Prevalence and treatment of headaches in veterans with mild traumatic brain injury

Characteristics of men and women with medically diagnosed cluster headache in a national integrated healthcare system: A Veterans Health Administration cohort study

OBJECTIVE

Describe the epidemiology of cluster headache (CH) using Veterans Health Administration (VHA) Electronic Health Record (EHR) data.

BACKGROUND

Epidemiologic studies of CH at the population level are difficult because it has a prevalence of ~0.1%. Hospital system-wide studies are an attractive alternative as they have large numbers of patients and broader populations than headache or neurology clinic-based studies. The VHA is an ideal hospital-based system in which to study CH because it is nationwide, predominantly male, has a strong focus on mood disorders and suicidality, and has accessible individual medical records. Here, we report the first headache study based on an ongoing longitudinal cohort of patients with CH using VHA EHR data.

METHODS

The VHA EHR data were accessed from Fiscal Year 2008 to 2019. Patients with CH consisted of all patients with at least one outpatient visit containing a CH diagnosis code from the International Classification of Diseases (ICD)-9 or -10. We extracted data on demographic features, incidence, and prevalence, as well as pain and psychiatric comorbidities.

RESULTS

Of the 1,524,960 distinct patients who presented for headache treatment in the VHA between Fiscal Year 2008-2019, 24,131 had at least one visit with a CH diagnosis. The 1-year period prevalence of a CH diagnosis in the VHA ranges from 0.08% to 0.10% for women and 0.10% to 0.18% for men. A larger proportion of women versus men received a diagnosis of unspecified CH (59.6% [1412/2368] vs. 53.6% [11,663/21,763], p < 0.001). Most patients with CH had both comorbid headache and non-headache pain diagnoses. Headache not-otherwise-specified was the most common comorbid headache disorder at 70.0% (16,885/24,131) and was more common in women (76.1%, 1801/2368) compared to men (69.3%, 15,084/21,763). Other common comorbidities included migraine, depression, tobacco use, and obstructive sleep apnea. Rates of suicidal ideation or attempt were almost 50% higher in women (5-year proportion 9.4%, 222/2368) with CH compared to men (6.6%, 1433/21,763).

CONCLUSIONS

To our knowledge this is the largest hospital system study of CH to date and reinforces several previous studies. Pain, mental health, and sleep disorders comorbidities are particularly prevalent in this group and were often more common in women compared to men with CH. Future work should examine gender and race stratified prevalence estimates within the VHA and other healthcare systems.

Physical Health and Well-being: Updates and the Way Ahead

INTRODUCTION

The Women in Combat Summit 2021 "Forging the Future: How Women Enhance the Fighting Force" took place during February 9-11, 2021, via a virtual conference platform. The third and final day of the Summit regarded the physical health and well-being of military women and included the topics of urogenital health, nutrition and iron-deficiency anemia, unintended pregnancy and contraception, and traumatic brain injury.

MATERIALS AND METHODS

After presentations on the topics earlier, interested conference attendees were invited to participate in focus groups to discuss and review policy recommendations for physical health and well-being in military women. Discussions centered around the topics discussed during the presentations, and suggestions for future Women in Combat Summits were noted. Specifics of the methods of the Summit are presented elsewhere in this supplement.

RESULTS

We formulated research and policy recommendations for urogenital health, nutrition and iron-deficiency anemia, contraception and unintended pregnancy, and traumatic brain injury.

CONCLUSIONS

In order to continue to develop the future health of military women, health care providers, researchers, and policymakers should consider the recommendations made in this supplement as they continue to build on the state of the science and forge the future.

Single and repeated high-level blast, low-level blast, and new-onset self-reported health conditions in the U.S. Millennium Cohort Study: An exploratory investigation

Introduction

Although previous research suggests that overpressure exposure from either high-level blast (HLB) or low-level blast (LLB) are harmful to health, to date no large-scale studies with representative samples of military personnel have utilized prospective designs and self-reported measures to examine the relationships between blast exposure and health conditions. To address these limitations, this analysis of data from the Millennium Cohort Study (MCS), the largest and longest running study of U.S. service members and veterans, examined (1) whether single or repeated HLB exposure is associated with self-reported diagnoses of illness and injury, (2) whether repeated HLB is associated with greater risk than single HLB, (3) potential adverse consequences of LLB exposure using military occupation as a proxy, and (4) the combined effects of single or repeated HLB and LLB exposure.

Method

MCS participants who completed the 2011-2013 survey (N = 138,949) were classified as having been exposed to "no," "single," or "repeated" HLB exposure, and into low or high risk of exposure to LLB based on occupation. Participants self-reported diagnosis of 45 medical conditions; newly reported diagnoses were regressed on single and repeated (vs. no) HLB, occupational risk of LLB, and relevant interactions using logistic regression.

Results

Single and repeated HLB were associated with new onset of 25 and 29 diagnoses, respectively; repeated HLB exposure was associated with greater risk than single HLB exposure for five diagnoses (e.g., PTSD, depression). Occupational risk of LLB was associated with 11 diagnoses (e.g., PTSD, significant hearing loss). Additionally, 14 significant interactions were detected across 11 diagnoses.

Discussion

Findings suggest that overpressure exposure (including single HLB, repeated HLB, and occupational risk of LLB) may increase the risks of self-reporting clinical diagnoses of PTSD, hearing loss, chronic fatigue syndrome, neuropathy-caused reduced sensation in the hands and feet, depression, vision loss, sinusitis, reflux, and anemia. Furthermore, the combination of HLB and LLB exposure may be associated with greater risk of migraines, PTSD, and impaired fecundity. These findings provide further evidence of the potential adverse consequences associated with overpressure exposure and underscore the necessity of public health surveillance initiatives for blast exposure and/or safety recommendations for training and operational environments.

Advocacy for Change: An Osteopathic Review of Traumatic Brain Injury Among Combat Veterans

As a "signature injury" of the Iraq and Afghanistan wars, traumatic brain injury (TBI) remains a major health concern among military service members. Traumatic brain injury is associated with a wide range of symptoms which may be cognitive, emotional, psychological, biochemical, and social in nature. Mild TBI (mTBI) ranks as the most common traumatic brain injury among veterans. Due to the absence of specific symptoms, mTBI diagnosis may be challenging in acute settings. Repetitive traumatic brain injury during combat deployments can lead to devastating chronic neurodegenerative diseases and other major life disruptions. Many cases of TBI remain undetected in veterans and may lead to long-term adverse comorbidities such as post-traumatic stress disorder (PTSD), suicide, alcohol disorders, psychiatric diagnoses, and service-related somatic dysfunctions. Veterans with TBI are almost twice as likely to die from suicide in comparison to veterans without a history of TBI. Veterans diagnosed with TBI experience significant comorbid conditions and thus advocacy for improved care is justified and necessary. Given the complexity and variation in the symptomatology of TBI, a personalized, multimodal approach is warranted in the evaluation and treatment of veterans with TBI and other associated conditions. As such, this review provides a broad overview of treatment options, with an emphasis on advocacy and osteopathic integration in the standard of care for veterans.

Association between perceived distress and salivary cortisol in veterans with mTBI

Mild traumatic brain injury (mTBI) is one of the most common injuries experienced by Veterans and can frequently result in a variety of post-concussive symptoms. Post-concussive headaches (PCH), one of the most common symptoms, can persist for years after the injury occurred. The long-lasting impacts of PCH can be extremely distressing for Veterans, thus necessitating the need to find reliable biomarkers that directly relate to subjective feelings of distress. Yoga-based interventions have been shown to improve both subjective and objective markers of stress. Techniques used in yoga, such as the focus on releasing muscular tension, are also recommended as strategies for treating PCH. Thus, yoga-based interventions provide a unique context for the comparison of subjective and objective measures of distress in Veterans with PCH. In this secondary, exploratory analysis, we examined the relationship between perceived distress and cortisol in sixteen Veterans with mTBI and long-term PCH within the context of a yoga intervention feasibility study. The Visual Analogue Scale (VAS), a validated tool for measuring subjective distress, was administered to participants immediately before and after 75-min yoga classes, which occurred twice weekly over eight weeks. Participants also provided salivary cortisol (pre- and post-yoga) at in-person sessions (eight) to compare to changes in VAS scores. We found that VAS scores were significantly reduced within five of the eight assessed yoga classes, but there were no significant changes in cortisol levels. No significant correlations were found between VAS scores and salivary cortisol levels. When looking at how cortisol levels changed over time (i.e., over the series of eight yoga sessions), there was a significant downward trajectory in post-yoga cortisol, but not after taking pre-class cortisol into account (i.e., within yoga session cortisol change over time). Taken together, we found that subjective distress, but not cortisol was reduced by yoga classes. These data suggest that salivary cortisol did not match changes in perceived distress, thus emphasizing the ongoing challenges of relating subjective and objective measures.

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Perceived distress can negatively impact post-concussive symptoms.

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Efforts are needed to relate objective and subjective measures of distress.

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Subjective distress and salivary cortisol were examined within yoga sessions.

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Subjective distress, but not cortisol was reduced within 5 of 8 yoga classes.

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These data highlight the challenges of relating subjective and objective measures.

fMRI findings in MTBI patients with headaches following rTMS

Mild Traumatic Brain Injury (MTBI) patients with persistent headaches are known to have diminished supraspinal modulatory connectivity from their prefrontal cortices. Repetitive transcranial magnetic stimulation (rTMS) is able to alleviate MTBI-related headache (MTBI-HA). This functional magnetic resonance imaging (fMRI) study assessed supraspinal correlates associated with the headache analgesic effect of rTMS at left prefrontal cortex (LPFC), hypothesizing real rTMS would significantly increase modulatory functions at LPFC in comparison to sham treatment. Subjects with MTBI-HA were randomized to receive either real or sham rTMS treatments and subjected to pre- and post-treatment resting state and evoked heat-pain fMRI as described in a prior study. Real rTMS consisted of 2000 pulses delivered at 10 Hz and 80% of the resting motor threshold at left dorsolateral prefrontal cortex, whereas sham treatment was delivered with same figure-of-eight coil turned 180 degrees. Follow-up fMRI was performed one-week post-treatment. All fMRI data was processed using BrainVoyager QX Software. 14 subjects receiving real and 12 subjects receiving sham treatments completed the study. The REAL group demonstrated significant (P < 0.02) decreases in headache frequency and intensity at one week following treatment. fMRI scans in the REAL group showed increased evoked heat pain activity (P < 0.002) and resting functional connectivity (P < 0.0001) at the LPFC after rTMS. Neither this significant analgesic effect nor these fMRI findings were seen in the sham group. Sham treatment was, however, associated with a decrease in resting state activity at the LPFC (P < 0.0001). This study correlates the demonstrated analgesic effect of rTMS in the treatment of MTBI-HA with enhanced supraspinal functional connectivity in the left prefrontal cortex, which is known to be involved in “top-down” pain inhibition along the descending midbrain-thalamic-cingulate pathway.

Trial Registration: This study was registered on September 24, 2013, on ClinicalTrials.gov with the identifier: NCT01948947. https://clinicaltrials.gov/ct2/show/NCT01948947.

Post-traumatic Headache and Mild Traumatic Brain Injury: Brain Networks and Connectivity

PURPOSE OF REVIEW

Post-traumatic headache (PTH) consequent to mild traumatic brain injury (mTBI) is a complex, multidimensional, chronic neurological disorder. The purpose of this review is to evaluate the current neuroimaging studies on mTBI and PTH with a specific focus on brain networks and connectivity patterns.

RECENT FINDINGS

We present findings on PTH incidence and prevalence, as well as the latest neuroimaging research findings on mTBI and PTH. Additionally, we propose a new strategy in studying PTH following mTBI. The diversity and heterogeneity of pathophysiological mechanisms underlying mild traumatic brain injury pose unique challenges on how we interpret neuroimaging findings in PTH. Evaluating alterations in the intrinsic brain network connectivity patterns using novel imaging and analytical techniques may provide additional insights into PTH disease state and therefore inform effective treatment strategies.

Incidence (2008-2015) of post-traumatic headaches in United States military personnel

Objective: To conduct a descriptive transversal study to evaluate the incidence and demographic characteristics of post-traumatic headache using data from the Defense Medical Epidemiology Database.Methods: A retrospective cohort study was conducted of data from 2008 to 2015 based on the International Classification of Diseases codes for both acute and chronic post-traumatic headache.Results: A total of 17,010 new cases of post-traumatic headaches were diagnosed among active duty military personnel. Reported incidence rates of post-traumatic headaches in the military increased 29-fold over the timeframe analyzed. Males enlisted in the Army were more likely to be diagnosed with post-traumatic headaches than females (O/E = 0.76), other branches, and officers.Conclusion: Findings of this study indicate that there is a significant incidence of post-traumatic headaches in the U.S. military. However, the incidence rates of post-traumatic headaches in the military are much lower than what was expected considering the number of traumatic brain injuries in the United States military reported by the Department of Defense for the same period. Additional research is needed to further evaluate these differences and the impact of PTHs on military personnel.

Provider Training in the Management of Headache Following Concussion Clinical Recommendation: Promoting a Standardized Means for Efficient Patient Recovery and Timely Return to Duty

Background: Headache is a common symptom reported following concussion/mild traumatic brain injury. The Department of Defense's clinical recommendation (CR) describes guidance for primary care providers for the management of post-traumatic headache (PTH) in Service members.

Objective: The objective of this study is to examine the association between training on the CR with provider clinical practice, patient behaviors, and symptom recovery.

Methods: Participants were healthcare providers and two patient groups (one receiving care as usual [CAU] and another receiving care after provider training on PTH CR [CR+]). Providers were interviewed at three time points: (1) prior to CAU enrollment; (2) after CAU enrollment, but prior to training; and (3) after CR+ follow-up. Data from the second and third provider interview were used to evaluate a potential difference between provider practices pre- and post-training (n = 13). Patients were enrolled within 6 months of concussion. Patient outcomes (including neurobehavioral and headache symptoms) were assessed at three time-points: within 72 h (n = 35), at 1-week (n = 34) and at 1-month post-enrollment (n = 27).

Results: Most follow-up care reported by providers were recommended within 72 h of initial visit post-training vs. >1 week pre-training. Additionally, providers reported a greater number of visits based on patient symptoms after training than before. Post-training, most providers reported referring patients to higher level of care “as needed,” if not “very rarely,” compared to 25% reported referrals prior to training. At 1-week post-enrollment the CR+ patient group reported more frequent medical provider visits compared to the CAU group. This trend was reversed at the 1-month follow-up whereby more CAU reported seeing a medical provider compared to CR+. By 1-week post-enrollment, fewer patients in the CR+ group reported being referred to any other providers or specialists compared to the CAU group. No differences in patient outcomes by provider training was found.

Conclusion: The study results demonstrate the feasibility of training on the Management of Headache Following Concussion CR in order to change provider practices by promoting timely care, and promoting patient compliance as shown through improvement in follow-up visits and more monitoring within the primary care clinic.

Characteristics and Impact of U.S. Military Blast-Related Mild Traumatic Brain Injury: A Systematic Review

As a result of armed conflict, head trauma from exposure to blasts is an increasing critical health issue, particularly among military service members. Whilst numerous studies examined the burden of blast-related brain injuries on service members', few systematic reviews have been published. This work provides a comprehensive summary of the evidence on blast-related mild traumatic brain injury (mTBI) burden in active U.S. military service members and inactive Veterans, describing characteristics and outcomes. Records published up to April 2017 were identified through a search of PubMed, Web of Science, Scopus, Ovid MEDLINE, and Cochrane Library. Records-based and original research reporting on U.S. military service members and Veterans with mild blast TBI were included. Data on subject characteristics, exposure, diagnostic criterion, and outcomes were extracted from included studies using a standardized extraction form and were presented narratively. Of the 2,290 references identified by the search, 106 studies with a total of 37,515 participants met inclusion criteria for blast-related mTBI. All but nine studies were based out of military or Veteran medical facilities. Unsurprisingly, men were over-represented (75–100%). The criteria used to define blast-related mTBI were consistent; however, the methodology used to ascertain whether individuals met those criteria for diagnosis were inconsistent. The diagnosis, most prevalent among the Army, heavily relied on self-reported histories. Commonly reported adverse outcomes included hearing disturbances and headaches. The most frequently associated comorbidities were post-traumatic stress disorder, depression, anxiety, sleep disorders, attention disorders, and cognitive disorders. The primary objective of this review was to provide a summary of descriptive data on blast-related mTBI in a U.S. military population. Low standardization of the methods for reaching diagnosis and problems in the study reporting emphasize the importance to collect high-quality data to fill knowledge gaps pertaining to blast-related mTBI.

DNA Methylation Patterns of Chronic Explosive Breaching in U.S. Military Warfighters

Background: Injuries from exposure to explosions rose dramatically during the Iraq and Afghanistan wars, which motivated investigation of blast-related neurotrauma. We have undertaken human studies involving military "breachers" -exposed to controlled, low-level blast during a 3-days explosive breaching course. Methods: We screened epigenetic profiles in peripheral blood samples from 59 subjects (in two separate U.S. Military training sessions) using Infinium MethylationEPIC BeadChips. Participants had varying numbers of exposures to blast over their military careers (empirically defined as high ≥ 40, and conversely, low < 39 breaching exposures). Daily self-reported physiological symptoms were recorded. Tinnitus, memory problems, headaches, and sleep disturbances are most frequently reported. Results: We identified 14 significantly differentially methylated regions (DMRs) within genes associated with cumulative blast exposure in participants with high relative to low cumulative blast exposure. Notably, NTSR1 and SPON1 were significantly differentially methylated in high relative to low blast exposed groups, suggesting that sleep dysregulation may be altered in response to chronic cumulative blast exposure. In comparing lifetime blast exposure at baseline (prior to exposure in current training), and top associated symptoms, we identified significant DMRs associated with tinnitus, sleep difficulties, and headache. Notably, we identified KCNN3, SOD3, MUC4, GALR1, and WDR45B, which are implicated in auditory function, as differentially methylated associated with self-reported tinnitus. These findings suggest neurobiological mechanisms behind auditory injuries in our military warfighters and are particularly relevant given tinnitus is not only a primary disability among veterans, but has also been demonstrated in active duty medical records for populations exposed to blast in training. Additionally, we found that differentially methylated regions associated with the genes CCDC68 and COMT track with sleep difficulties, and those within FMOD and TNXB track with pain and headache. Conclusion: Sleep disturbances, as well as tinnitus and chronic pain, are widely reported in U.S. military service members and veterans. As we have previously demonstrated, DNA methylation encapsulates lifetime exposure to blast. The current data support previous findings and recapitulate transcriptional regulatory alterations in genes involved in sleep, auditory function, and pain. These data uncovered novel epigenetic and transcriptional regulatory mechanism underlying the etiological basis of these symptoms.

Post-traumatic cephalalgia

After traumatic brain injury (TBI), a host of symptoms of varying severity and associated functional impairment may occur. One of the most commonly encountered and challenging to treat are the post-traumatic cephalalgias. Post-traumatic cephalalgia (PTC) or headache is often conceptualized as a single entity as currently classified using the ICHD-3. Yet, the terminology applicable to the major primary, non-traumatic, headache disorders such as migraine, tension headache, and cervicogenic headache are often used to specify the specific type of headache the patients experiences seemingly disparate from the unitary definition of post-traumatic headache adopted by ICHD-3. More complex post-traumatic presentations attributable to brain injury as well as other headache conditions are important to consider as well as other causes such as medication overuse headache and medication induced headache. Treatment of any post-traumatic cephalalgia must be optimized by understanding that there may be more than one headache pain generator, that comorbid traumatic problems may contribute to the pain presentation and that pre-existing conditions could impact both symptom complaint, clinical presentation and recovery. Any treatment for PTC must harmonize with ongoing medical and psychosocial aspects of recovery.

Current patterns of primary care provider practices for the treatment of post-traumatic headache in active duty military settings

Objective

To provide a preliminary assessment of the current clinical practice for the treatment of post-traumatic headache following concussion in military primary health care settings.

Background

Headache is one of the most common symptoms post-concussion; however, little is known of the current clinical practices of primary care providers (on the treatment of post-traumatic headache), particularly in military settings.

Methods

Study participants were primary care providers (n = 65) who treated active duty Service members suffering from post-traumatic headache at two military installations. Qualitative data gathered via semi-structured interviews were used to describe provider practices and experience in treating patients with post-traumatic headache.

Results

Some patterns of care across primary care providers treating post-traumatic headache were consistent with the Department of Defense-recommended clinical recommendation (e.g., recommendation of both pharmacological and non-pharmacological treatment [89.4%]; engaging in follow-up care [100%]). Differences existed in timing of follow-up from initial visit [16.9% reporting within 24 hours; 21.5% reporting within 48–72 hours; and 26.2% reporting more than 1 week], the factors contributing to the type of care given (e.g., symptomatology [33.0%], injury characteristic [24.2%], patient characteristic [13.2%]) and the need for referral to higher level of care (e.g., symptomatology [44.6%], treatment failure [25.0%]). These variations may be indicative of individualized treatment which would be compliant with best clinical practice.

Conclusion

The results of this study demonstrate the current clinical practice in military primary care settings for the treatment of post-traumatic headache which can potentially inform and improve implementation of provider training and education.

Addressing chronic persistent headaches after MTBI as a neuropathic pain state

An increasing number of patients with chronic persistent post-traumatic headache (PPTH) after mild traumatic brain injury (MTBI) are being referred to headache or pain specialists as conventional treatment options for primary headache disorders have not been able to adequately alleviate their debilitating headache symptoms. Evolving clinical and mechanistic evidences support the notation that chronic persistent MTBI related headaches (MTBI-HA) carry the hallmark characteristics of neuropathic pain. Thus, in addition to conventional treatment options applicable to non-traumatic primary headache disorders, other available treatment modalities for neuropathic pain should be considered. In this comprehensive review article, the author reveals the prevalence of MTBI-HA and its clinical manifestation, discusses existing clinical and mechanistic evidence supporting the classification of chronic persistent MTBI-HA as a neuropathic pain state, and explores current available treatment options and future directions of therapeutic research related to MTBI-HA.

Transcranial Magnetic Stimulation for Pain, Headache, and Comorbid Depression: INS-NANS Expert Consensus Panel Review and Recommendation

BACKGROUND

While transcranial magnetic stimulation (TMS) has been studied for the treatment of psychiatric disorders, emerging evidence supports its use for pain and headache by stimulating either motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC). However, its clinical implementation is hindered due to a lack of consensus in the quality of clinical evidence and treatment recommendation/guideline(s). Thus, working collaboratively, this multinational multidisciplinary expert panel aims to: 1) assess and rate the existing outcome evidence of TMS in various pain/headache conditions; 2) provide TMS treatment recommendation/guidelines for the evaluated conditions and comorbid depression; and 3) assess the cost-effectiveness and technical issues relevant to the long-term clinical implementation of TMS for pain and headache.

METHODS

Seven task groups were formed under the guidance of a 5-member steering committee with four task groups assessing the utilization of TMS in the treatment of Neuropathic Pain (NP), Acute Pain, Primary Headache Disorders, and Posttraumatic Brain Injury related Headaches (PTBI-HA), and remaining three assessing the treatment for both pain and comorbid depression, and the cost-effectiveness and technological issues relevant to the treatment.

RESULTS

The panel rated the overall level of evidence and recommendability for clinical implementation of TMS as: 1) high and extremely/strongly for both NP and PTBI-HA respectively; 2) moderate for postoperative pain and migraine prevention, and recommendable for migraine prevention. While the use of TMS for treating both pain and depression in one setting is clinically and financially sound, more studies are required to fully assess the long-term benefit of the treatment for the two highly comorbid conditions, especially with neuronavigation.

CONCLUSIONS

After extensive literature review, the panel provided recommendations and treatment guidelines for TMS in managing neuropathic pain and headaches. In addition, the panel also recommended more outcome and cost-effectiveness studies to assess the feasibility of the long-term clinical implementation of the treatment.

Chronic pain after blast-induced traumatic brain injury in awake rats

Explosive blast-induced traumatic brain injury (blast-TBI) in military personnel is a leading cause of injury and persistent neurological abnormalities, including chronic pain. We previously demonstrated that chronic pain after spinal cord injury results from central sensitization in the posterior thalamus (PO). The presence of persistent headaches and back pain in veterans with blast-TBI suggests a similar involvement of thalamic sensitization. Here, we tested the hypothesis that pain after blast-TBI is associated with abnormal increases in activity of neurons in PO thalamus. We developed a novel model with two unique features: (1) blast-TBI was performed in awake, un-anesthetized rats, to simulate the human experience and to eliminate confounds of anesthesia and surgery inherent in other models; (2) only the cranium, rather than the entire body, was exposed to a collimated blast wave, with the blast wave striking the posterior cranium in the region of the occipital crest and foramen magnum. Three weeks after blast-TBI, rats developed persistent, ongoing spontaneous pain. Contrary to our hypothesis, we found no significant differences in the activity of PO neurons, or of neurons in the spinal trigeminal nucleus. There were also no significant changes in gliosis in either of these structures. This novel model will allow future studies on the pathophysiology of chronic pain after blast-TBI.

Relationships and Evidence-Based Theoretical Perspectives on Persisting Symptoms and Functional Impairment Among Mild Traumatic Brain Injury and Behavioral Health Conditions

The purpose of this study is to characterize and describe the relationships between symptoms and functional impairment following mild traumatic brain injury (mTBI) and behavioral health conditions (BHCs) in order to inform evidence-based theories on why symptoms and functional impairments persist in some individuals but not others. This is a retrospective, multi-site, cross-sectional study utilizing data collected from a total of 289 Operation Iraqi Freedom/Operation Enduring Freedom Veterans who were classified into diagnostic groups using the symptom attribution and classification algorithm and the VA clinical reminder and comprehensive traumatic brain injury evaluation. The Neurobehavioral Symptom Inventory was used to assess mTBI symptom number and severity. The World Health Organization Disability Assessment Schedule 2.0 was used to assess functional impairment. Symptom profiles differed between diagnostic groups irrespective of symptom attribution method used. Veterans with both mTBI and BHCs and those with BHCs alone had consistently greater number of symptoms and more severe symptoms relative to no symptom and symptoms resolved groups. Symptom number and severity were significantly associated with functional impairment. Both symptom number and functional impairment were significantly associated with the number of mTBI exposures. Together, these results informed evidence-based theories on understanding why symptoms and functional impairment persist among some OEF/OIF Veterans.

Management of Chronic Migraine and Occipital Neuralgia in Post 9/11 Combat Veterans

Introduction

The rate of chronic migraine (CM) has been shown to be 20% or greater in the post 9/11 combat veteran population with a history of traumatic brain injury, while the rate is much lower at 3–5% in the general population. Studies have shown that medications such as oral topiramate or intramuscular injections of onabotulinum toxin A (Botox) have been used for CM prevention, and occipital blocks have been shown to be helpful in treating occipital neuralgia and short-term relief of CM. However, there are no known studies that have specifically evaluated the use of Botox and occipital blocks for reducing headache frequency in the US veteran population. The purpose of this study was to evaluate the effectiveness of using occipital blocks and Botox as dual therapy for reducing headache frequency in post 9/11 combat veterans with CM, occipital neuralgia, and a history of TBI or neck trauma.

Materials and Methods

Following Institutional Review Board approval, a retrospective chart review was completed on post 9/11 combat veterans treated in a headache clinic located at the Central Texas Veteran Health Care System. The electronic medical record was used to retrieve the charts of post 9/11 combat veterans who (1) had a confirmed deployment-related history of TBI or neck trauma; (2) were diagnosed with CM and occipital neuralgia; and (3) were treated in the headache clinic between January 1, 2014 and December 31, 2015 with the administration of occipital blocks and Botox within the first six months. Of 282 charts that were reviewed, a total of 30 (N = 30) veterans fit the criteria. The mean number of self-reported headache days per month (28 days) for the month prior to starting treatment was compared to the number of headache days per month (28 days) 6 months after initiation of therapy.

Results

Results revealed that the mean number of headache days in the month prior to treatment was 24.1 (22.0, 25.7). The mean number of headache days in the month post-treatment (6 months after the initiation of dual therapy with occipital blocks and Botox) was 12.9 (9.7, 16.4). The mean difference in the number of headache days from pre- to post-treatment (pre-treatment minus post-treatment) was 11.2 (8.2, 14.2).

Conclusion

This study evaluated the effectiveness of using occipital blocks and Botox as dual therapy for reducing headache frequency for post 9/11 combat veterans with CM, occipital neuralgia, and a history of TBI or neck trauma. Results revealed a statistically significant reduction in the number of headache days per month after the dual therapy. There were multiple limitations to the study to include a small sample size, lack of a control group, self-reported headaches for only 1 month pre-and post-treatment, and no control for other interventions or events which may have influenced the outcome. There is a strong need for randomized, double blinded, placebo- controlled studies involving dual therapy in this population. This study, though small, may be helpful in stimulating additional studies and treatments in this veteran population.

Prevalence of comorbid chronic pain and mental health conditions in Canadian Armed Forces active personnel: analysis of a cross-sectional survey

BACKGROUND

Chronic pain conditions and mental disorders have high prevalence rates in military populations. However, few investigations have examined the comorbidity between chronic pain conditions and specific mental disorders among Canadian active military personnel.

METHODS

We conducted a secondary analysis of data from the 2013 Canadian Forces Mental Health Survey (CFMHS) concerning the population of regular members. Diagnostic interviews assessed the presence of mental disorders, and participants self-reported chronic pain conditions (i.e., arthritis, back problems, musculoskeletal conditions, migraines) and indicators of pain severity. We used multiple logistic regressions to assess associations between chronic pain conditions and mental disorders. We used cross-tabulations to assess the prevalence of pain severity indicators in comorbid relationships compared with the chronic pain condition alone. We used moderation analyses to examine the interactions between pain condition by pain severity, and pain condition by activity limitation, respectively, on mental disorders.

RESULTS

The CFMHS included data from 6696 regular members and had a response rate of 79.8%. About one-quarter (n = 1761) of military personnel reported having chronic pain. In the fully adjusted model, all assessed pain conditions were significantly associated with posttraumatic stress disorder (PTSD) (odds ratio [OR] range 1.86-2.55), and several pain conditions were associated with major depressive episode, generalized anxiety disorder and panic disorder. Back problems were significantly associated with all mental disorders apart from alcohol use disorders (OR range 1.40-2.17). Cross-tabulations showed higher prevalence estimates of endorsement for pain severity indicators among pain conditions and comorbid mental disorders, compared with pain conditions alone. Formal moderation analyses showed a significant relationship between migraine and activity limitation on PTSD.

INTERPRETATION

Chronic pain conditions are prevalent and co-occur with mental disorders among Canadian regular force members. Greater understanding of these chronic pain conditions and mental disorders and their impact on people's abilities to adapt to both military and civilian life is needed.

Posttraumatic Headache: Classification by Symptom-Based Clinical Profiles

There are currently no accepted therapies for posttraumatic headache (PTH). In order to meet the urgent need for effective therapies for PTH, we must continue to address fundamental gaps in our understanding of the clinical course and impact of PTH. Here we examine the existing schema used to characterize the clinical characteristics of PTH, including the International Classification of Headache Disorders (ICHD). There remain unresolved questions about whether to classify patients based on the extent of brain injury or on clinical symptom profiles. There also remain problematic issues of definition such as continuous headache, and chronic daily headache with features of "embedded" migraine-type within these headaches, which will need to be studied further. We make the case that a symptom-based classification is needed to begin an examination of these unresolved questions, and to establish clinically relevant endpoints for research and clinical trials for effective therapies.

Repeat low-level blast exposure increases transient receptor potential vanilloid 1 (TRPV1) and endothelin-1 (ET-1) expression in the trigeminal ganglion

Blast-associated sensory and cognitive trauma sustained by military service members is an area of extensively studied research. Recent studies in our laboratory have revealed that low-level blast exposure increased expression of transient receptor potential vanilloid 1 (TRPV1) and endothelin-1 (ET-1), proteins well characterized for their role in mediating pain transmission, in the cornea. Determining the functional consequences of these alterations in protein expression is critical to understanding blast-related sensory trauma. Thus, the purpose of this study was to examine TRPV1 and ET-1 expression in ocular associated sensory tissues following primary and tertiary blast. A rodent model of blast injury was used in which anesthetized animals, unrestrained or restrained, received a single or repeat blast (73.8 ± 5.5 kPa) from a compressed air shock tube once or daily for five consecutive days, respectively. Behavioral and functional analyses were conducted to assess blast effects on nocifensive behavior and TRPV1 activity. Immunohistochemistry and Western Blot were also performed with trigeminal ganglia (TG) to determine TRPV1, ET-1 and glial fibrillary associated protein (GFAP) expression following blast. Increased TRPV1, ET-1 and GFAP were detected in the TG of animals exposed to repeat blast. Increased nocifensive responses were also observed in animals exposed to repeat, tertiary blast as compared to single blast and control. Moreover, decreased TRPV1 desensitization was observed in TG neurons exposed to repeat blast. Repeat, tertiary blast resulted in increased TRPV1, ET-1 and GFAP expression in the TG, enhanced nociception and decreased TRPV1 desensitization.

Pathophysiological links between traumatic brain injury and post-traumatic headaches

This article reviews possible ways that traumatic brain injury (TBI) can induce migraine-type post-traumatic headaches (PTHs) in children, adults, civilians, and military personnel. Several cerebral alterations resulting from TBI can foster the development of PTH, including neuroinflammation that can activate neural systems associated with migraine. TBI can also compromise the intrinsic pain modulation system and this would increase the level of perceived pain associated with PTH. Depression and anxiety disorders, especially post-traumatic stress disorder (PTSD), are associated with TBI and these psychological conditions can directly intensify PTH. Additionally, depression and PTSD alter sleep and this will increase headache severity and foster the genesis of PTH. This article also reviews the anatomic loci of injury associated with TBI and notes the overlap between areas of injury associated with TBI and PTSD.

Headache in military service members with a history of mild traumatic brain injury: A cohort study of diagnosis and classification

Introduction

Headaches after concussion are highly prevalent, relatively persistent and are being treated like primary headaches, especially migraine.

Methods

We studied all new patients seen between August 2008 and December 2009 assessed by a civilian headache specialist at the TBI Center at Womack Army Medical Center, Fort Bragg, NC. We report sample demographics, injuries and headache characteristics, including time from injury to headache onset, detailed descriptions and International Classification of Headache Disorders second edition primary headache diagnosis type.

Results

A total of 95 soldiers reported 166 headaches. The most common injury cited was a blast (53.7%). Most subjects (76.8%) recalled the onset of any headache within 7 days of injury. The most commonly diagnosed headache was a continuous type with migraine features ( n = 31 (18.7%)), followed by chronic migraine (type 1.5.1, n = 14 (8.4%)), migraine with aura (type 1.2.1, n = 10 (6.0%)), hemicrania continua (type 4.7, n = 12 (7.2%)), chronic cluster (type 3.1.2, n = 6 (3.6%)) and headaches not otherwise classifiable (type 14.1, n = 5 (3.0%)) also present. The most clinically important was a continuous headache with migraine features.

Conclusion

We present a series of patients seen in a military treatment facility for headache diagnosis after concussion in whom we found migraine, as well as uncommon primary headache types, at frequencies that were much higher than expected.

Low-Level Blast Exposure Increases Transient Receptor Potential Vanilloid 1 (TRPV1) Expression in the Rat Cornea

Background: Blast-related ocular injuries sustained by military personnel have led to rigorous efforts to elucidate the effects of blast exposure on neurosensory function. Recent studies have provided some insight into cognitive and visual deficits sustained following blast exposure; however, limited data are available on the effects of blast on pain and inflammatory processes. Investigation of these secondary effects of blast exposure is necessary to fully comprehend the complex pathophysiology of blast-related injuries. The overall purpose of this study is to determine the effects of single and repeated blast exposure on pain and inflammatory mediators in ocular tissues.

Methods: A compressed air shock tube was used to deliver a single or repeated blast (68.0 ± 2.7 kPa) to anesthetized rats daily for 5 days. Immunohistochemistry was performed on ocular tissues to determine the expression of the transient receptor potential vanilloid 1 (TRPV1) channel, calcitonin gene-related peptide (CGRP), substance P (SP), and endothelin-1 (ET-1) following single and repeated blast exposure. Neutrophil infiltration and myeloperoxidase (MPO) expression were also assessed in blast tissues via immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) analysis, respectively.

Results: TRPV1 expression was increased in rat corneas exposed to both single and repeated blast. Increased secretion of CGRP, SP, and ET-1 was also detected in rat corneas as compared to control. Moreover, repeated blast exposure resulted in neutrophil infiltration in the cornea and stromal layer as compared to control animals.

Conclusion: Single and repeated blast exposure resulted in increased expression of TRPV1, CGRP, SP, and ET-1 as well as neutrophil infiltration. Collectively, these findings provide novel insight into the activation of pain and inflammation signaling mediators following blast exposure.

Traumatic Brain Injury in United States Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Hispanic Veterans-A Review Using the PRISMA Method

Traumatic brain injury (TBI) is commonly defined by Menon et al. as an "alteration of the brain function, or other evidence of brain pathology, caused by an external force." TBI can be caused by penetrating trauma to the head in which the magnitude of the injury is dependent on the magnitude of the forces that are applied to the head. The consequences of TBI can range from minimal to severe disability and even death. The major objectives of this systematic review are to survey the current literature on Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Hispanic veterans with TBI. To complete this analysis, the Preferred Reporting Items for Systematic Reviews and MetaAnalysis (PRISMA) identified 875 articles in common and retrieved a total of 34 articles that met the inclusion criteria, consisted of OEF/OIF Hispanic veterans, reported quantitative data, and were conducted with adult U.S. veterans living in the United States. Since TBI diagnosis was unclear in most articles, only five articles that used the VATBIST instrument were analyzed. The results suggested that there is a lack of research on OEF/OIF Hispanic veterans and Hispanic subgroups. Future studies need to be conducted to consider minority groups while analyzing data involving TBI.

A cohort study examining headaches among veterans of Iraq and Afghanistan wars: Associations with traumatic brain injury, PTSD, and depression

OBJECTIVES

To describe the prevalence and persistence of headache and associated conditions in an inception cohort of U.S. veterans of Iraq and Afghanistan wars.

BACKGROUND

Iraq and Afghanistan war veterans (IAV) suffer from persistent and difficult-to-treat headaches that have been found to co-occur with traumatic brain injury (TBI) and other deployment related comorbidities.

METHODS

This longitudinal retrospective cohort study used data from the national Veterans Health Administration (VA) data repository for IAV who first received VA care in 2008 (baseline) and also received care each year in 2009, 2010, and 2011. We used ICD-9-CM codes, to identify those treated for headache each year (2008-2011). Individuals with headache diagnosed each year were classified as having persistent headache. We also identified comorbidities that may be associated with baseline headache using algorithms validated for use with ICD-9-CM codes. Comorbidities included TBI, posttraumatic stress disorder (PTSD), depression, and conditions associated with these diagnoses (anxiety, memory/attention/cognition, neck pain, tinnitus/hyperacusis, photosensitivity/photo blurring, insomnia, malaise/fatigue, and vertigo/dizziness). Multivariable logistic regression analysis was used to determine characteristics associated with baseline headache as well as those associated with persistent headache.

RESULTS

Among all IAV, 38,426 received their first year of VA care in 2008 and had care each year 2009-2011: 13.7% of these were diagnosed with headache in 2008. Veterans diagnosed with headache in 2008 were more likely than those without a headache diagnosis to also have a diagnosis of TBI alone (adjusted odds ratios [AOR] 6.75; 95% CI 5.79-7.86), TBI + depression (AOR 7.09; 95% CI 5.23-9.66), TBI + PTSD (AOR 10.16; 95% CI 8.96-11.53), TBI + PTSD + depression (AOR 9.40; 95% CI 8.12-10.09), and neck pain (AOR 2.44; 95% CI 2.14-2.77). Among those with headache diagnosis in 2008, 24.3% had a headache diagnosis each of the subsequent years of care (persistent headache). While diagnoses of TBI, PTSD, and/or depression at baseline were not associated with headache persistence, persistence was more likely for individuals with baseline tinnitus/hyperacusis (AOR 1.21; 95% CI 1.02-1.45), insomnia (AOR 1.19; 95% CI 1.02-1.39), and vertigo/dizziness (AOR 1.83; 95% CI 1.30-2.57).

CONCLUSIONS

Our results indicate that TBI alone is a strong predictor of headache in the first year of VA care among IAV and that comorbid psychiatric comorbidities increase the likelihood of headache among individuals with TBI. However, among those with baseline headache, only tinnitus, insomnia, and vertigo were baseline clinical predictors of headache persistence. These results suggest that attention to other symptoms and conditions early in the diagnosis and treatment of headaches may be important for understanding prognosis. These comorbidities offer potential targets for intervention strategies that may help address postdeployment headaches.

Post-traumatic headaches in civilians and military personnel: a comparative, clinical review

Post-traumatic headache (PTH) is the most frequent symptom after traumatic brain injury (TBI). We review the epidemiology and characterization of PTH in military and civilian settings. PTH appears to be more likely to develop following mild TBI (concussion) compared with moderate or severe TBI. PTH often clinically resembles primary headache disorders, usually migraine. For migraine-like PTH, individuals who had the most severe headache pain had the highest headache frequencies. Based on studies to date in both civilian and military settings, we recommend changes to the current definition of PTH. Anxiety disorders such as post-traumatic stress disorder (PTSD) are frequently associated with TBI, especially in military populations and in combat settings. PTSD can complicate treatment of PTH as a comorbid condition of post-concussion syndrome. PTH should not be treated as an isolated condition. Comorbid conditions such as PTSD and sleep disturbances also need to be treated. Double-blind placebo-controlled trials in PTH population are necessary to see whether similar phenotypes in the primary headache disorders and PTH will respond similarly to treatment. Until blinded treatment trials are completed, we suggest that, when possible, PTH be treated as one would treat the primary headache disorder(s) that the PTH most closely resembles.

Effect of lacosamide on structural damage and functional recovery after traumatic brain injury in rats

In a subgroup of patients, traumatic brain injury (TBI) results in the occurrence of acute epileptic seizures or even status epilepticus, which are treated with antiepileptic drugs (AEDs). Recent experimental data, however, suggest that administration of AEDs at the early post-injury phase can compromise the recovery process. The present study was designed to assess the profile of a novel anticonvulsant, lacosamide (Vimpat) on post-TBI structural, motor and cognitive outcomes. Moderate TBI was induced by lateral fluid-percussion injury in adult rats. Treatment with 0.9% saline or lacosamide (30 mg/kg, i.p.) was started at 30 min post-injury and continued at 8h intervals for 3d (total daily dose 90 mg/kg/d). Rats were randomly assigned to 4 treatment groups: sham-operated controls treated with vehicle (Sham-Veh) or lacosamide (Sham-LCM) and injured animals treated with vehicle (TBI-Veh) or lacosamide (TBI-LCM). As functional outcomes we tested motor recovery with composite neuroscore and beam-walking at 2, 7, and 15 d post-injury. Cognitive recovery was tested with the Morris water-maze at 12-14 d post-TBI. To assess the structural outcome, animals underwent magnetic resonance imaging (MRI) at 2 d post-TBI. At 16d post-TBI, rats were perfused for histology to analyze cortical and hippocampal neurodegeneration and axonal damage. Our data show that at 2 d post-TBI, both the TBI-Veh and TBI-LCM groups were equally impaired in neuroscore. Thereafter, motor recovery occurred similarly during the first week. At 2 wk post-TBI, recovery of the TBI-LCM group lagged behind that in the TBI-VEH group (p<0.05). Performance in beam-walking did not differ between the TBI-Veh and TBI-LCM groups. Both TBI groups were similarly impaired in the Morris water-maze at 2 wk post-TBI. MRI and histology did not reveal any differences in the cortical or hippocampal damage between the TBI-Veh and TBI-LCM groups. Taken together, acute treatment with LCM had no protective effects on post-TBI structural or functional impairment. Composite neuroscore in the TBI-LCM group lagged behind that in the TBI-Veh group at 15 d post-injury, but no compromise was found in other indices of post-TBI recovery in the LCM treated animals.

Factors Associated with Mild Traumatic Brain Injury in Veterans and Military Personnel: A Systematic Review

A history of mild traumatic brain injury (mTBI) is common among military members who served in Operations Enduring Freedom, Iraqi Freedom, and New Dawn (OEF/OIF/OND). We completed a systematic review to describe the cognitive, mental health, physical health, functional, social, and cost consequences of mTBI in Veteran and military personnel. Of 2668 reviewed abstracts, the 31 included studies provided very low strength evidence for the questions of interest. Cognitive, physical, and mental health symptoms were commonly reported by Veterans/military members with a history of mTBI. On average, these symptoms were not significantly more common in those with a history of mTBI than in those without, although a lack of significant mean differences does not preclude the possibility that some individuals could experience substantial effects related to mTBI history. Evidence of potential risk or protective factors moderating mTBI outcomes was unclear. Although the overall strength of evidence is very low due to methodological limitations of included studies, our findings are consistent with civilian studies. Appropriate re-integration services are needed to address common comorbid conditions, such as treatment for post-traumatic stress disorder, substance use disorders, headaches, and other difficulties that Veterans and members of the military may experience after deployment regardless of mTBI history. (JINS, 2014, 20, 1-13).

Prescription headache medication in OEF/OIF veterans: results from the Women Veterans Cohort Study

OBJECTIVE

To examine differences in male and female veterans of Operations Enduring Freedom/Iraqi Freedom (OEF/OIF) period of service in taking prescription headache medication, and associations between taking prescription headache medication and mental health status, psychiatric symptoms, and rates of traumatic events.

BACKGROUND

Headaches are common among active service members and are associated with impairment in quality of life. Little is known about headaches in OEF/OIF veterans.

METHODS

Veterans participating in the Women Veterans Cohort Study responded to a cross-sectional survey to assess taking prescription headache medication, mental health status (Post Deployment Health Assessment), psychiatric symptoms (portions of the Brief Patient Health Questionnaire and the Posttraumatic Stress Disorder Checklist), and traumatic events (the Traumatic Life Events Questionnaire and queries regarding military trauma). Gender differences among taking prescription headache medication, health status, psychiatric symptoms, and traumatic events were examined. Regression analyses were used to examine the influence of gender on the associations between taking prescription headache medication and health status, psychiatric symptoms, and traumatic events.

RESULTS

139/551 (25.2%) participants reported taking prescription headache medication in the past year. A higher proportion of women veterans (29.1%) reported taking prescription medication for headache in the last year compared with men (19.7%). Taking prescription headache medication was associated with poorer perceived mental health status, higher anxiety and posttraumatic stress disorder symptoms, and higher rates of traumatic events. The association between prescription headache medication use and perceived mental health status, and with the association between prescription headache medication use and posttraumatic stress disorder symptoms, was stronger for men than for women.

CONCLUSIONS

Among OEF/OIF veterans, the prevalence of clinically relevant headache is high, particularly among women veterans. Taking prescription headache medication is associated with poor mental health status, higher rates of psychiatric symptoms, and higher rates of traumatic events; however, these variables did not appear to meaningfully account for gender differences in prevalence of taking prescription headache medication. Future research should endeavor to identify factors that might account for the observed differences.