Associations among pain, PTSD, mTBI, and heart rate variability in veterans of Operation Enduring and Iraqi Freedom: a pilot study

Neuromodulation Applied to Diseases: The Case of HRV Biofeedback

The vagus or “wandering” nerve is the main branch of the parasympathetic nervous system (PNS), innervating most internal organs crucial for health. Activity of the vagus nerve can be non-invasively indexed by heart-rate variability parameters (HRV). Specific HRV parameters predict less all-cause mortality, lower risk of and better prognosis after myocardial infarctions, and better survival in cancer. A non-invasive manner for self-activating the vagus is achieved by performing a slow-paced breathing technique while receiving visual feedback of one’s HRV, called HRV-biofeedback (HRV-B). This article narratively reviews the biological mechanisms underlying the role of vagal activity and vagally mediated HRV in hypertension, diabetes, coronary heart disease (CHD), cancer, pain, and dementia. After searching the literature for HRV-B intervention studies in each condition, we report the effects of HRV-B on clinical outcomes in these health conditions, while evaluating the methodological quality of these studies. Generally, the levels of evidence for the benefits of HRV-B is high in CHD, pain, and hypertension, moderate in cancer, and poor in diabetes and dementia. Limitations and future research directions are discussed.

Initial exploration of the discriminatory ability of the PetPace collar to detect differences in activity and physiological variables between healthy and osteoarthritic dogs

Background

Accelerometry has been used to evaluate activity in dogs with osteoarthritis (OA) pain, especially in relation to effect of treatment; however no studies have compared accelerometry-measured activity in dogs with OA-pain and healthy dogs. The aims of this study were to (1) compare activity output from the PetPace collar with the validated Actical monitor and (2) determine if PetPace collar outputs (overall activity, activity levels, body position, and vital signs) differed between healthy dogs and dogs with OA-pain.

Methods

This was an observational, non-interventional study in healthy dogs and dogs with OA-pain. All dogs were outfitted with the PetPace collar and the Actical monitor simultaneously for 14 days. Output from these devices was compared (correlations), and output from the PetPace device was used to explore differences between groups across the activity and vital sign outputs (including calculated heart rate variability indices).

Results

There was moderate correlation between the PetPace collar and Actical monitor output (R² = 0.56, p < 0.001). Using data generated by the PetPace collar, OA-pain dogs had lower overall activity counts and spent less time standing than healthy dogs. Healthy dogs spent more time at higher activity levels than OA-pain dogs. Certain heart rate variability indices in OA-pain dogs were lower than in healthy dogs.

Conclusions and clinical relevance

The results of this study suggest that the PetPace collar can detect differences between healthy dogs and those with OA-pain, and that OA-pain negatively impacts overall activity levels in dogs, and especially higher intensity activity.

Assessing the Clinical Utility of a Wearable Device for Physiological Monitoring of Heart Rate Variability in Military Service Members with Traumatic Brain Injury

Introduction: Autonomic dysfunction has been implicated as a consequence of traumatic brain injury (TBI). Heart rate variability (HRV) may be a viable measure of autonomic dysfunction that could enhance rehabilitative interventions for individuals with TBI. This pilot study sought to assess the feasibility and validity of using the Zeriscope™ platform system in a real-world clinical setting to measure HRV in active-duty service members with TBI who were participating in an intensive outpatient program. Methods: Twenty-five service members with a history of mild, moderate, or severe TBI were recruited from a military treatment facility. A baseline assessment was conducted in the cardiology clinic where point validity data were obtained by comparing a 5-min recording of a standard 12-lead electrocardiogram (ECG) output against the Zeriscope platform data. Results: Compared with the ECG device, the Zeriscope device had a concordance coefficient (rc) of 0.16, falling below the standard deemed to represent acceptable accuracy in HR measurement (i.e., 0.80). Follow-up analyses excluding outliers did not significantly improve the concordance coefficient to an acceptable standard for the total participant sample. System Usability Survey responses showed that participants rated the Zeriscope system as easy to use and something that most people would learn to use quickly. Conclusions: This study demonstrated promise in ambulatory HRV measurement in a representative military TBI sample. Future research should include further refinement of such ambulatory devices to meet the specifications required for use in a military active-duty TBI population.

Autonomic dysfunction in adults following mild traumatic brain injury: A systematic review

BACKGROUND

Increasing evidence suggests autonomic nervous system (ANS) dysfunction may occur following mild traumatic brain injury (mTBI). Measures of heart rate, heart rate variability, blood pressure and baroreceptor sensitivity can be used to evaluate ANS dysfunction following mTBI.

OBJECTIVE

Summarize the evidence for ANS dysfunction in adults following mTBI.

METHODS

A search of Embase, MEDLINE, Cochrane Central Register, PsycINFO, CINAHL and SPORTDiscus databases was conducted. Search topics included: mTBI and ANS. Identified abstracts were independently reviewed by 2 reviewers followed by full text screening. Risk of bias was assessed using a modified SIGN checklist. A structured synthesis was performed.

RESULTS

Thirty-nine studies (combined 1,467 participants diagnosed with mTBI) evaluating ANS function were included. ANS function was evaluated under various conditions including: rest, during exertion, cold pressor test, Valsalva maneuver, using face cooling and eyeball pressure paradigms. Short-term or ultra-short-term recordings were most common. The majority of studies (28/39) were rated as "unacceptable" for quality of evidence.

CONCLUSIONS

Altered parameters of ANS function have been reported in multiple conditions following mTBI, both acutely and in the post-acute/chronic stages of recovery. However, due to methodological limitations, conclusions regarding the severity and timing of ANS dysfunction following mTBI cannot be drawn.

Veterans' Insights on Heart Rate Variability Biofeedback to Treat Fibromyalgia-Related Pain

BACKGROUND

Heart rate variability biofeedback (HRVB) is a self-management strategy that guides individuals to breathe at a designated resonance frequency of the cardiovascular system. Resonant breathing may reduce FM-related symptoms as well as improve physical functioning and quality of life. Although prior research recommends HRVB for chronic pain, we found no studies testing the feasibility for individuals with FM regarding protocol adherence or acceptability of the treatment.

AIMS

To determine the feasibility and acceptability of a heart rate variability biofeedback (HRVB) protocol in a group of Veterans with fibromyalgia (FM).

DESIGN

A multi-method feasibility and acceptability study.

SETTINGS

A Veterans Health outpatient pain medicine clinic.

PARTICIPANTS/SUBJECTS

We enrolled 7 women and 3 men between the ages of 33 and 68 years with a diagnosis of FM.

METHODS

We enrolled 10 veterans in a HRVB study using a recommended protocol to treat FM. Veterans were given a HRVB device, emWave2, and instructed to practice at home twice daily for 20 minutes per session. Following a 7-week intervention period, we conducted an end of study focus group. We used content analysis to develop themes to determine the feasibility of engaging in HRVB and adhering to the intervention protocol, as well as insights of veterans about the intervention.

RESULTS

Three common themes emerged: intervention implementation, protocol adherence, and self-awareness.

CONCLUSIONS

Results of this study suggest difficulties operating the emWave2 and scheduling challenges interfered with HRVB implementation. However, veterans reported self-awareness of the benefits of HRVB, positive physiological effects, and improved psychological effects. Future studies require a larger sample size to provide a deeper insight.

Unclear outcomes of heart rate variability following a concussion: a systematic review

PURPOSE

: To systematically regroup articles that were published since the latest systematic search, but with specific inclusion criteria to help comparison that will offer a focused presentation of methods and results. This will offer a full overview of HRV's behavior at rest and during exercise in adults post-concussion.

METHODS

: The systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method. A computer-based systematic search was conducted in December 2019 through the Pubmed, Scopus and SPORTDiscus databases. A manual search was performed through the reference list of all articles retained. The reliability of the systematic search was assured by having the article selection process entirely repeated by a second author.

RESULTS

: The systematic search yielded a total of 15 articles to be further analyzed. Results show impairment of HRV during exercise for individuals with concussion, heterogenous studies with lack of control over confounding factors and only less than half of the results showing a significant difference between individuals with concussion and controls.

CONCLUSION

: Further research should try standardizing HRV measurement protocols that control confounding factors to allow easier comparison between studies and allows the possibility for an eventual meta-analysis.

Moral Injury in Veterans: Application of the Roy Adaptation Model to Improve Coping

The objective of this article is to provide validation, application, and understanding of the concept of moral injury and build provider awareness to reduce veteran self-harm. Two focus groups were conducted: one to identify characteristics of moral injury and the other to refine the concepts and generate clinical approaches that address maladaptive coping strategies. The focus group sessions verified moral injury's existence, and focus group consensus centered on loss of role identity and shattering of the veteran's core integrity. The veteran's inability to self-reflect is identified as a significant contributor to the maladaptive thought process, creating internal triggers based on violations of deeply held beliefs. A Supplemental Digital Content video abstract is available at http://links.lww.com/ANS/A33.

Use of Mobile Technology Paired with Heart Rate Monitor to Remotely Quantify Behavioral Health Markers among Military Reservists and First Responders

INTRODUCTION

Heart rate variability (HRV) is a biological marker that reflects an individual's autonomic nervous system regulation. Psychological resilience is an individual's ability to recover from an adverse event and return to physiological homeostasis and mental well-being, indicated by higher resting HRV. The Biofeedback Assisted Resilience Training (BART) study evaluates a resilience-building intervention, with or without HRV biofeedback. This article evaluates the feasibility of remote psychophysiological research by validating the HRV data collected.

MATERIALS AND METHODS

The BART platform consists of a mobile health application (BART app) paired to a wearable heart rate monitor. The BART app is installed on the participant's personal phone/tablet to track and collect self-report psychological and physiological data. The platform collects raw heart rate data and processes HRV to server as online biofeedback. The raw data is processed offline to derive HRV for statistical analysis. The following HRV parameters are validated: inter-beat interval, respiratory sinus arrhythmia, low-frequency HRV, biofeedback HRV, and heart period. Bland-Altman and scatter plots are used to compare and contrast online and offline HRV measures. Repeated-measures ANOVA are used to compared means across tasks during the stress (rest, stress, and recovery) and training (rest and paced breathing) sessions in order to validate autonomic nervous system changes to physiological challenges.

RESULTS

The analyses included 245 participants. Bland-Altman plots showed excellent agreement and minimal bias between online and offline unedited inter-beat interval data during the stress session. RMANOVA during the training session indicated a significant strong effect on biofeedback HRV, F(11,390) = 967.96, P < .01. During the stress session, RMANOVA showed significant strong effect on respiratory sinus arrhythmia and low-frequency HRV, and a significant but weak effect on heart period.

CONCLUSIONS

The BART digital health platform supports remote behavioral and physiological data collection, intervention delivery, and online HRV biofeedback.

Trauma-Related Sleep Problems and Associated Health Outcomes in Police Officers: A Path Analysis

Police officers are frequently exposed to two different types of potentially traumatic events: one dealing with physical threats to self and the other involving the witnessing of harm to others. These different types of traumatic experiences are thought to produce various posttraumatic reactions. Furthermore, sleep problems are also reported as a hallmark of posttraumatic stress disorder. There is evidence, however, that sleep problems may mediate the relationship between posttraumatic stress disorder symptoms and health outcomes, especially physical health and depression. Previous research has shown this to be the case among officers from large urban agencies. The purpose of the present study was to test a model involving a pathway from trauma type and posttraumatic stress disorder symptoms to physical health and depression that is mediated by sleep quality in officers (N = 193) using data from small- to mid-size police agencies. Results revealed that sleep problems served as a mediator between posttraumatic stress disorder hyperarousal and avoidance symptoms and health outcomes, that the trauma types are related to different posttraumatic stress disorder symptoms, and that complicated relationships exist between the study variables. In addition, the results indicated that approximately 25% of our sample displayed probable partial posttraumatic stress disorder or probable full posttraumatic stress disorder, causing substantial functional impairment. Suggestions for improving officer health and performance in the field are provided. Specifically, it appears that interventions designed to address posttraumatic stress disorder hyperarousal symptoms related to personal life threat and the posttraumatic stress disorder avoidance symptoms related to the witnessing of human suffering may maximize officer sleep quality and ultimately overall wellness. In particular, mindfulness-based interventions are well suited for addressing these symptom clusters.

Cardiorespiratory Functioning in Youth with Persistent Post-Concussion Symptoms: A Pilot Study

Dysregulation of the autonomic nervous system (ANS) may play an important role in the development and maintenance of persistent post-concussive symptoms (PPCS). Post-injury breathing dysfunction, which is influenced by the ANS, has not been well-studied in youth. This study evaluated cardiorespiratory functioning at baseline in youth patients with PPCS and examined the relationship of cardiorespiratory variables with neurobehavioral outcomes. Participants were between the ages of 13-25 in two groups: (1) Patients with PPCS (concussion within the past 2-16 months; n = 13) and (2) non-injured controls (n = 12). Capnometry was used to obtain end-tidal CO2 (EtCO2), oxygen saturation (SaO2), respiration rate (RR), and pulse rate (PR) at seated rest. PPCS participants exhibited a reduced mean value of EtCO2 in exhaled breath (M = 36.3 mmHg, SD = 2.86 mmHg) and an altered inter-correlation between EtCO2 and RR compared to controls. Neurobehavioral outcomes including depression, severity of self-reported concussion symptoms, cognitive catastrophizing, and psychomotor processing speed were correlated with cardiorespiratory variables when the groups were combined. Overall, results from this study suggest that breathing dynamics may be altered in youth with PPCS and that cardiorespiratory outcomes could be related to a dimension of neurobehavioral outcomes associated with poorer recovery from concussion.

The Interplay between Oxidative Stress, Exercise, and Pain in Health and Disease: Potential Role of Autonomic Regulation and Epigenetic Mechanisms

Oxidative stress can be induced by various stimuli and altered in certain conditions, including exercise and pain. Although many studies have investigated oxidative stress in relation to either exercise or pain, the literature presents conflicting results. Therefore, this review critically discusses existing literature about this topic, aiming to provide a clear overview of known interactions between oxidative stress, exercise, and pain in healthy people as well as in people with chronic pain, and to highlight possible confounding factors to keep in mind when reflecting on these interactions. In addition, autonomic regulation and epigenetic mechanisms are proposed as potential mechanisms of action underlying the interplay between oxidative stress, exercise, and pain. This review highlights that the relation between oxidative stress, exercise, and pain is poorly understood and not straightforward, as it is dependent on the characteristics of exercise, but also on which population is investigated. To be able to compare studies on this topic, strict guidelines should be developed to limit the effect of several confounding factors. This way, the true interplay between oxidative stress, exercise, and pain, and the underlying mechanisms of action can be revealed and validated via independent studies.

Autonomic dysfunction in posttraumatic stress disorder indexed by heart rate variability: a meta-analysis

BACKGROUND

Changes in autonomic nervous system (ANS) function have been observed in a variety of psychological disorders, including posttraumatic stress disorder (PTSD). Analysis of heart rate variability (HRV) provides insight into the functioning of the ANS. Previous research on PTSD found lower HRV in PTSD patients compared to controls, indicating altered sympathetic and parasympathetic activity, but findings are inconsistent. The purpose of this meta-analysis was to examine differences in HRV indices between individuals with PTSD and healthy controls at baseline and during stress.

METHODS

The included primary studies present an aggregate of studies analyzing different HRV indices. Examined HRV indices were standard deviation of the normalized NN-intervals (SDNN), root mean square of successive differences (RMSSD), low-frequency (LF) and high-frequency (HF) spectral components, LF/HF ratio, and heart rate (HR). Moderating effects of study design, HRV and PTSD assessment, and sample characteristics were examined via subgroup-analyses and meta-regressions.

RESULTS

Random-effects meta-analyses for HRV parameters at rest revealed significant group differences for RMSSD and HF-HRV, suggesting lower parasympathetic activity in PTSD. The aggregated effect size for SDNN was medium, suggesting diminished total variability in PTSD. A small effect was found for LF-HRV. A higher LF/HF ratio was found in the PTSD sample as compared to controls. Individuals with PTSD showed significantly higher HR. During stress, individuals with PTSD showed higher HR and lower HF-HRV, both indicated by small effect sizes.

CONCLUSIONS

Findings suggest that PTSD is associated with ANS dysfunction.

Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome

BACKGROUND

Persistent Sport-Related Post-Concussion Syndrome is often diagnosed with any type of prolonged PCS symptoms. However, there are not specific diagnostic criteria for PPCS such that misdiagnosis often occurs. Further, the signs and symptoms of PCS overlap with other common illnesses such as depression, anxiety, migraines, ADHD and others. Misdiagnosis may lead to less than efficacious treatment, resulting in prolonged symptoms.

OBJECTIVE

This article will review relevant evidence-based literature on PCS, pointing out the lack of a systemic diagnostic framework. It will also provide evidence that highlights the multiple conflicting findings in the literature. This article will posit the BioPsychoSocial framework as the best diagnostic framework for understanding the impact of concussions on the person and to generate individualized and personal interventions.

METHODS

A narrative review of sport concussion-related articles was conducted, after extensive searches of relevant and non-relevant literature by each author, as well as articles recommended by colleagues. Articles varied from American Academy of Neurology Class I to IV for evaluation and critique. Class IV articles were reviewed, as there is much public misconception regarding sport and other concussion treatment that needed identification and discussion.

RESULTS

Articles reviewed varied by quality of research design and methodology. Multiple symptoms, recovery patterns and rehabilitation treatment approaches are purported in the sport-related concussion literature. Current consensus data as well as the mixed and contradictory findings were explored.

CONCLUSIONS

Persistent Sport-Related Post-Concussion Syndrome is a topic of great interest to both professionals and the general public. There is much misunderstanding about the etiology, causation, diagnostic formulations, symptom presentation, prolonging factors and treatment involved in this syndrome. This article posits an individualized multi-system diagnostic formulation, examining all relevant factors, as generating the best interventions for neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome.

Heart and Brain Interaction of Psychiatric Illness: A Review Focused on Heart Rate Variability, Cognitive Function, and Quantitative Electroencephalography

Heart rate variability (HRV) reflects beat-to-beat variability in the heart rate due to the dynamic interplay of the sympathetic and parasympathetic nervous systems. HRV is considered an index of the functional status of the autonomic nervous system. A decrease in HRV is thus observed in individuals with autonomic dysfunction. Abnormal HRV has been reported in a range of mental disorders. In this review, we give an overview of HRV in patients with major depressive disorder (MDD), schizophrenia, and posttraumatic stress disorder (PTSD), one of whose core symptoms is cognitive dysfunction. The association between HRV and cognitive function is highlighted in this review. This review consists of three main sections. In the first section, we examine how HRV in patients with MDD, schizophrenia, and PTSD is characterized, and how it is different when compared to that in healthy controls. In the second section, beyond the heart itself, we discuss the intimate connection between the heart and the brain, focusing on how HRV interacts with quantitative electroencephalography (qEEG) in the context of physiological changes in the sleep cycle. Lastly, we finish the review with the examination of the association between HRV and cognitive function. The overall findings indicate that the reduction in HRV is one of main manifestations in MDD, schizophrenia, and PTSD, and also more generally HRV is closely linked to the change in qEEG and also to individual differences in cognitive performance.

Companion Dog Foster Caregiver Program for Older Veterans at the VA Maryland Health Care System: A Feasibility Study

Veterans experience mental health conditions at a disproportionate rate compared to their civilian counterparts, and approximately 60% of older veterans who receive their care through the United States Department of Veterans Affairs (VA) do not meet physical activity (PA) recommendations. We tested the Veterans as Foster Ambassadors program at the VA Maryland Health Care System to examine whether fostering a companion dog would improve PA and function, heart rate variability (HRV), balance, and quality of life (QOL) in older veterans. Participants wore an accelerometer for ≥10 days during each phase (30 day baseline vs. 60 day foster period) to measure daily PA (n = 4). Six-minute walk (6MW) and balance testing (n = 4) and 24 h heart rate (HR) and HRV (n = 2) were determined at baseline and during the foster period. Compared to baseline, there were significant increases in (a) distance during the 6MW, (b) daily steps, and (c) time spent in moderate activity during the foster period. 24 h HR decreased and time- and frequency-domain measures of HRV significantly increased in a veteran with post-traumatic stress disorder during the foster period compared to baseline. All veterans offered positive feedback about the program and indicated that it was beneficial to them. The results from this pilot study provide evidence that fostering a companion dog can improve PA, health, and QOL in older veterans. Future research conducted with a larger sample size to validate the results is warranted.

The association between PTSD and cardiovascular disease and its risk factors in male veterans of the Iraq/Afghanistan conflicts: a systematic review

Military personnel with Post-Traumatic Stress Disorder (PTSD) can experience high levels of mental and physical health comorbidity, potentially indicating a high level of functional impairment that can impact on both military readiness and later ill-health. There is strong evidence to implicate PTSD as a contributory factor to Cardiovascular Disease (CVD) among serving personnel and veterans. This systematic review focusses on the association between PTSD and cardiovascular disease/risk factors in male, military serving and ex-serving personnel who served in the Iraq/Afghanistan conflicts. PUBMED, MEDLINE, PILOTS, EMBASE, PSYCINFO, and PSYCARTICLES were searched using PRISMA guidelines. Three hundred and forty-three records were identified, of which 20 articles were selected. PTSD was positively associated with the development of CVD, specifically circulatory diseases, including hypertension. PTSD was also positively associated with the following risk factors: elevated heart rate, tobacco use, dyslipidaemia, and obesity. Conflicting data is presented regarding heart rate variability and inflammatory markers. Future studies would benefit from a standardized methodological approach to investigating PTSD and physical health manifestations. It is suggested that clinicians offer health advice for CVD at an earlier age for ex-/serving personnel with PTSD.

Impact of PTSD on post-concussive symptoms, neuropsychological functioning, and pain in post-9/11 veterans with mild traumatic brain injury

Prior work suggested that post-traumatic stress disorder (PTSD) worsens post-concussive symptoms (PCS), neuropsychological functioning, and pain-related outcomes in post-9/11 veterans. However, the impact of PTSD in the context of mild traumatic brain injury (mTBI) is not entirely clear. We evaluated possible differences among veterans with deployment-related mTBI with and without PTSD, and a comparison group. We hypothesized that veterans with comorbid mTBI and PTSD would report more PCS, perform worse on neuropsychological tasks, and report greater pain intensity and maladaptive pain coping relative to those without PTSD. Ninety (15 female, 75 male) post-9/11 veterans completed measures of psychiatric functioning, PCS, deployment-related mTBI, pain intensity, pain coping, and a brief neuropsychological evaluation. Veterans with comorbid mTBI and PTSD reported significantly higher PCS across domains, and greater pain intensity and maladaptive coping. They also performed more poorly on measures of recall, but not on measures of attention, encoding, or executive functioning. Findings suggest that PTSD results in greater PCS in the context of mTBI, and is associated with greater pain catastrophizing, worse recall, greater pain intensity, and greater illness-focused coping than in mTBI alone. PCS symptoms, recall, and pain coping may be of clinical importance for post-9/11 veterans with the "polytrauma triad."

Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review

BACKGROUND

Recent evidence suggests that autonomic nervous dysfunction may be one of many potential factors contributing to persisting post-concussion symptoms.

OBJECTIVE

This is the first systematic review to explore the impact of concussion on multiple aspects of autonomic nervous system functioning.

METHODS

The methods employed are in compliance with the American Academy of Neurology (AAN) and PRISMA standards. Embase, MEDLINE, PsychINFO, and Science Citation Index literature searches were performed using relevant indexing terms for articles published prior to the end of December 2016. Data extraction was performed by two independent groups, including study quality indicators to determine potential risk for bias according to the 4-tiered classification scheme of the AAN.

RESULTS

Thirty-six articles qualified for inclusion in the analysis. Only three studies (one Class II and two Class IV) did not identify anomalies in measures of ANS functioning in concussed populations.

CONCLUSIONS

The evidence supports the conclusion that it is likely that concussion causes autonomic nervous system anomalies. An awareness of this relationship increases our understanding of the physical impact of concussion, partially explains the overlap of concussion symptoms with other medical conditions, presents opportunities for further research, and has the potential to powerfully inform treatment decisions.

A Review of Chronic Pain and Cognitive, Mood, and Motor Dysfunction Following Mild Traumatic Brain Injury: Complex, Comorbid, and/or Overlapping Conditions?

Mild traumatic brain injury (mTBI) is commonly encountered in clinical practice. While the cognitive ramifications of mTBI are frequently described in the literature, the impact of mTBI on emotional, sensory, and motor function is not as commonly discussed. Chronic pain is a phenomenon more prevalent among patients with mTBI compared to those with moderate or severe traumatic brain injury. Chronic pain can become a primary disorder of the central nervous system (CNS) expressed as widespread pain, and cognitive, mood, and movement dysfunction. Shared mechanisms across chronic pain conditions can account for how pain is generated and maintained in the CNS, irrespective of the underlying structural pathology. Herein, we review the impact of mTBI on cognitive, emotional, sensory, and motor domains, and the role of pain as an important confounding variable in patient recovery and dysfunction following mTBI.

Alcohol Use Disorder Moderates the Effect of Age on Heart Rate Variability in Veterans With Posttraumatic Stress Disorder

Research on heart rate variability (HRV) in posttraumatic stress disorder (PTSD) and comorbid alcohol use disorder (AUD) is limited despite its use as a biomarker of both disorders. This study examined whether AUD comorbidity contributes an additive effect on HRV for veterans with PTSD. HRV was assessed in 70 male Operation Enduring Freedom/Operation Iraqi Freedom veterans with PTSD, including 32 with co-occurring AUD. Mean HRV values for both groups were below the mean for healthy adults, but additive effects of PTSD and AUD on HRV were not observed. Consistent with prior studies, hierarchical regressions showed that HRV decreased with age in the PTSD-only group. However, HRV increased slightly with age among veterans with both PTSD and AUD. This interaction remained significant after controlling for common HRV covariates. These findings support HRV as a biomarker of PTSD and extend research by demonstrating the complex relationship between PTSD and HRV in the context of co-occurring AUD.

Heart rate-based window segmentation improves accuracy of classifying posttraumatic stress disorder using heart rate variability measures

OBJECTIVE

Heart rate variability (HRV) characterizes changes in autonomic nervous system function and varies with posttraumatic stress disorder (PTSD). In this study we developed a classifier based on heart rate (HR) and HRV measures, and improved classifier performance using a novel HR-based window segmentation.

APPROACH

Single-channel ECG data were collected from 23 subjects with current PTSD, and 25 control subjects with no history of PTSD over 24 h. RR intervals were derived from these data, cleaned, and used to calculate HR and HRV metrics. These metrics were used as features in a logistic regression classifier. Performance was assessed via repeated random sub-sampling validation. To reduce noise and activity-related effects, we calculated features from five non-overlapping ten-minute quiescent segments of RR intervals defined by lowest HR, as well as random ten-minute segments as a control.

MAIN RESULTS

Using a combination of the four most predictive features derived from quiescent segments we achieved a median area under the receiver operating curve (AUC) of 0.86 on out-of-sample test set data. This was significantly higher than the AUC using 24 h of data (0.72) or random segments (0.67).

SIGNIFICANCE

These results demonstrate our segmentation approach improves the classification of PTSD from HR and HRV measures, and suggest the potential for tracking PTSD illness severity via objective physiological monitoring. Future studies should prospectively evaluate if classifier output changes significantly with worsening or effective treatment of PTSD.

Posttraumatic stress disorder symptomatology in the course of allogeneic HSCT: a prospective study

PURPOSE

Despite the life-threatening character of allogeneic hematopoietic stem cell transplantation (allogeneic HSCT), very few longitudinal research exists on posttraumatic stress disorder (PTSD) symptomatology in this patient group. We investigated prevalence, temporal course and predictors of PTSD symptomatology in this population.

METHODS

Patients were assessed before conditioning (T0), 100 days (T1), and 12 months after HSCT (T2). PTSD symptomatology was measured with the PTSD Checklist-Civilian Version. We conducted multilevel modeling and multiple regression analyses.

RESULTS

Two hundred thirty-nine patients participated at baseline, 150 at T1, and 102 at T2. Up to 15 % met the criteria for PTSD at least once during the course of assessment. Fifty-two percent showed diagnostic relevant levels of intrusion, 30 % of avoidance, and 33 % of arousal at least once. Apart from arousal, which increased between T0 and T1 (γ = 0.56, p = 0.03), no other severity score significantly differed between time points. Being impaired by pain (γ = 2.89, p < 0.01), pain level (γ = 0.63, p = 0.02), and being female (γ = 3.81, p < 0.01) emerged as significant predictors of PTSD symptomatology when taking into account all time points. Acute plus chronic graft-versus-host-disease and longer hospital stay predicted PTSD symptomatology at T2 (γ = 3.39, p = 0.04; γ = 0.1, p = 0.03).

CONCLUSIONS

A considerable number of patients undergoing allogeneic HSCT met the criteria for PTSD. PTSD symptomatology is prominent at all assessment points. Burden of pain, being female, and medical complications are risk factors for elevated levels of PTSD symptomatology.

IMPLICATIONS FOR CANCER SURVIVORS

Psychological support should be offered not only after treatment but also in the long-term and even before HSCT. Professionals should be aware of the psychological consequences accompanied by pain and complications.

Distinctive cardiac autonomic dysfunction following stress exposure in both sexes in an animal model of PTSD

It is unclear whether the poor autonomic flexibility or dysregulation observed in patients with posttraumatic stress disorder (PTSD) represents a pre-trauma vulnerability factor or results from exposure to trauma. We used an animal model of PTSD to assess the association between the behavioral response to predator scent stress (PSS) and the cardiac autonomic modulation in male and female rats. The rats were surgically implanted with radiotelemetry devices to measure their electrocardiograms and locomotor activity (LMA). Following baseline telemetric monitoring, the animals were exposed to PSS or sham-PSS. Continuous telemetric monitoring (24h/day sampling) was performed over the course of 7days. The electrocardiographic recordings were analyzed using the time- and frequency-domain indexes of heart rate variability (HRV). The behavioral response patterns were assessed using the elevated plus maze and acoustic startle response paradigms for the retrospective classification of individuals according to the PTSD-related cut-off behavioral criteria. During resting conditions, the male rats had significantly higher heart rates (HR) and lower HRV parameters than the female rats during both the active and inactive phases of the daily cycle. Immediately after PSS exposure, both the female and male rats demonstrated a robust increase in HR and a marked drop in HRV parameters, with a shift of sympathovagal balance towards sympathetic predominance. In both sexes, autonomic system habituation and recovery were selectively inhibited in the rats whose behavior was extremely disrupted after exposure to PSS. However, in the female rats, exposure to the PSS produced fewer EBR rats, with a more rapid recovery curve than that of the male rats. PSS did not induce changes to the circadian rhythm of the LMA. According to our results, PTSD can be conceptualized as a disorder that is related to failure-of-recovery mechanisms that impede the restitution of physiological homeostasis.

Sleep, Sleep Disorders, and Mild Traumatic Brain Injury. What We Know and What We Need to Know: Findings from a National Working Group

Disturbed sleep is one of the most common complaints following traumatic brain injury (TBI) and worsens morbidity and long-term sequelae. Further, sleep and TBI share neurophysiologic underpinnings with direct relevance to recovery from TBI. As such, disturbed sleep and clinical sleep disorders represent modifiable treatment targets to improve outcomes in TBI. This paper presents key findings from a national working group on sleep and TBI, with a specific focus on the testing and development of sleep-related therapeutic interventions for mild TBI (mTBI). First, mTBI and sleep physiology are briefly reviewed. Next, essential empirical and clinical questions and knowledge gaps are addressed. Finally, actionable recommendations are offered to guide active and efficient collaboration between academic, industry, and governmental stakeholders.

Sleep Quality and Reexperiencing Symptoms of PTSD Are Associated With Current Pain in U.S. OEF/OIF/OND Veterans With and Without mTBIs

Pain, a debilitating condition, is frequently reported by U.S. veterans returning from Afghanistan and Iraq. This study investigated how commonly reported clinical factors were associated with pain and whether these associations differed for individuals with a history of chronic pain. From the Boston metropolitan area, 171 veterans enrolled in the Veterans Affairs Center of Excellence were assessed for current posttraumatic stress disorder (PTSD) symptom severity, current mood and anxiety diagnoses, lifetime traumatic brain injury, combat experiences, sleep quality, and alcohol use. Hierarchical regression models were used to determine the association of these conditions with current pain. Average pain for the previous 30 days, assessed with the McGill Pain Questionnaire, was 30.07 out of 100 (SD = 25.43). Sleep quality, PTSD symptom severity, and alcohol use were significantly associated with pain (R(2) = .24), as were reexperiencing symptoms of PTSD (R(2) = .25). For participants with a history of chronic pain (n = 65), only PTSD symptoms were associated with pain (R(2) = .19). Current pain severity was associated with increased PTSD severity (notably, reexperiencing symptoms), poor sleep quality, and increased alcohol use. These data support the hypothesis that PTSD symptoms influence pain, but suggest that problems with sleep and alcohol use may exacerbate the relationship.

Prevalence of, risk factors for, and consequences of posttraumatic stress disorder and other mental health problems in military populations deployed to Iraq and Afghanistan

This review summarizes the epidemiology of posttraumatic stress disorder (PTSD) and related mental health problems among persons who served in the armed forces during the Iraq and Afghanistan conflicts, as reflected in the literature published between 2009 and 2014. One-hundred and sixteen research studies are reviewed, most of which are among non-treatment-seeking US service members or treatment-seeking US veterans. Evidence is provided for demographic, military, and deployment-related risk factors for PTSD, though most derive from cross-sectional studies and few control for combat exposure, which is a primary risk factor for mental health problems in this cohort. Evidence is also provided linking PTSD with outcomes in the following domains: physical health, suicide, housing and homelessness, employment and economic well-being, social well-being, and aggression, violence, and criminality. Also included is evidence about the prevalence of mental health service use in this cohort. In many instances, the current suite of studies replicates findings observed in civilian samples, but new findings emerge of relevance to both military and civilian populations, such as the link between PTSD and suicide. Future research should make effort to control for combat exposure and use longitudinal study designs; promising areas for investigation are in non-treatment-seeking samples of US veterans and the role of social support in preventing or mitigating mental health problems in this group.

Antiepileptic drug prescribing patterns in Iraq and Afghanistan war veterans with epilepsy

OBJECTIVE

We examined patterns of antiepileptic drug (AED) use in a cohort of Iraq/Afghanistan war veterans (IAVs) who were previously identified as having epilepsy. We hypothesized that clinicians would be more likely to prescribe newer AEDs and would select specific AEDs to treat seizures based on patient characteristics including gender and comorbidities.

METHODS

From the cohort of IAVs previously identified with epilepsy between fiscal years 2009 and 2010, we selected those who received AEDs from the Veterans Health Administration in FY2010. Regimens were classified as monotherapy or polytherapy, and specific AED use was examine overall and by gender. Multivariable logistic regression examined associations of age; gender; race/ethnicity; medical, psychiatric, and neurological comorbidities; and receipt of neurology specialty care associated with the six most commonly used AEDs.

RESULTS

Among 256,284 IAVs, 2123 met inclusion criteria (mean age: 33years; 89% men). Seventy-two percent (n=1526) received monotherapy, most commonly valproate (N=425) and levetiracetam (n=347). Sixty-one percent of those on monotherapy received a newer AED (levetiracetam, topiramate, lamotrigine, zonisamide, oxcarbazepine). Although fewer women than men received valproate, nearly 90% (N=45) were of reproductive age (≤45years). Antiepileptic drug prescribing patterns were associated with posttraumatic stress disorder, bipolar disorder, cerebrovascular disease, dementia/cognitive impairment, headache, and receipt of neurological specialty care (all p<0.01).

SIGNIFICANCE

In this cohort of veterans with epilepsy, most received AED monotherapy and newer AEDs. Prescribing patterns were different for men and women. The patterns observed between AEDs and neurological/psychiatric comorbidities suggest that clinicians are practicing rational prescribing.

Characteristics and Outcomes of Women Veterans Undergoing Cardiac Catheterization in the Veterans Affairs Healthcare System

Background—

The number of women veterans is increasing, yet little is known about their cardiovascular risk factors, coronary anatomy, cardiac treatments, and outcomes after cardiac catheterization. Prior studies have shown that nonveteran women have more risk factors, receive less aggressive treatment, and have worse outcomes, despite having less obstructive coronary artery disease than men. Whether these differences exist among women veterans in the veterans affairs healthcare system is unknown.

Methods and Results—

Data on 85 936 veterans (3181 women) undergoing initial cardiac catheterization between October 1, 2007, and September 30, 2012, were examined using the national veterans affairs Clinical Assessment Reporting and Tracking (CART) Program. Sex differences in demographics, indications, coronary anatomy, cardiac treatments, and outcomes were analyzed. Women veterans were younger (56.9 versus 63.0 years, P <0.0001) with fewer traditional cardiovascular risk factors, but with more obesity, depression, and posttraumatic stress disorder than men. Women had lower rates of obstructive coronary artery disease than men (22.6% versus 53.3%). Rates of procedural complications were similar in both genders. Adjusted outcomes at 1 year showed women had lower mortality (hazard ratio, 0.74; confidence interval, 0.60–0.92) and less all-cause rehospitalization (hazard ratio, 0.87; confidence interval, 0.82–0.93), but no difference in rates of unplanned percutaneous coronary intervention.

Conclusions—

Women veterans undergoing catheterization are younger, have more obesity, depression, and posttraumatic stress disorder, less obstructive coronary artery disease, and similar long-term outcomes, compared with men. These findings suggest a significant portion of women veterans may have chest pain not attributable to obstructive coronary artery disease. Further research into possible causes, such as endothelial dysfunction or concurrent psychological comorbidities, is needed.

Effect of Symptom Over-Reporting on Heart Rate Variability in Veterans With Posttraumatic Stress Disorder

Physiological assessment of posttraumatic stress disorder (PTSD) presents an additional avenue for evaluating the severity of PTSD symptoms. We investigated whether the presence of a high number of uncommon symptoms attenuated the relation between self-reported PTSD symptoms and heart rate variability (HRV). Participants were 115 veterans from Operation Iraqi Freedom and Operation Enduring Freedom with or without PTSD. Symptom over-report was assessed using the Miller Forensic Assessment of Symptoms Test (M-FAST). Participants completed the Clinician-Administered PTSD Scale and M-FAST and underwent physiological assessment to determine HRV. These data were then entered into a hierarchical linear regression equation to test the moderating effect of over-reporting on the relation between PTSD symptom severity and HRV. The result of this analysis failed to demonstrate a significant moderating effect of over-reporting on the PTSD and HRV relation. HRV was a significant predictor of PTSD symptom severity, and this relation did not differ across levels of over-reporting. These findings did not support the hypothesis that over-reporting would attenuate the relation between PTSD and HRV. Clinical and research implications and directions for future investigation are discussed.

Heart rate variability interventions for concussion and rehabilitation

The study of heart rate variability (HRV) has emerged as an essential component of cardiovascular health, as well as a physiological mechanism by which one can increase the interactive communication between the cardiac and the neurocognitive systems (i.e., the body and the brain). It is well-established that lack of HRV implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal HRV has been associated with good cardiovascular health, autonomic nervous system (ANS) control, emotional regulation, and enhanced neurocognitive processing. In addition to health benefits, optimal HRV has been shown to improve neurocognitive performance by enhancing focus, visual acuity and readiness, and by promoting emotional regulation needed for peak performance. In concussed athletes and soldiers, concussions not only alter brain connectivity, but also alter cardiac functioning and impair cardiovascular performance upon exertion. Altered sympathetic and parasympathetic balance in the ANS has been postulated as a critical factor in refractory post concussive syndrome (PCS). This article will review both the pathological aspects of reduced HRV on athletic performance, as well as the cardiovascular and cerebrovascular components of concussion and PCS. Additionally, this article will review interventions with HRV biofeedback (HRV BFB) training as a promising and underutilized treatment for sports and military-related concussion. Finally, this article will review research and promising case studies pertaining to use of HRV BFB for enhancement of cognition and performance, with applicability to concussion rehabilitation.

Nurses' knowledge of pain management for patients with combat-related traumatic brain injuries on rehabilitation units

PURPOSE

The purpose of this project was to survey nurses' knowledge of pain management for patients with combat-related traumatic brain injuries (TBI).

DESIGN/METHODS

A survey was used to collect data regarding nurses' knowledge of pain assessment and management for patients with combat-related TBI. Nurses were invited to participate in the study via email and provided with a link to the electronic survey.

FINDINGS

Twenty-five surveys were returned (52% response rate). A total of 76% of nurse respondents perceived that TBI patients over report pain intensity. Only 40% of nurses were able to correctly identify the appropriate medication to treat migraine-type headache pain in TBI patients.

CONCLUSION

This study identified gaps in knowledge regarding pain management for patients with combat related TBIs.

CLINICAL RELEVANCE

Nurses need additional education regarding common pain syndromes, available treatments, and a better understanding of addiction in order to provide optimal care to these patients.

They know their trauma by heart: an assessment of psychophysiological failure to recover in PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) develops following exposure to atraumatic event and is characterized by persistent intense reactivity to trauma related cues. Equally important, but less studied, is the failure to restore physiological homeostasis after these excessive reactions. This study investigates psychophysiological markers of sustained cardiac activity after exposure to reminders of traumatic event in PTSD patients.

METHODS

Participants passively listened to neutral and personal traumatic event while electrocardiogram was continuously recorded. Heart rate (HR) and heart rate variability (HRV) were analyzed in 19 PTSD patients and 16 trauma-exposed controls.

RESULTS

Both PTSD patients and trauma exposed controls exhibited a significant increase in HR to the exposure of their personal trauma. PTSD patients sustained the increase of HR while controls recovered to basal levels. In PTSD patients, sustained HR was positively associated with re-experiencing symptoms. The PTSD group also showed a reduced HRV (a measure of parasympathetic influence on the heart) during personal trauma exposure and lack of recovery.

LIMITATIONS

The sample size was small and PTSD patients were under medication.

CONCLUSIONS

Our findings provide an experimental account of the failure of PTSD patients to exhibit physiological recovery after exposure to trauma-related stimuli. PTSD patients exhibited a sustained tachycardia with attenuation of HRV that persisted even after cessation of the stressor. Re-experiencing symptoms facilitated engagement in the trauma cues, suggesting that, in their daily-life, patients most likely present repeated episodes of sustained over-reactivity, which may underpin the emotional dysregulation characteristic of PTSD.

Heart rate variability biofeedback, executive functioning and chronic brain injury

PRIMARY OBJECTIVE

To determine if individuals with brain injury can modify heart rate variability (HRV) through biofeedback and, if so, enhance its pattern to improve emotional regulation and problem-solving ability.

DESIGN

A quasi-experimental design with repeated measures was employed. Thirteen individuals aged 23-63 years with severe brain injury (13-40 years post-onset) participating in a community-based programme were enrolled.

MAIN OUTCOMES

Response-to-treatment was measured with HRV indices, Behavior Rating Inventory of Executive Function (BRIEF-A-Informant) and attention/problem-solving tests.

RESULTS

At post-treatment, HRV indices (Low Frequency/High Frequency [LF/HF] and coherence ratio) increased significantly. Increased LF/HF values during the second-half of a 10-minute session were associated with higher attention scores. Participants who scored better (by scoring lower) in informant ratings at pre-treatment had highest HRV scores at post-treatment. Accordingly, at post-treatment, families' ratings of participants' emotional control correlated with HRV indices; staffs' ratings of participants' working memory correlated with participants' HRV indices. Self-ratings of the BRIEF-A Task Monitoring scale at post-treatment correlated with family ratings at pre-treatment and post-treatment.

CONCLUSIONS

Results demonstrate an association between regulation of emotions/cognition and HRV training. Individuals with severe, chronic brain injury can modify HRV through biofeedback. Future research should evaluate the efficacy of this approach for modifying behavioural problems.

Preliminary validation of the Defense and Veterans Pain Rating Scale (DVPRS) in a military population

BACKGROUND

The Army Surgeon General released the Pain Management Task Force final report in May 2010. Among military providers, concerns were raised that the standard numeric rating scale (NRS) for pain was inconsistently administered and of questionable clinical value. In response, the Defense and Veterans Pain Rating Scale (DVPRS) was developed.

METHODS

The instrument design integrates pain rating scale features to improve interpretability of incremental pain intensity levels, and to improve communication and documentation across all transitions of care. A convenience sample of 350 inpatient and outpatient active duty or retired military service members participated in the study at Walter Reed Army Medical Center. Participants completed the five-item DVPRS-one pain intensity NRS with and without word descriptors presented in random order and four supplemental items measuring general activity, sleep, mood, and level of stress and the Brief Pain Inventory seven interference items. Using systematic sampling, a random sample was selected for a word descriptor validation procedure matching word phases to corresponding pain intensity on the NRS.

RESULTS

Parallel forms reliability and concurrent validity testing demonstrated a robust correlation. When the DVPRS was presented with the word descriptors first, the correlation between the two ratings was slightly higher, r = 0.929 (N = 171; P < 0.001), than ordering first without the descriptors, r = 0.882 (N = 177; P < 0.001). Intraclass correlation coefficient was 0.943 showing excellent alignment of word descriptors by respondents (N = 42), matching them correctly with pain level.

CONCLUSIONS

The DVPRS tool demonstrated acceptable psychometric properties in a military population.