

There is limited research on PTH treatment. A randomized controlled trial (RCT) of metoclopramide with diphenhydramine for acute PTH found that the treatment group (N = 81) experienced more significant pain improvement than placebo by 1.4 points. For persistent PTH, an open-label study of erenumab (N = 89) found that 28% of participants reported ≥ 50% reduction in moderate-to-severe headache days, but an RCT of fremanezumab showed a non-significant reduction in moderate-to-severe headache days. A randomized crossover study of 40 patients with persistent PTH found that onabotulinum toxin-A decreased cumulative number of headaches/week by 43.3% in the treatment group and increased by 35.1% among placebos. In a study of military veterans with severe posttraumatic stress disorder and persistent/delayed onset PTH (N = 193), patients who received Cognitive Behavioral Therapy reported significant improvements in headache-related disability compared to usual care (aggregate mean HIT-6, -3.4). A transcranial magnetic stimulation (N = 24) study found that 58% of participants with mild TBI-related headache experienced a 50% reduction in headache frequency. New studies indicate promise in improving clinically important outcomes of PTH. However, more research is necessary to determine the optimal treatment and whether combining pharmacologic and nonpharmacologic treatment versus a single modality is more effective.

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.

Serial changes in diffusion tensor imaging metrics and therapeutic effects of repetitive transcranial magnetic stimulation in post-traumatic headache and depression: A case report

BACKGROUND

Mild traumatic brain injury patients commonly complain headache and central pain, and the pain accompanies depressive mood change. This case study reports the therapeutic effect of repetitive transcranial magnetic stimulation (rTMS) in mild traumatic brain injury patient with headache and depression through objective serial changes of diffusion tensor imaging (DTI).

METHODS

The 51-year-old man complained of headache and depression despite conventional treatment for 13 months. We applied 15 times rTMS on the left dorsolateral prefrontal cortex. We checked the pain and depression through numeric rating scale (NRS) and Beck depression inventory (BDI) when admission, discharged, and 1 month after discharge. DTI was performed 3 times; before, during-day of rTMS 6th stimulation, and after-day of rTMS 15th stimulation. Then the reconstructed White matter related to pain and depression was obtained.

RESULTS

NRS and BDI showed significant improvement and it was maintained 1 year after discharge. DTI-based metrics of the White matters related to pain and depression gradually increased before - during - after rTMS.

CONCLUSION

Studies focused on examining changes in pain, depression and DTI-based metrics of White matter are rare. This case is significant in that not only pain and depression improved after the rTMS, but also serial changes in White matter were observed in DTI.

Frequency and predictors of headache in the first 12 months after traumatic brain injury: results from CENTER-TBI

BACKGROUND

Headache is a prevalent and debilitating symptom following traumatic brain injury (TBI). Large-scale, prospective cohort studies are needed to establish long-term headache prevalence and associated factors after TBI. This study aimed to assess the frequency and severity of headache after TBI and determine whether sociodemographic factors, injury severity characteristics, and pre- and post-injury comorbidities predicted changes in headache frequency and severity during the first 12 months after injury.

METHODS

A large patient sample from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) prospective observational cohort study was used. Patients were stratified based on their clinical care pathway: admitted to an emergency room (ER), a ward (ADM) or an intensive care unit (ICU) in the acute phase. Headache was assessed using a single item from the Rivermead Post-Concussion Symptoms Questionnaire measured at baseline, 3, 6 and 12 months after injury. Mixed-effect logistic regression analyses were applied to investigate changes in headache frequency and associated predictors.

RESULTS

A total of 2,291 patients responded to the headache item at baseline. At study enrolment, 59.3% of patients reported acute headache, with similar frequencies across all strata. Female patients and those aged up to 40 years reported a higher frequency of headache at baseline compared to males and older adults. The frequency of severe headache was highest in patients admitted to the ICU. The frequency of headache in the ER stratum decreased substantially from baseline to 3 months and remained from 3 to 6 months. Similar trajectory trends were observed in the ICU and ADM strata across 12 months. Younger age, more severe TBI, fatigue, neck pain and vision problems were among the predictors of more severe headache over time. More than 25% of patients experienced headache at 12 months after injury.

CONCLUSIONS

Headache is a common symptom after TBI, especially in female and younger patients. It typically decreases in the first 3 months before stabilising. However, more than a quarter of patients still experienced headache at 12 months after injury. Translational research is needed to advance the clinical decision-making process and improve targeted medical treatment for headache.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02210221.

Inflammation, brain connectivity, and neuromodulation in post-traumatic headache

Post-traumatic headache (PTH) is a debilitating condition that affects individuals with different levels of traumatic brain injury (TBI) severity. The difficulties in developing an effective treatment are related to a lack of understanding the complicated mechanisms and neurobiological changes in brain function after a brain injury. Preclinical studies have indicated that peripheral and central sensitization of the trigeminal nociceptive pathways contributes to PTH. While recent brain imaging studies have uncovered widespread changes in brain functional connectivity following trauma, understanding exactly how these networks contribute to PTH after injury remains unknown. Stimulation of peripheral (trigeminal or vagus) nerves show promising efficacies in PTH experimental animals, likely mediated by influencing TBI-induced pathological plasticity by decreasing neuroinflammation and neuronal apoptosis. Non-invasive brain stimulations, such as transcranial magnetic or direct current stimulations, show analgesia for multiple chronic pain conditions, including PTH. Better mechanistic understanding of analgesia achieved by neuromodulations can define peripheral and central mechanisms involved in the development, the resolution, and the management of PTH.

Advantages of nanocarriers for basic research in the field of traumatic brain injury

A major challenge for the efficient treatment of traumatic brain injury is the need for therapeutic molecules to cross the blood-brain barrier to enter and accumulate in brain tissue. To overcome this problem, researchers have begun to focus on nanocarriers and other brain-targeting drug delivery systems. In this review, we summarize the epidemiology, basic pathophysiology, current clinical treatment, the establishment of models, and the evaluation indicators that are commonly used for traumatic brain injury. We also report the current status of traumatic brain injury when treated with nanocarriers such as liposomes and vesicles. Nanocarriers can overcome a variety of key biological barriers, improve drug bioavailability, increase intracellular penetration and retention time, achieve drug enrichment, control drug release, and achieve brain-targeting drug delivery. However, the application of nanocarriers remains in the basic research stage and has yet to be fully translated to the clinic.

Identification of potential biomarkers and therapeutic targets related to post-traumatic stress disorder due to traumatic brain injury

BACKGROUND

Post-traumatic stress disorder (PTSD), a disease state that has an unclear pathogenesis, imposes a substantial burden on individuals and society. Traumatic brain injury (TBI) is one of the most significant triggers of PTSD. Identifying biomarkers associated with TBI-related PTSD will help researchers to uncover the underlying mechanism that drives disease development. Furthermore, it remains to be confirmed whether different types of traumas share a common mechanism of action.

METHODS

For this study, we screened the eligible data sets from the Gene Expression Omnibus (GEO) database, obtained differentially expressed genes (DEGs) through analysis, conducted functional enrichment analysis on the DEGs in order to understand their molecular mechanisms, constructed a PPI network, used various algorithms to obtain hub genes, and finally evaluated, validated, and analyzed the diagnostic performance of the hub genes.

RESULTS

A total of 430 upregulated and 992 down-regulated differentially expressed genes were extracted from the TBI data set. A total of 1919 upregulated and 851 down-regulated differentially expressed genes were extracted from the PTSD data set. Functional enrichment analysis revealed that the differentially expressed genes had biological functions linked to molecular regulation, cell signaling transduction, cell metabolic regulation, and immune response. After constructing a PPI network and introducing algorithm analysis, the upregulated hub genes were identified as VNN1, SERPINB2, and ETFDH, and the down-regulated hub genes were identified as FLT3LG, DYRK1A, DCN, and FKBP8. In addition, by comparing the data with patients with other types of trauma, it was revealed that PTSD showed different molecular processes that are under the influence of different trauma characteristics and responses.

CONCLUSIONS

By exploring the role of different types of traumas during the pathogenesis of PTSD, its possible molecular mechanisms have been revealed, providing vital information for understanding the complex pathways associated with TBI-related PTSD. The data in this study has important implications for the design and development of new diagnostic and therapeutic methods needed to treat and manage PTSD.

The prevalence of persistent post-traumatic headache in adult civilian traumatic brain injury: a systematic review and meta-analysis on the past 14 years

ABSTRACT

The most recent prevalence estimate of post-traumatic headache (PTH) after traumatic brain injury (TBI) in veterans and civilians dates back to 2008. The prevalence was found to be 57.8%, with surprising higher rates (75.3%) in mild TBI when compared with those with moderate/severe TBI (32.1%). However, the revision of mild TBI diagnostic criteria and an historic peak of TBI in the elderly individuals attributed to the ageing population may lead to different results. Thus, we conducted a systematic review and meta-analysis to assess the updated prevalence of PTH during the past 14 years only in civilians. A literature search was conducted following PRISMA guidelines guided by a librarian. Screening, full-text assessment, data extraction, and risk of bias assessment were performed blindly by 2 raters. Meta-analysis of proportions using the Freeman and Tukey double arcsine method of transformation was conducted. Heterogeneity, sensitivity analysis, and meta-regressions were performed with the predictors: year of publication, mean age, sex, TBI severity, and study design. Sixteen studies were selected for the qualitative analysis and 10 for the meta-analysis. The overall prevalence estimate of PTH was 47.1%, (confidence interval = 34.6, 59.8, prediction intervals = 10.8, 85.4), being similar at different time points (3, 6, 12, and 36+ months). Heterogeneity was high, and none of the meta-regressions were significant. The overall prevalence of PTH after TBI over the past 14 years remains high even if assessed only in civilians. However, the prevalence rates attributed to mild and moderate/severe TBI were similar, differing significantly from previous reports. Efforts are needed to improve TBI outcomes.

Hypersensitivity to opening of ATP-sensitive potassium channels in post-traumatic headache

OBJECTIVE

To investigate whether levcromakalim (a KATP channel opener) induces migraine-like headache in people with persistent post-traumatic headache who had no known history of migraine.

METHODS

In a randomized, double-blind, placebo-controlled, 2-way crossover trial, participants were randomly assigned to receive a 20-minute continuous intravenous infusion of levcromakalim (50 µg/mL) or placebo (isotonic saline) on two separate experimental days with a 1-week wash-out period in between. The primary endpoint was the difference in incidence of migraine-like headache between levcromakalim and placebo during a 12-hour observational period after infusion start. The secondary endpoint was the difference in area under the curve for baseline-corrected median headache intensity scores between levcromakalim and placebo during the 12-hour observational period.

RESULTS

A total of 21 participants with persistent post-traumatic headache were randomized and completed the trial. During the 12-hour observational period, 12 (57%) of 21 participants reported experiencing migraine-like headache following the levcromakalim infusion, compared with three after placebo (P = 0.013). Moreover, the baseline-corrected median headache intensity scores were higher following the levcromakalim infusion than after placebo (P = 0.003).

CONCLUSION

Our findings suggest that KATP channels play an important role in the pathogenesis of migraine-like headache in people with persistent post-traumatic headache. This implies that KATP channel blockers might represent a promising avenue for drug development. Further research is warranted to explore the potential therapeutic benefits of KATP channel blockers in managing post-traumatic headache.Trial Registration: ClinicalTrials.gov Identifier: NCT05243953.

Interdisciplinary rehabilitation for persisting post-concussion symptoms after mTBI: N=15 single case experimental design

BACKGROUND

Despite clinical guidelines recommending an interdisciplinary approach to persisting post-concussion symptom (PPCS) management, evaluations of interdisciplinary interventions remain scant.

OBJECTIVES

This pilot study aimed to explore the feasibility and preliminary efficacy of an interdisciplinary intervention for PPCSs.

METHOD

A single-case experimental design with randomisation to multiple baselines (2, 4, or 6 weeks) was repeated across 15 participants (53% female) with mild traumatic brain injury (mean age 38.3 years, SD 15.7). The 12-week treatment incorporated psychology, physiotherapy, and medical interventions. Feasibility outcomes included recruitment and retention rates, adverse events, treatment adherence and fidelity. Patient-centred secondary outcomes included the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), assessed 3 times per week during the baseline and treatment phases, and at the 1- and 3-month follow-ups. Other secondary outcomes included measures of mood, sleep and fatigue, physical functioning, health-related quality of life, illness perceptions, and goal attainment. Changes in PPCSs were evaluated using systematic visual analysis and Tau-U. Clinically significant changes in secondary outcomes were explored descriptively.

RESULTS

16/26 individuals assessed for eligibility were enroled (61% recruitment rate); 15 completed the post-treatment follow-ups, and 13 completed the 1- and 3-month follow-up assessments (81% retention rate). High treatment adherence and competence in delivering treatments was observed. Moderate-large effect sizes for reducing PPCSs were observed in 12/15 cases, with 7/15 reaching statistical significance. Improvements were maintained at the 1- and 3-month follow-ups and were accompanied by reductions in fatigue, sleep difficulties, and mood symptoms, and changes in illness perceptions. All participants had clinically significant improvements in at least 1 outcome, with 81% of individual therapy goals achieved.

CONCLUSIONS

This pilot study provided preliminary support for a subsequent randomised controlled trial (RCT), with satisfactory recruitment, retention, treatment compliance, and treatment fidelity. Improvement was evident on participant outcomes including symptom reduction and goal attainment, suggesting that progressing to a phase-II RCT is worthwhile. Findings highlight the potential benefit of individualized interdisciplinary treatments.

Effect of Voluntary Exercise on Endogenous Pain Control Systems and Post-traumatic Headache in Mice

Traumatic brain injury (TBI) can cause acute and chronic pain along with motor, cognitive, and emotional problems. Although the mechanisms are poorly understood, previous studies suggest disruptions in endogenous pain modulation may be involved. Voluntary exercise after a TBI has been shown to reduce some consequences of injury including cognitive impairment. We hypothesized, therefore, that voluntary exercise could augment endogenous pain control systems in a rodent model of TBI. For these studies, we used a closed-head impact procedure in male mice modeling mild TBI. We investigated the effect of voluntary exercise on TBI-induced hindpaw nociceptive sensitization, diffuse noxious inhibitory control failure, and periorbital sensitization after bright light stress, a model of post-traumatic headache. Furthermore, we investigated the effects of exercise on memory, circulating markers of brain injury, neuroinflammation, and spinal cord gene expression. We observed that exercise significantly reduced TBI-induced hindpaw allodynia and periorbital allodynia in the first week following TBI. We also showed that exercise improved the deficits associated with diffuse noxious inhibitory control and reduced bright light stress-induced allodynia up to 2 months after TBI. In addition, exercise preserved memory and reduced TBI-induced increases in spinal BDNF, CXCL1, CXCL2, and prodynorphin expression, all genes previously linked to TBI-induced nociceptive sensitization. Taken together, our observations suggest that voluntary exercise may reduce pain after TBI by reducing TBI-induced changes in nociceptive signaling and preserving endogenous pain control systems. PERSPECTIVE: This article evaluates the effects of exercise on pain-related behaviors in a preclinical model of traumatic brain injury (TBI). The findings show that exercise reduces nociceptive sensitization, loss of diffuse noxious inhibitory control, memory deficits, and spinal nociception-related gene expression after TBI. Exercise may reduce or prevent pain after TBI.

Prevalence of and Risk Factors for Post-traumatic Headache in Civilian Patients After Mild Traumatic Brain Injury: A TRACK-TBI Study

OBJECTIVE

To ascertain the prevalence of and risk factors for post-traumatic headache (PTH) attributed to mild traumatic brain injury (mTBI).

PATIENTS AND METHODS

A prospective, longitudinal, multicenter cohort study of patients with mTBI and orthopedic trauma controls who were enrolled from February 26, 2014, to August 8, 2018. The baseline assessment was conducted as soon as possible following evaluation at the emergency department. Follow-ups were scheduled at 2 weeks, 3 months, 6 months, and 12 months postinjury. Eligible patients with mTBI included those 18 years of age or older who presented to the emergency department within 24 hours of head injury warranting evaluation by noncontrast head computed tomography scan. Acute PTH was considered present when a patient reported a headache score of greater than or equal to 2 on the Rivermead Post-concussion Questionnaire at 2 weeks postinjury (ie, headache is at least a mild problem compared with pre-injury). Persistent PTH was defined when a patient with acute PTH reported a Rivermead Post-concussion Questionnaire headache score of greater than or equal to 2 at the scheduled follow-up examinations.

RESULTS

Acute PTH was reported by 963 (60.4%) of 1594 patients with mTBI at 2 weeks postinjury. Among those with acute PTH, 439 (52.4%) of 837 patients reported persistent PTH at 3 months postinjury. This figure decreased over time and 278 (37.5%) of 742 patients continued to report persistent PTH at 6 months, whereas 187 (28.9%) of 646 patients did so as well at 12 months postinjury. Risk factors for acute PTH included younger age, female sex, fewer years of formal education, computed tomography-positive scans, alteration of consciousness, psychiatric history, and history of migraine. Risk factors for persistent PTH included female sex, fewer years of formal education, and history of migraine.

CONCLUSION

Post-traumatic headache is a prevalent sequela of mTBI that persists for at least 12 months in a considerable proportion of affected individuals. The attributable burden necessitates better patient follow-up, disease characterization, improved awareness of PTH in clinical practice, and identification of effective therapies.

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.

Secondary headaches - red and green flags and their significance for diagnostics

A small percentage of patients suffer from a secondary headache syndrome. It is imperative that clinicians are able to differentiate primary headache syndromes from secondary headache syndromes, as failure to do so significantly worsens morbidity and mortality. Recent advances in our understanding of pathobiological mechanisms offer useful information on these enigmatic disorders. We now understand that the causes of secondary headache syndromes can vary significantly - these may be infectious, inflammatory, vascular, traumatic or structural in origin. A well-taken history and targeted physical examination coupled with appropriate investigations can enable these syndromes to be recognized consistently and thus allow their timely and appropriate treatment. Along with their epidemiology, some of their key characteristics shall thus be discussed in this review so as to aid the busy clinician at the bedside. Red flags including sudden onset, high pain intensity, pattern of change of a preexisting headache, focal neurological signs or seizure, systemic signs and precipitation by physical activity can guide the clinician to suspect a secondary headache. Importantly a preexisting headache is not an exclusion of a secondary headache - it might even be a predisposition in certain cases.

Which headache disorders can be diagnosed concurrently? An analysis of ICHD3 criteria using prime encoding system

Introduction

Real-life headache presentations may fit more than one ICHD3 diagnosis. This project seeks to exhaustively list all logically consistent "co-diagnoses" according to the ICHD3 criteria. We limited our project to cases of two concurrent diagnoses.

Methods

We included the criteria for "Migraine" (1.1, 1.2, 1.3), "Tension-type headache" (2.1, 2.2, 2.3, 2.4), "Trigeminal autonomic cephalalgias" (3.1, 3.2, 3.3, 3.4, 3.5), and "Other primary headache disorders." We also excluded "probable" diagnosis criteria. Each characteristic in the above criteria is assigned a unique prime number. We then encoded each ICHD3 criteria into integers through multiplication in a list format; we called these criteria representations. "Codiagnoses representations" were generated by multiplying all possible pairings of criteria representations. We then manually encoded a list of logically inconsistent characteristics through multiplication. All co-diagnoses representations divisible by any inconsistency representations were filtered out, generating a list of co-diagnoses representations that were logically consistent. This list was then translated back into ICHD3 diagnoses.

Results

We used a total of 103 prime numbers to encode 578 ICHD3 criteria. Once illogical characteristics were excluded, we obtained 145 dual diagnoses. Of the dual diagnoses, two contained intersecting characteristics due to subset relationships, 14 contained intersecting characteristics without subset relationships, and 129 contained dual diagnoses as a result of non-intersecting characteristics.

Conclusion

Analysis of dual diagnosis in headaches offers insight into "loopholes" in the ICHD3 as well as a potential explanation for the source of a number of controversies regarding headache disorders. The existence of dual diagnoses and their identification may carry implications for future developments and testing of machine-learning diagnostic algorithms for headaches.

Evaluating Headache and Facial Pain in a Headache Diagnostic Laboratory: Experiences from the Danish Headache Center

BACKGROUND

Diagnostic tests are not routinely used for the diagnosis of primary headaches. It is possible that laboratory tests could be developed and implemented at tertiary headache centers to be an integrated part of the diagnosis and management of headache patients, and laboratory tests that can be used on-site at headache centers could help in evaluating patients with secondary headache disorders.

METHODS

In this narrative review, we present some of the studies that have been made so far at the Headache Diagnostic Laboratory at the Danish Headache Center that aim to investigate and phenotype primary headaches and investigate secondary headaches as well as improve management.

RESULTS

Semi-structured interviews and deep phenotyping, quantitative sensory testing, and provocation studies have been shown to be valuable in categorizing primary and secondary headache subtypes, possible pathophysiology, and defining needs for further research. In patients suspected of increased intracranial pressure, transorbital ultrasound with measurement of the optic sheath diameter may be useful in monitoring patients. The management of headache patients needs to be critically evaluated to optimize treatment continuously.

CONCLUSION

A Headache Diagnostic Laboratory is very useful and should be an integrated part of headache care and management at tertiary headache centers.

Post-Traumatic Craniocervical Disorders From a Postural Control Perspective: A Narrative Review

Mild traumatic brain injury (mTBI) and whiplash injury (WI) may lead to long-term disabling consequences known as post-concussive syndrome (PCS) and whiplash-associated disorders (WADs). PCS and WAD patients commonly complain of conditions encompassing dizziness, vertigo, headache, neck pain, visual complaints, anxiety, and neurocognitive dysfunctions. A proper medical work-up is a priority in order to rule out any acute treatable consequences. However investigations may remain poorly conclusive. Gathered in the head and neck structures, the ocular sensorimotor, the vestibular, and the cervical proprioceptive systems, all involved in postural control, may be damaged by mTBI or WI. Their dysfunctions are associated with a wide range of functional disorders including symptoms reported by PCS and WAD patients. In addition, the stomatognathic system needs to be specifically assessed particularly when associated to WI. Evidence for considering the post-traumatic impairment of these systems in PCS and WAD-related symptoms is still lacking but seems promising. Furthermore, few studies have considered the assessment and/or treatment of these widely interconnected systems from a comprehensive perspective. We argue that further research focusing on consequences of mTBI and WI on the systems involved in the postural control are necessary in order to bring new perspective of treatment.

Post-Traumatic Headache: A Review of Prevalence, Clinical Features, Risk Factors, and Treatment Strategies

Post-traumatic headache (PTH) is a common and debilitating consequence of mild traumatic brain injury (mTBI) that can occur over one year after the head impact event. Thus, better understanding of the underlying pathophysiology and risk factors could facilitate early identification and management of PTH. There are several factors that could influence the reporting of PTH prevalence, including the definition of concussion and PTH. The main risk factors for PTHs include a history of migraines or headaches, female gender, younger age, greater severity of the head injury, and co-occurring psychological symptoms, such as anxiety and depression. PTH clinical profiles vary based on onset, duration, and severity: tension-type headache, migraine headaches, cervicogenic headache, occipital neuralgia, and new daily persistent headache. Pharmacological treatments often consist of analgesics and non-steroidal anti-inflammatory drugs, tricyclic antidepressants, or antiepileptic medication. Cognitive behavioral therapy, relaxation techniques, biofeedback, and physical therapy could also be used for PTH treatment. Our work highlighted the need for more rigorous studies to better describe the importance of identifying risk factors and patient-centered treatments and to evaluate the effectiveness of the existing treatment options. Clinicians should consider a multidisciplinary approach to managing PTH, including pharmacotherapy, cognitive behavioral therapy, and lifestyle changes.

Self-healing hydrogel as an injectable implant: translation in brain diseases

Tissue engineering biomaterials are aimed to mimic natural tissue and promote new tissue formation for the treatment of impaired or diseased tissues. Highly porous biomaterial scaffolds are often used to carry cells or drugs to regenerate tissue-like structures. Meanwhile, self-healing hydrogel as a category of smart soft hydrogel with the ability to automatically repair its own structure after damage has been developed for various applications through designs of dynamic crosslinking networks. Due to flexibility, biocompatibility, and ease of functionalization, self-healing hydrogel has great potential in regenerative medicine, especially in restoring the structure and function of impaired neural tissue. Recent researchers have developed self-healing hydrogel as drug/cell carriers or tissue support matrices for targeted injection via minimally invasive surgery, which has become a promising strategy in treating brain diseases. In this review, the development history of self-healing hydrogel for biomedical applications and the design strategies according to different crosslinking (gel formation) mechanisms are summarized. The current therapeutic progress of self-healing hydrogels for brain diseases is described as well, with an emphasis on the potential therapeutic applications validated by in vivo experiments. The most recent aspect as well as the design rationale of self-healing hydrogel for different brain diseases is also addressed.

Evaluation of temporomandibular joint dysfunction in traumatic brain injury patients

BACKGROUND

The aim of this study was to evaluate the frequency of temporomandibular joint dysfunction and related factors in patients with traumatic brain injury.

METHODS

A total of 60 participants, 30 patients with traumatic brain injury and 30 healthy volunteers of similar age, have been included in this study, which was designed as a hospital-based cross sectional study. Fonseca questionnaire was used to evaluate and classify the temporomandibular joint dysfunction. Temporomandibular joint range of motion was evaluated with a digital calliper, and masticatory muscles pressure pain threshold was evaluated with an algometer. Labial commissure angle measurement was used to evaluate the severity of facial paralysis. Complications related to traumatic brain injury were recorded in patients with traumatic brain injury.

RESULTS

According to Fonseca questionnaire score, 80% of traumatic brain injury patients and 16.7% of the control group had temporomandibular dysfunction (p < .001). In the intergroup comparison, a significant decrease was found in all temporomandibular range of motion and masticatory muscles pressure pain threshold parameters in favour of the traumatic brain injury group (p < .001). Labial commissure angle and Fonseca questionnaire scores were higher in the traumatic brain injury group (p < .001). The frequency of temporomandibular dysfunction was more common in traumatic brain injury patients with headache than in those without headache, as shown by the results of the Fonseca questionnaire (p = .044).

CONCLUSION

Compared to healthy controls, patients with traumatic brain injury experienced issues with the temporomandibular joint more frequently. Additionally, TBI patients with headaches had a greater frequency of temporomandibular joint dysfunction. Therefore, it is advised to check for temporomandibular joint dysfunction in traumatic brain injury patients during follow-up. In addition, the presence of headache in traumatic brain injury patients may be a stimulant for temporomandibular joint dysfunction.

White matter hyperintensities and cerebral microbleeds in persistent post-traumatic headache attributed to mild traumatic brain injury: a magnetic resonance imaging study

OBJECTIVE

To examine whether white matter hyperintensities (WMHs) and cerebral microbleeds (CMBs) are more prevalent in people with persistent post-traumatic headache attributed to mild traumatic brain injury (TBI), compared with healthy controls.

METHODS

A magnetic resonance imaging (MRI) study of adults with persistent post-traumatic headache attributed to mild TBI and age- and gender-matched healthy controls. A semi-structured interview and validated self-report instruments were used to record data on demographics, clinical characteristics, and comorbidities. Imaging data were obtained on a 3T MRI Scanner using a 32-channel head coil. Participants and controls underwent a single MRI session, in which fluid-attenuated inversion recovery was used to visualize WMHs, and susceptibility-weighted imaging was used to detect CMBs. The primary outcomes were (I) the difference in the mean number of WMHs between participants with persistent post-traumatic headache and healthy controls and (II) the difference in the mean number of CMBs between participants with persistent post-traumatic headache and healthy controls. All images were examined by a certified neuroradiologist who was blinded to the group status of the participants and controls.

RESULTS

A total of 97 participants with persistent post-traumatic headache and 96 age- and gender-matched healthy controls provided imaging data eligible for analyses. Among 97 participants with persistent post-traumatic headache, 43 (44.3%) participants presented with ≥ 1 WMH, and 3 (3.1%) participants presented with ≥ 1 CMB. Compared with controls, no differences were found in the mean number of WMHs (2.7 vs. 2.1, P = 0.58) and the mean number of CMBs (0.03 vs. 0.04, P = 0.98).

CONCLUSIONS

WMHs and CMBs were not more prevalent in people with persistent post-traumatic headache than observed in healthy controls. Future studies should focus on other MRI techniques to identify radiologic biomarkers of post-traumatic headache.

Comparison of continuous headache features in youth with migraine, new daily persistent headache, and persistent post-traumatic headache

OBJECTIVE

To compare clinical features in youth with continuous headache from migraine, persistent post-traumatic headache, and new daily persistent headache to determine if they are similar, contrary to their distinction in the International Classification of Headache Disorders.

METHODS

We pursued a single center age- and sex-matched observational study comparing the clinical characteristics of 150 youth (11 - 17 years old) with continuous headache from migraine, persistent post-traumatic headache, and new daily persistent headache. A diagnostic algorithm based on international classification of headache disorders criteria was used to identify those with migraine (headache features of migraine with gradual onset), and persistent post-traumatic headache and new daily persistent headache (based on the circumstances of headache onset regardless of headache features). Fifty participants each with migraine, persistent post-traumatic headache, and new daily persistent headache were matched by age and sex. Participant survey responses on headache characteristics were compared.

RESULTS

Median usual headache severity was 6.0 [95%CI 6.0, 6.0] and was not different across diagnostic groups (H statistic = 1.2, p = 0.55). Headache exacerbation frequency, disability, associated symptoms, and most triggers were not significantly different across groups. The majority of persistent post-traumatic headache and new daily persistent headache had headache features consistent with a diagnose of migraine (72% and 62%, respectively).

CONCLUSION

Our findings suggest that most persistent post-traumatic headache and new daily persistent headache may represent abrupt onset of migraine.

Preclinical Studies of Posttraumatic Headache and the Potential Therapeutics

Posttraumatic headache (PTH) attributed to traumatic brain injury (TBI) is a secondary headache developed within 7 days after head injury, and in a substantial number of patients PTH becomes chronic and lasts for more than 3 months. Current medications are almost entirely relied on the treatment of primary headache such as migraine, due to its migraine-like phenotype and the limited understanding on the PTH pathogenic mechanisms. To this end, increasing preclinical studies have been conducted in the last decade. We focus in this review on the trigeminovascular system from the animal studies since it provides the primary nociceptive sensory afferents innervating the head and face region, and the pathological changes in the trigeminal pathway are thought to play a key role in the development of PTH. In addition to the pathologies, PTH-like behaviors induced by TBI and further exacerbated by nitroglycerin, a general headache inducer through vasodilation are reviewed. We will overview the current pharmacotherapies including calcitonin gene-related peptide (CGRP) monoclonal antibody and sumatriptan in the PTH animal models. Given that modulation of the endocannabinoid (eCB) system has been well-documented in the treatment of migraine and TBI, the therapeutic potential of eCB in PTH will also be discussed.

A Single Episode of Cortical Spreading Depolarization Increases mRNA Levels of Proinflammatory Cytokines, Calcitonin Gene-Related Peptide and Pannexin-1 Channels in the Cerebral Cortex

Cortical spreading depolarization (CSD) is the neuronal correlate of migraine aura and the reliable consequence of acute brain injury. The role of CSD in triggering headaches that follow migraine aura and brain injury remains to be uncertain. We examined whether a single CSD occurring in awake animals modified the expression of proinflammatory cytokines (Il1b, TNF, and Il6) and endogenous mediators of nociception/neuroinflammation-pannexin 1 (Panx1) channel and calcitonin gene-related peptide (CGRP), transforming growth factor beta (TGFb) in the cortex. Unilateral microinjury of the somatosensory cortex triggering a single CSD was produced in awake Wistar rats. Three hours later, tissue samples from the lesioned cortex, intact ipsilesional cortex invaded by CSD, and homologous areas of the contralateral sham-treated cortex were harvested and analyzed using qPCR. Three hours post-injury, intact CSD-exposed cortexes increased TNF, Il1b, Panx1, and CGRP mRNA levels. The strongest upregulation of proinflammatory cytokines was observed at the injury site, while CGRP and Panx1 were upregulated more strongly in the intact cortexes invaded by CSD. A single CSD is sufficient to produce low-grade parenchymal neuroinflammation with simultaneous overexpression of Panx1 and CGRP. The CSD-induced molecular changes may contribute to pathogenic mechanisms of migraine pain and post-injury headache.

3D printing of injury-preconditioned secretome/collagen/heparan sulfate scaffolds for neurological recovery after traumatic brain injury in rats

BACKGROUND

The effects of traumatic brain injury (TBI) can include physical disability and even death. The development of effective therapies to promote neurological recovery is still a challenging problem. 3D-printed biomaterials are considered to have a promising future in TBI repair. The injury-preconditioned secretome derived from human umbilical cord blood mesenchymal stem cells showed better stability in neurological recovery after TBI. Therefore, it is reasonable to assume that a biological scaffold loaded with an injury-preconditioned secretome could facilitate neural network reconstruction after TBI.

METHODS

In this study, we fabricated injury-preconditioned secretome/collagen/heparan sulfate scaffolds by 3D printing. The scaffold structure and porosity were examined by scanning electron microscopy and HE staining. The cytocompatibility of the scaffolds was characterized by MTT analysis, HE staining and electron microscopy. The modified Neurological Severity Score (mNSS), Morris water maze (MWM), and motor evoked potential (MEP) were used to examine the recovery of cognitive and locomotor function after TBI in rats. HE staining, silver staining, Nissl staining, immunofluorescence, and transmission electron microscopy were used to detect the reconstruction of neural structures and pathophysiological processes. The biocompatibility of the scaffolds in vivo was characterized by tolerance exposure and liver/kidney function assays.

RESULTS

The excellent mechanical and porosity characteristics of the composite scaffold allowed it to efficiently regulate the secretome release rate. MTT and cell adhesion assays demonstrated that the scaffold loaded with the injury-preconditioned secretome (3D-CH-IB-ST) had better cytocompatibility than that loaded with the normal secretome (3D-CH-ST). In the rat TBI model, cognitive and locomotor function including mNSS, MWM, and MEP clearly improved when the scaffold was transplanted into the damage site. There is a significant improvement in nerve tissue at the site of lesion. More abundant endogenous neurons with nerve fibers, synaptic structures, and myelin sheaths were observed in the 3D-CH-IB-ST group. Furthermore, the apoptotic response and neuroinflammation were significantly reduced and functional vessels were observed at the injury site. Good exposure tolerance in vivo demonstrated favorable biocompatibility of the scaffold.

CONCLUSIONS

Our results demonstrated that injury-preconditioned secretome/collagen/heparan sulfate scaffolds fabricated by 3D printing promoted neurological recovery after TBI by reconstructing neural networks, suggesting that the implantation of the scaffolds could be a novel way to alleviate brain damage following TBI.

Debate: Are cluster headache and migraine distinct headache disorders?

Cluster headache and migraine are regarded as distinct primary headaches. While cluster headache and migraine differ in multiple aspects such as gender-related and headache specific features (e.g., attack duration and frequency), both show clinical similarities in trigger factors (e.g., alcohol) and treatment response (e.g., triptans). Here, we review the similarities and differences in anatomy and pathophysiology that underlie cluster headache and migraine, discuss whether cluster headache and migraine should indeed be considered as two distinct primary headaches, and propose recommendations for future studies. Video recording of the debate held at the 1st International Conference on Advances in Migraine Sciences (ICAMS 2022, Copenhagen, Denmark) is available at https://www.youtube.com/watch?v=uUimmnDVTTE .

CGRP-induced migraine-like headache in persistent post-traumatic headache attributed to mild traumatic brain injury

OBJECTIVE

To ascertain whether intravenous infusion of calcitonin gene-related peptide (CGRP) can induce migraine-like headache in people with persistent post-traumatic headache attributed to mild traumatic brain injury (TBI) and no pre-existing migraine.

METHODS

A non-randomized, single-arm, open-label study at a single site in Denmark. Eligible participants were aged 18 to 65 years and had a known history of persistent post-traumatic headache attributed to mild TBI for ≥ 12 months. All participants received continuous intravenous infusion of CGRP (1.5 µg/min) over 20 min. A headache diary was used to collect outcome data until 12 h after the start of CGRP infusion. The primary end point was the incidence of migraine-like headache during 12-hour observational period.

RESULTS

A total of 60 participants completed the study protocol and provided data for the analysis of the primary end point. The median age was 32.5 (IQR, 25.5-43.0) years; 43 participants (72%) were female. Following CGRP infusion, 43 (72%) of 60 participants developed migraine-like headache during the 12-hour observational period. The median time to peak headache intensity was 40 min (IQR, 20-60), and the median peak headache intensity was 6 (IQR, 5-8) on the 11-point numeric rating scale.

CONCLUSION

Intravenous infusion of CGRP is a potent inducer of migraine-like headache in people with persistent post-traumatic headache attributed to mild TBI. This observation underscores the importance of CGRP in the genesis of migraine-like headache that is often experienced by individuals who are afflicted by persistent post-traumatic headache. Further research is warranted to ascertain whether other signaling molecules also contribute to the disease mechanisms underlying post-traumatic headache.

Total tenderness score and pressure pain thresholds in persistent post-traumatic headache attributed to mild traumatic brain injury

Objective

To investigate whether persistent post-traumatic headache attributed to mild traumatic brain injury (TBI) is associated with more pronounced pericranial tenderness and lower pressure pain thresholds (PPTs) in the head and neck region, compared with healthy controls.

Methods

Patients with persistent post-traumatic headache (n = 100) and age- and gender-matched healthy controls (n = 100) were included between July 2018 and June 2019. Total tenderness score (TTS) was used to assess pericranial tenderness by bilateral manual palpation in eight muscles or tendon insertions. Summation was then used to calculate a TTS from 0 to 48 based on individual right- and left-sided scores; higher TTS score indicated more pronounced pericranial tenderness. PPTs were examined in m. temporalis and m. trapezius (upper and middle part) using an electronic pressure algometer that applies increasing blunt pressure at a constant rate.

Results

The TTS score was higher in patients with persistent post-traumatic headache (median, 21; IQR, 12–31), compared with healthy controls (median, 10; IQR, 6–17; P < .001). PPTs were lower in patients with persistent post-traumatic headache than in controls in both the left-sided m. temporalis (mean ± SD, 157.5 ± 59.9 vs. 201.1 ± 65.2; P < .001) and right-sided m. temporalis (mean ± SD, 159.5 ± 63.8 vs. 212.3 ± 61.9; P < .001). Furthermore, patients with persistent post-traumatic headache also had lower left- and right-sided PPTs in the upper as well as middle part of m. trapezius, compared with healthy controls; all P values were .05 or less.

Conclusions

Among patients with persistent post-traumatic headache, pericranial tenderness was more pronounced and PPTs in the head and neck region were lower than in healthy controls free of headache and mild TBI. Further research is needed to better understand the involvement of pericranial myofascial nociceptors in the disease mechanisms underlying post-traumatic headache.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01457-1.

Observations from a prospective small cohort study suggest that CGRP genes contribute to acute posttraumatic headache burden after concussion

Introduction

Post-traumatic headache (PTH) is commonly reported after concussion. Calcitonin gene-related peptide (CGRP) is implicated in the pathogenesis of migraine. We explored how single nucleotide polymorphisms (SNPs) from CGRP-alpha (CALCA) and the receptor activity modifying protein-1 (RAMP1) related to headache burden during the first week after concussion.

Methods

A prospective study was performed in 34 collegiate athletes who sustained a concussion. Participants completed the symptom evaluation checklist from the SCAT3 within 48 h of injury (V1), and again 4 (V2) and 7 (V3) days after injury. For each visit, the self-reported score (0–6) for headache, pressure in head, blurred vision, and sensitivity to light/noise were reported and summed to calculate the headache burden. A saliva sample was obtained and genotyped for CALCA (rs3781719) and RAMP1 (rs10185142). RAMP1 (TT, TC, CC) and CALCA (AA, AG, GG) were dichotomized (A+, A- and T+, T-, respectively), and concatenated (T+A+, T+A-, T-A+, T-A-) for analyses.

Results

Headache Burden at Visit 1 was greatest in T+A+ compared to T-A+, and trended toward a significant difference with T+A-. Repeated-measures ANOVA revealed the presence of significant visit main effects (p &lt; 0.001, η2 = 0.404), but the group (p = 0.055) and interaction effects only trended (p = 0.094). Pearson's χ2-tests revealed that 88% of those with return-to play (RTP) exclusions ≥15 days had PTH with multi-sensory symptoms (PTH+SENS) as compared to 35% in those with RTP &lt; 14 day.

Conclusion

Knowledge of RAMP1 and CALCA genotypes appear to improve an understanding the presenting features and magnitude of headache burden after concussion injury.

Applications and Mechanisms of Stimuli-Responsive Hydrogels in Traumatic Brain Injury

Traumatic brain injury (TBI) is a global neurotrauma with high morbidity and mortality that seriously threatens the life quality of patients and causes heavy burdens to families, healthcare institutions, and society. Neuroinflammation and oxidative stress can further aggravate neuronal cell death, hinder functional recovery, and lead to secondary brain injury. In addition, the blood–brain barrier prevents drugs from entering the brain tissue, which is not conducive to the recovery of TBI. Due to their high water content, biodegradability, and similarity to the natural extracellular matrix (ECM), hydrogels are widely used for the delivery and release of various therapeutic agents (drugs, natural extracts, and cells, etc.) that exhibit beneficial therapeutic efficacy in tissue repair, such as TBI. Stimuli-responsive hydrogels can undergo reversible or irreversible changes in properties, structures, and functions in response to internal/external stimuli or physiological/pathological environmental stimuli, and further improve the therapeutic effects on diseases. In this paper, we reviewed the common types of stimuli-responsive hydrogels and their applications in TBI, and further analyzed the therapeutic effects of hydrogels in TBI, such as pro-neurogenesis, anti-inflammatory, anti-apoptosis, anti-oxidation, and pro-angiogenesis. Our study may provide strategies for the treatment of TBI by using stimuli-responsive hydrogels.

Treatment and Rehabilitation for Traumatic Brain Injury: Current Update

Traumatic brain injury (TBI) is an acquired injury to the brain caused by external mechanical forces, which can cause temporary or permanent disability. TBI and its potential long-term consequences are serious public health concerns. This review seeks to provide updated information on the current methods of management of patients with TBI to improve patient care.

Reframing postconcussional syndrome as an interface disorder of neurology, psychiatry and psychology

Persistent symptoms following a minor head injury can cause significant morbidity, yet the underlying mechanisms for this are poorly understood. The shortcomings of the current terminology that refer to non-specific symptom clusters is discussed. This update considers the need for a multi-dimensional approach for the heterogenous mechanisms driving persistent symptoms after mild traumatic brain injury. Relevant pathophysiology is discussed to make the case for mild traumatic brain injury to be conceptualized as an interface disorder spanning neurology, psychiatry and psychology. The relevance of pre-injury factors, psychological co-morbidities and their interaction with the injury to produce persistent symptoms are reviewed. The interplay with psychiatric diagnoses, functional and somatic symptom disorder presentations and the influence of the medicolegal process is considered. The judicious use and interpretation of investigations given the above complexity is discussed, with suggestions of how the explanation of the diagnostic formulation to the patient can be tailored, including insight into the above processes, to aid recovery. Moving beyond the one-dimensional concept of 'postconcussional syndrome' and reframing the cause of persistent symptoms following mild traumatic brain injury in a bio-psycho-socio-ecological model will hopefully improve understanding of the underlying contributory mechanistic interactions and facilitate treatment.

Equity and Disparities in Diagnosis, Management, and Research of Post-Traumatic Headache

PURPOSE OF REVIEW

There are notable health disparities and inequities in individuals with traumatic brain injury (TBI) and concussion by race, ethnicity, gender, socioeconomic status, and geography. This review will evaluate these disparities and inequities and assess the social determinants of health that drive outcomes for post-traumatic headache. Interventions for achieving this are also discussed.

RECENT FINDINGS

Significant disparities and inequities exist in TBI and concussion among people of different races, socioeconomic status, and geographic locations. Migraine is a common symptom post-concussion, for which disparities and social determinants of health are also discussed. Overall, multi-level interventions to reduce these disparities and inequities are reviewed for post-traumatic headache but require further investigation. Interventions are needed to reduce disparities and inequities including public health initiatives, improvements in clinical care, diversity/inclusion training, and research efforts. As literature expands, we can form guidance to identify solutions for eliminating disparities in care of diverse populations.

Brain Extract of Subacute Traumatic Brain Injury Promotes the Neuronal Differentiation of Human Neural Stem Cells via Autophagy

Background: After a traumatic brain injury (TBI), the cell environment is dramatically changed, which has various influences on grafted neural stem cells (NSCs). At present, these influences on NSCs have not been fully elucidated, which hinders the finding of an optimal timepoint for NSC transplantation. Methods: Brain extracts of TBI mice were used in vitro to simulate the different phase TBI influences on the differentiation of human NSCs. Protein profiles of brain extracts were analyzed. Neuronal differentiation and the activation of autophagy and the WNT/CTNNB pathway were detected after brain extract treatment. Results: Under subacute TBI brain extract conditions, the neuronal differentiation of hNSCs was significantly higher than that under acute brain extract conditions. The autophagy flux and WNT/CTNNB pathway were activated more highly within the subacute brain extract than in the acute brain extract. Autophagy activation by rapamycin could rescue the neuronal differentiation of hNSCs within acute TBI brain extract. Conclusions: The subacute phase around 7 days after TBI in mice could be a candidate timepoint to encourage more neuronal differentiation after transplantation. The autophagy flux played a critical role in regulating neuronal differentiation of hNSCs and could serve as a potential target to improve the efficacy of transplantation in the early phase.

Preclinical assessment of onabotulinumtoxinA for the treatment of mild traumatic brain injury-related acute and persistent post-traumatic headache

Objective

Investigation of onabotulinumtoxinA in a murine model of acute and persistent post-traumatic headache.

Methods

Mild traumatic brain injury was induced with a weight drop method. Periorbital and hindpaw cutaneous allodynia were measured for 14 days. Mice were then exposed to bright light stress and allodynia was reassessed. OnabotulinumtoxinA (0.5 U) was injected subcutaneously over the cranial sutures at different post-injury time points.

Results

After milt traumatic brain injury, mice exhibited periorbital and hindpaw allodynia that lasted for approximately 14 days. Allodynia could be reinstated on days 14–67 by exposure to stress only in previously injured mice. OnabotulinumtoxinA administration at 2 h after mild traumatic brain injury fully blocked both transient acute and stress-induced allodynia up to day 67. When administered 72 h post-mild traumatic brain injury, onabotulinumtoxinA reversed acute allodynia, but only partially prevented stress-induced allodynia. OnabotulinumtoxinA administration at day 12, when initial allodynia was largely resolved, produced incomplete and transient prevention of stress-induced allodynia. The degree of acute allodynia correlated positively with subsequent stress-induced allodynia.

Conclusion

Mild traumatic brain injury induced transient headache-like pain followed by long lasting sensitization and persistent vulnerability to a normally innocuous stress stimulus, respectively modeling acute and persistent post-traumatic headache.. Administration of onabotulinumtoxinA following the resolution of acute post-traumatic headache diminished persistent post-traumatic headache but the effects were transient, suggesting that underlying persistent mild traumatic brain injury-induced maladaptations were not reversed. In contrast, early onabotulinumtoxinA administration fully blocked both acute post-traumatic headache as well as the transition to persistent post-traumatic headache suggesting prevention of neural adaptations that promote vulnerability to headache-like pain. Additionally, the degree of acute post-traumatic headache was predictive of risk of persistent post-traumatic headache.

Post-traumatic headache: Pathophysiology and management - A review

Background

Post-traumatic headache (PTH) is a common secondary headache due to traumatic brain injury. In the past, significant research has been conducted to understand the pathophysiology and treatment options for PTH. However, PTH still lacks evidence-based treatment, and most of the management depends on the primary phenotype observed in the patient.

Objective

The main objective of this review is to provide a single reference that covers the current understanding of the pathophysiology and the treatment options available for PTH.

Methods

A detailed literature search on PubMed was performed, and a narrative review was prepared.

Results

The pathophysiology of PTH is multifactorial. Acute PTH may be attributed to increased peripheral pain sensitization with impaired pain inhibiting pathways. Chronic or persistent PTH may be due to a chronic inflammatory response and peripheral as well as central sensitization. The mechanism responsible for the transition of acute to persistent PTH is unknown. The migraine-like phenotype is reported to be the most prevalent headache type seen in PTH. New targets for preventive treatment have been identified in recent years, such as neuropeptides like calcitonin-gene-related peptide (CGRP), nitric oxide, and glutamate. The preventive pharmacological and non-pharmacological strategies employed for migraine (e.g. anti-CGRP monoclonal antibodies, onabotulinumtoxinA, physical therapy, cognitive and behavioral treatment, and neurostimulation techniques) have shown in preliminary studies that they are potentially efficacious, but large, randomized, double blind, placebo controlled trials are needed to further establish these as treatment options for PTH.

Conclusions

The lack of evidence-based treatment for PTH has created a need for future large trials to confirm the safety and efficacy of the currently employed treatments.

Effects of acupuncture treatment on posttraumatic headache after traumatic brain injury in patients: A protocol for systematic review

BACKGROUND

Posttraumatic headache (PTH) after traumatic brain injury (TBI) is a common clinical symptom, which refers to a headache that occurs after TBI. Acupuncture is often used for the treatment of such patients in China, and significant clinical effects have been achieved. However, to date, its efficacy has not been methodically evaluated. The purpose of this systematic review is to provide evidence to prove the effectiveness of acupuncture in the treatment of PTH in patients with TBI.

METHODS

This systematic review will be conducted in accordance with the preferred reporting items for systematic review and meta-analysis protocols. The following electronic databases will be searched from their inception to February 2022: PubMed, Web of Science, Embase, PsycINFO, the Cochrane Library, and Chinese databases such as Chinese Biomedical Literature (CBM), Chinese Medical Current Content (CMCC), Chinese Scientific Journal Database (VIP), WanFang Database, and China National Knowledge Infrastructure (CNKI). No language restrictions will be applied to the search strategy. Randomized controlled trials and cohort and case-control studies that met the inclusion and exclusion criteria will be included in this study. The meta-analysis will be performed using RevMan 5.3 software. Each session of this systematic review will be conducted independently by 2 members.

RESULTS

This review evaluates the efficacy of acupuncture in the treatment of PTH after TBI.

CONCLUSION

This review provides substantial evidence for the clinical application of acupuncture in PTH treatment after TBI.

ETHICS AND DISSEMINATION

Since the data in this study will be retrieved from published trials, therefore the Patient Consent Statement and Ethical Approval are not required. We will disseminate our results by publishing the research in a peer-reviewed journal.

TRAIL REGISTRATION NUMBER

The protocol was registered in INPLASY (INPLASY 202220073).

Barriers and gaps in headache education: a national cross-sectional survey of neurology residents in Denmark

BACKGROUND

A major barrier to adequate headache care is the relative lack of formal education and training of healthcare professionals. Concerted efforts should be made to pinpoint major gaps in knowledge in healthcare professionals to facilitate better educational policies in headache training. The aim of this study was to identify deficiencies and barriers in headache training among residents in neurology in Denmark.

METHODS

We conducted a national cross-sectional survey of residents in neurology in Denmark from April 2019 to September 2019. The survey included questions on participant demographics, knowledge of and barriers in headache disorders, guidelines and diagnostic tools usage, contact with primary and tertiary care, medication overuse, and non-pharmacological interventions. Furthermore, respondents were asked to provide a ranked list from most to least interesting for six sub-specializations/disorders, i.e., cerebrovascular disease, dementia, epilepsy, headache, multiple sclerosis, Parkinson's disease.

RESULTS

Sixty (40%) out of estimated a population of ~ 150 resident across Denmark accepted the invitation. Of these, 54/60 (90%) completed the survey. Although two-thirds, 35/54 (65%), of the respondents had prior formalized training in headache disorders, we identified gaps in all explored domains including diagnosis, management, and referral patterns. Particularly, there was an inconsistent use of guidelines and diagnostic criteria from the Danish Headache Society (2.74 (± 1.14)), the Danish Neurological Society (3.15 (± 0.86)), and the International Classification of Headache Disorders (2.33 (± 1.08)); 1: never/have not heard of, 4: always. Headache was ranked second to last out of six sub-specializations in interest.

CONCLUSIONS

Overall knowledge on headache disorders amongst neurology residents in Denmark do not meet the expectations set out by national and international recommendations. Stakeholders should make strategic initiatives for structured education in headache for improved clinical outcomes in parallel with costs reduction through resource optimization.