Traumatic brain injury, neuroinflammation, and post-traumatic headaches

Phloroglucinol Derivatives Exert Anti-Inflammatory Effects and Attenuate Cognitive Impairment in LPS-Induced Mouse Model

Neuroinflammation is an inflammatory immune response that arises in the central nervous system. It is one of the primary causes of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Phloroglucinol (PG) is a natural product contained in extracts of plant, algae and microbe and has been reported to have antioxidant and anti-inflammatory properties. In this study, we synthesized PG derivatives to enhance antioxidant and anti-inflammatory activity. Among PG derivatives, 6 a suppressed pro-oxidative and inflammatory molecule nitric oxide (NO) production more effectively than PG. Moreover, 6 a dose-dependently reduced the expression of proinflammatory cytokines such as IL-6, IL-1β, TNF-α, and NO producing enzyme iNOS in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Additionally, we confirmed that 6 a alleviated cognitive impairment and glial activation in mouse model of LPS-induced neuroinflammation. These findings suggest that novel PG derivative, 6 a, is a potential treatment for neurodegenerative diseases.

Hypothalamic-Pituitary-Adrenal (HPA) Axis: Unveiling the Potential Mechanisms Involved in Stress-Induced Alzheimer's Disease and Depression

The hypothalamic-pituitary-adrenal (HPA) axis plays a pivotal role in the body's response to stress, orchestrating the release of glucocorticoids. In chronic scenarios, these glucocorticoids contribute to various neurological disorders, including Alzheimer's disease (AD) and depression. This abstract explores the potential mechanisms through which HPA axis dysregulation links stress-induced pathways to the pathogenesis of AD and subsequent depression. Chronic stress triggers prolonged HPA axis activation, resulting in elevated cortisol levels, which can lead to hippocampal atrophy, synaptic dysfunction, and neuroinflammation, recognized as key pathological features of AD. These alterations impair cognitive function and may exacerbate amyloid-beta plaque formation and tau hyperphosphorylation, hallmarks of AD. Concurrently, persistent cortisol elevation affects the prefrontal cortex and limbic structures, contributing to depressive symptoms. The interplay between chronic stress, HPA axis dysregulation, and neuroinflammation is crucial in understanding the comorbidity of AD and depression. Unveiling these mechanisms provides insights into potential therapeutic targets aimed at modulating the HPA axis and reducing stress-induced neurodegeneration, offering a dual benefit in managing both AD and depression. Further research is essential to elucidate the precise molecular pathways and develop effective interventions to mitigate the impact of chronic stress on brain health.

Susceptibility to Hepatotoxic Drug-Induced Liver Injury Increased After Traumatic Brain Injury in Mice

The early stages of brain injury can induce acute liver injury, which can be recovered in the short term. Continued medication treatment during hospitalization for brain injury alleviates the prognosis and contributes to a high incidence of drug-induced liver injury (DILI). We hypothesize that there is an interaction between changes in the hepatic environment after brain injury and liver injury produced by intensive drug administration, leading to an upregulation of the organism's sensitivity to DILI. In this study, mice models of TBI were established by controlled cortical impact (CCI) and models of DILI were constructed by acetaminophen (APAP). All mice were divided into four groups: Sham, TBI, APAP, and TBI+APAP, and related liver injury indicators in liver and serum were detected by Western blot, Quantitative real-time PCR (qRT-PCR), and immunohistochemical staining. The results suggested that liver injury induced in the early stages of brain injury recovered in 3 days, but this state could still significantly aggravate DILI, represented by higher liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), oxidative stress (increase in malondialdehyde [MDA] concentration and deregulation of glutathione [GSH] and superoxide dismutase [SOD] activities), inflammatory response (activation of the HMGB1/TLR4/NF-κB signaling pathway, and increased messenger RNA [mRNA] and protein levels of pro-inflammatory cytokines including tumor necrosis factor alpha [TNF-α], interleukin [IL]-6, and IL-1β), and apoptosis (TUNEL assay, upregulation of Bax protein and deregulation of Bcl-2 protein). In summary, our results suggested that TBI is a potential susceptibility factor for DILI and exacerbates DILI.

Posttraumatic Headache

OBJECTIVE

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

LATEST DEVELOPMENTS

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

ESSENTIAL POINTS

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

Longitudinal Associations Between Persistent Post-Concussion Symptoms and Blood Biomarkers of Inflammation and CNS-Injury After Mild Traumatic Brain Injury

The aim of our study was to investigate the biological underpinnings of persistent post-concussion symptoms (PPCS) at 3 months following mild traumatic brain injury (mTBI). Patients (n = 192, age 16-60 years) with mTBI, defined as Glasgow Coma Scale (GCS) score between 13 and 15, loss of consciousness (LOC) <30 min, and post-traumatic amnesia (PTA) <24 h were included. Blood samples were collected at admission (within 72 h), 2 weeks, and 3 months. Concentrations of blood biomarkers associated with central nervous system (CNS) damage (glial fibrillary acidic protein [GFAP], neurofilament light [NFL], and tau) and inflammation (interferon gamma [IFNγ], interleukin [IL]-8, eotaxin, macrophage inflammatory protein-1-beta [MIP]-1β, monocyte chemoattractant protein [MCP]-1, interferon-gamma-inducible protein [IP]-10, IL-17A, IL-9, tumor necrosis factor [TNF], basic fibroblast growth factor [FGF]-basic platelet-derived growth factor [PDGF], and IL-1 receptor antagonist [IL-1ra]) were obtained. Demographic and injury-related factors investigated were age, sex, GCS score, LOC, PTA duration, traumatic intracranial finding on magnetic resonance imaging (MRI; within 72 h), and extracranial injuries. Delta values, that is, time-point differences in biomarker concentrations between 2 weeks minus admission and 3 months minus admission, were also calculated. PPCS was assessed with the British Columbia Post-Concussion Symptom Inventory (BC-PSI). In single variable analyses, longer PTA duration and a higher proportion of intracranial findings on MRI were found in the PPCS group, but no single biomarker differentiated those with PPCS from those without. In multi-variable models, female sex, longer PTA duration, MRI findings, and lower GCS scores were associated with increased risk of PPCS. Inflammation markers, but not GFAP, NFL, or tau, were associated with PPCS. At admission, higher concentrations of IL-8 and IL-9 and lower concentrations of TNF, IL-17a, and MCP-1 were associated with greater likelihood of PPCS; at 2 weeks, higher IL-8 and lower IFNγ were associated with PPCS; at 3 months, higher PDGF was associated with PPCS. Higher delta values of PDGF, IL-17A, and FGF-basic at 2 weeks compared with admission, MCP-1 at 3 months compared with admission, and TNF at 2 weeks and 3 months compared with admission were associated with greater likelihood of PPCS. Higher IL-9 delta values at both time-point comparisons were negatively associated with PPCS. Discriminability of individual CNS-injury and inflammation biomarkers for PPCS was around chance level, whereas the optimal combination of biomarkers yielded areas under the curve (AUCs) between 0.62 and 0.73. We demonstrate a role of biological factors on PPCS, including both positive and negative effects of inflammation biomarkers that differed based on sampling time-point after mTBI. PPCS was associated more with acute inflammatory processes, rather than ongoing inflammation or CNS-injury biomarkers. However, the modest discriminative ability of the models suggests other factors are more important in the development of PPCS.

Methylphenidate Ameliorates Behavioural and Neurobiological Deficits in Executive Function for Patients with Chronic Traumatic Brain Injury

(1) Background: Traumatic brain injury (TBI) often results in cognitive impairments, including in visuospatial planning and executive function. Methylphenidate (MPh) demonstrates potential improvements in several cognitive domains in patients with TBI. The Tower of London (TOL) is a visuospatial planning task used to assess executive function. (2) Methods: Volunteers with a history of TBI (n = 16) participated in a randomised, double-blinded, placebo-controlled, fMRI study to investigate the neurobiological correlates of visuospatial planning and executive function, on and off MPh. (3) Results: Healthy controls (HCs) (n = 18) and patients on placebo (TBI-placebo) differed significantly in reaction time (p < 0.0005) and accuracy (p < 0.0001) when considering all task loads, but especially for high cognitive loads for reaction time (p < 0.001) and accuracy (p < 0.005). Across all task loads, TBI-MPh were more accurate than TBI-placebo (p < 0.05) but remained less accurate than HCs (p < 0.005). TBI-placebo substantially improved in accuracy with MPh administration (TBI-MPh) to a level statistically comparable to HCs at low (p = 0.443) and high (p = 0.175) cognitive loads. Further, individual patients that performed slower on placebo at low cognitive loads were faster with MPh (p < 0.05), while individual patients that performed less accurately on placebo were more accurate with MPh at both high and low cognitive loads (p < 0.005). TBI-placebo showed reduced activity in the bilateral inferior frontal gyri (IFG) and insulae versus HCs. MPh normalised these regional differences. MPh enhanced within-network connectivity (between parietal, striatal, insula, and cerebellar regions) and enhanced beyond-network connectivity (between parietal, thalamic, and cerebellar regions). Finally, individual changes in cerebellar-thalamic (p < 0.005) and cerebellar-parietal (p < 0.05) connectivity with MPh related to individual changes in accuracy with MPh. (4) Conclusions: This work highlights behavioural and neurofunctional differences between HCs and patients with chronic TBI, and that adverse differences may benefit from MPh treatment.

Making migraine easier to stomach: the role of the gut-brain-immune axis in headache disorders

BACKGROUND AND PURPOSE

Headache disorders place a significant burden on the healthcare system, being the leading cause of disability in those under 50 years. Novel studies have interrogated the relationship between headache disorders and gastrointestinal dysfunction, suggesting a link between the gut-brain-immune (GBI) axis and headache pathogenesis. Although the exact mechanisms driving the complex relationship between the GBI axis and headache disorders remain unclear, there is a growing appreciation that a healthy and diverse microbiome is necessary for optimal brain health.

METHODS

A literature search was performed through multiple reputable databases in search of Q1 journals within the field of headache disorders and gut microbiome research and were critically and appropriately evaluated to investigate and explore the following; the role of the GBI axis in dietary triggers of headache disorders and the evidence indicating that diet can be used to alleviate headache severity and frequency. The relationship between the GBI axis and post-traumatic headache is then synthesized. Finally, the scarcity of literature regarding paediatric headache disorders and the role that the GBI axis plays in mediating the relationship between sex hormones and headache disorders are highlighted.

CONCLUSIONS

There is potential for novel therapeutic targets for headache disorders if understanding of the GBI axis in their aetiology, pathogenesis and recovery is increased.

Macrophages and microglia in inflammation and neuroinflammation underlying different pain states

Pain is a main symptom in inflammation, and inflammation induces pain via inflammatory mediators acting on nociceptive neurons. Macrophages and microglia are distinct cell types, representing immune cells and glial cells, respectively, but they share similar roles in pain regulation. Macrophages are key regulators of inflammation and pain. Macrophage polarization plays different roles in inducing and resolving pain. Notably, macrophage polarization and phagocytosis can be induced by specialized pro-resolution mediators (SPMs). SPMs also potently inhibit inflammatory and neuropathic pain via immunomodulation and neuromodulation. In this review, we discuss macrophage signaling involved in pain induction and resolution, as well as in maintaining physiological pain. Microglia are macrophage-like cells in the central nervous system (CNS) and drive neuroinflammation and pathological pain in various inflammatory and neurological disorders. Microglia-produced inflammatory cytokines can potently regulate excitatory and inhibitory synaptic transmission as neuromodulators. We also highlight sex differences in macrophage and microglial signaling in inflammatory and neuropathic pain. Thus, targeting macrophage and microglial signaling in distinct locations via pharmacological approaches, including immunotherapies, and non-pharmacological approaches will help to control chronic inflammation and chronic pain.

Multidimensional pain phenotypes after Traumatic Brain Injury

More than 50% of individuals develop chronic pain following traumatic brain injury (TBI). Research suggests that a significant portion of post-TBI chronic pain conditions is neuropathic in nature, yet the relationship between neuropathic pain, psychological distress, and somatosensory function following TBI is not fully understood. This study evaluated neuropathic pain symptoms, psychological and somatosensory function, and psychosocial factors in individuals with TBI (TBI, N = 38). A two-step cluster analysis was used to identify phenotypes based on the Neuropathic Pain Symptom Inventory and Beck's Anxiety Inventory scores. Phenotypes were then compared on pain characteristics, psychological and somatosensory function, and psychosocial factors. Our analyses resulted in two different neuropathic pain phenotypes: (1) Moderate neuropathic pain severity and anxiety scores (MNP-AS, N = 11); and (2) mild or no neuropathic pain symptoms and anxiety scores (LNP-AS, N = 27). Furthermore, the MNP-AS group exhibited greater depression, PTSD, pain severity, and affective distress scores than the LNP-AS group. In addition, thermal somatosensory function (difference between thermal pain and perception thresholds) was significantly lower in the MNP-AS compared to the LNP-AS group. Our findings suggest that neuropathic pain symptoms are relatively common after TBI and are not only associated with greater psychosocial distress but also with abnormal function of central pain processing pathways.

Could the kynurenine pathway be the key missing piece of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) complex puzzle?

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex and debilitating disease with a substantial social and economic impact on individuals and their community. Despite its importance and deteriorating impact, progresses in diagnosis and treatment of ME/CFS is limited. This is due to the unclear pathophysiology of the disease and consequently lack of prognostic biomarkers. To investigate pathophysiology of ME/CFS, several potential pathologic hallmarks have been investigated; however, these studies have failed to report a consistent result. These failures in introducing the underlying reason for ME/CFS have stimulated considering other possible contributing mechanisms such as tryptophan (TRP) metabolism and in particular kynurenine pathway (KP). KP plays a central role in cellular energy production through the production of nicotinamide adenine dinucleotide (NADH). In addition, this pathway has been shown to mediate immune response and neuroinflammation through its metabolites. This review, we will discuss the pathology and management of ME/CFS and provide evidence pertaining KP abnormalities and symptoms that are classic characteristics of ME/CFS. Targeting the KP regulation may provide innovative approaches to the management of ME/CFS.

Neurological Symptoms and Their Associations With Inflammatory Biomarkers in the Chronic Phase Following Traumatic Brain Injuries

BACKGROUND

The underlying biological mechanisms for neurological symptoms following a traumatic brain injury (TBI) remain poorly understood. This study investigated the associations between serum inflammatory biomarkers and neurological symptoms in the chronic phase following moderate to severe TBI.

METHODS

The serum interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, and the tumor necrosis factor [TNF]-α in 72 TBI patients 6 months to 2 years post injury were measured. Neurological symptoms including depression, chronic headache, sleep disturbance, irritability, anxiety, and global neurological disability was assessed. The associations between the biomarkers and the neurological symptoms were assessed using correlation and regression analysis.

RESULTS

It was found that the most common post-injury symptom was sleep disturbance (84.7%), followed by chronic headaches (59.7%), irritability (55.6%), and depression (54.2%). TNF-α was a protective factor for chronic headache (OR = 0.473, 95% CI = 0.235-0.952). IL-6 was positively associated with sleep disturbance (r = 0.274, p = 0.021), while IL-5 and IL-12p70 were negatively associated with the degree of global neurological disability (r = -0.325, p = 0.006; r = -0.319, p = 0.007).

CONCLUSION

This study provides preliminary evidence for the association between chronic inflammation with neurological symptoms following a TBI, which suggests that anti-inflammatory could be a potential target for post-TBI neurological rehabilitation. Further research with larger sample sizes and more related biomarkers are still needed, however, to elucidate the inflammatory mechanisms for this association.

Crosstalk between Microglia and Neurons in Neurotrauma: An Overview of the Underlying Mechanisms

Microglia are the resident immune cells of the brain and play a crucial role in housekeeping and maintaining homeostasis of the brain microenvironment. Upon injury or disease, microglial cells become activated, at least partly, via signals initiated by injured neurons. Activated microglia, thereby, contribute to both neuroprotection and neuroinflammation. However, sustained microglial activation initiates a chronic neuroinflammatory response which can disturb neuronal health and disrupt communications between neurons and microglia. Thus, microglia-neuron crosstalk is critical in a healthy brain as well as during states of injury or disease. As most studies focus on how neurons and microglia act in isolation during neurotrauma, there is a need to understand the interplay between these cells in brain pathophysiology. This review highlights how neurons and microglia reciprocally communicate under physiological conditions and during brain injury and disease. Furthermore, the modes of microglia-neuron communication are exposed, focusing on cell-contact dependent signaling and communication by the secretion of soluble factors like cytokines and growth factors. In addition, it has been discussed that how microglia-neuron interactions could exert either beneficial neurotrophic effects or pathologic proinflammatory responses. We further explore how aberrations in microglia-neuron crosstalk may be involved in central nervous system (CNS) anomalies, namely traumatic brain injury (TBI), neurodegeneration, and ischemic stroke. A clear understanding of how the microglia-neuron crosstalk contributes to the pathogenesis of brain pathologies may offer novel therapeutic avenues of brain trauma treatment.

A Histological and Morphometric Assessment of the Adult and Juvenile Rat Livers after Mild Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the most severe problems of modern medicine that plays a dominant role in morbidity and mortality in economically developed countries. Our experimental study aimed to evaluate the histological and morphological changes occurring in the liver of adult and juvenile mildly traumatized rats (mTBI) in a time-dependent model. The experiment was performed on 70 adult white rats at three months of age and 70 juvenile rats aged 20 days. The mTBI was modelled by the Impact-Acceleration Model-free fall of weight in the parieto-occipital area. For histopathological comparison, the samples were taken on the 1st, 3rd, 5th, 7th, 14th, and 21st days after TBI. In adult rats, dominated changes in the microcirculatory bed in the form of blood stasis in sinusoidal capillaries and veins, RBC sludge, and adherence to the vessel wall with the subsequent appearance of perivascular and focal leukocytic infiltrates. In juvenile rats, changes in the parenchyma in the form of hepatocyte dystrophy prevailed. In both groups, the highest manifestation of the changes was observed on 5–7 days of the study. On 14–21 days, compensatory phenomena prevailed in both groups. Mild TBI causes changes in the liver of both adult and juvenile rats. The morphological pattern and dynamics of liver changes, due to mild TBI, are different in adult and juvenile rats.

Decreased grey matter volume in mTBI patients with post-traumatic headache compared to headache-free mTBI patients and healthy controls: a longitudinal MRI study

Traumatic brain injury (TBI) occurs in 1.7 million people annually and many patients go on to develop persistent disorders including post-traumatic headache (PTH). PTH is considered chronic if it continues past 3 months. In this study we aimed to identify changes in cerebral grey matter volume (GMV) associated with PTH in mild TBI patients. 50 mTBI patients (31 Non-PTH; 19 PTH) underwent MRI scans: within 10 days post-injury, 1 month, 6 months and 18 months. PTH was assessed at visit 4 by a post-TBI headache questionnaire. Healthy controls (n = 21) were scanned twice 6 months apart. Compared to non-PTH, PTH patients had decreased GMV across two large clusters described as the right anterior-parietal (p = 0.012) and left temporal-opercular (p = 0.027). Compared to healthy controls non-PTH patients had decreased GMV in the left thalamus (p = 0.047); PTH patients had decreased GMV in several extensive clusters: left temporal-opercular (p = 0.003), temporal-parietal (p = 0.041), superior frontal gyrus (p = 0.008) and right middle frontal/superior frontal gyrus (0.004) and anterior-parietal (p = 0.003). Differences between PTH and non-PTH patients were most striking at early time points. These early changes may be associated with an increased risk of PTH. Patients with these changes should be monitored for chronic PTH.

The Price of Playing Through Pain: The Link Between Physical and Behavioral Health in Former NFL Athletes

Over the past decade, media outlets have drawn attention to some of the health consequences of playing in the National Football League (NFL), including how wear-and-tear and injuries accumulated during athletes’ playing years can affect their physical, emotional, and behavioral health after retirement from professional sports. Through a secondary analysis of a cross-sectional telephone survey of former NFL athletes, this study estimated logistic regression models to assess the relationship between several forms of physical pain and anger attacks, controlling for binge drinking, signs of depression, functional limitations, NFL career duration, religious service attendance, and demographic characteristics (age, marital status, race, education, income, and wealth). The analytic sample included 1030 former NFL players. Neck pain, lower back pain, headaches/migraines, and the number of sites of pain were positively and significantly related to anger attacks. There was no significant association between joint pain and anger attacks. NFL career duration was negatively associated with anger attacks, as was religious service attendance. Future research should focus on factors that protect against affective aggression in former professional athletes and how protective factors can be adapted to the broader population.

Sex-Dependent Pathology in the HPA Axis at a Sub-acute Period After Experimental Traumatic Brain Injury

Over 2.8 million traumatic brain injuries (TBIs) are reported in the United States annually, of which, over 75% are mild TBIs with diffuse axonal injury (DAI) as the primary pathology. TBI instigates a stress response that stimulates the hypothalamic-pituitary-adrenal (HPA) axis concurrently with DAI in brain regions responsible for feedback regulation. While the incidence of affective symptoms is high in both men and women, presentation is more prevalent and severe in women. Few studies have longitudinally evaluated the etiology underlying late-onset affective symptoms after mild TBI and even fewer have included females in the experimental design. In the experimental TBI model employed in this study, evidence of chronic HPA dysregulation has been reported at 2 months post-injury in male rats, with peak neuropathology in other regions of the brain at 7 days post-injury (DPI). We predicted that mechanisms leading to dysregulation of the HPA axis in male and female rats would be most evident at 7 DPI, the sub-acute time point. Young adult age-matched male and naturally cycling female Sprague Dawley rats were subjected to midline fluid percussion injury (mFPI) or sham surgery. Corticotropin releasing hormone, gliosis, and glucocorticoid receptor (GR) levels were evaluated in the hypothalamus and hippocampus, along with baseline plasma adrenocorticotropic hormone (ACTH) and adrenal gland weights. Microglial response in the paraventricular nucleus of the hypothalamus indicated mild neuroinflammation in males compared to sex-matched shams, but not females. Evidence of microglia activation in the dentate gyrus of the hippocampus was robust in both sexes compared with uninjured shams and there was evidence of a significant interaction between sex and injury regarding microglial cell count. GFAP intensity and astrocyte numbers increased as a function of injury, indicative of astrocytosis. GR protein levels were elevated 30% in the hippocampus of females in comparison to sex-matched shams. These data indicate sex-differences in sub-acute pathophysiology following DAI that precede late-onset HPA axis dysregulation. Further understanding of the etiology leading up to late-onset HPA axis dysregulation following DAI could identify targets to stabilize feedback, attenuate symptoms, and improve efficacy of rehabilitation and overall recovery.

An Exploratory Study of Endogenous Pain Modulatory Function in Patients Following Mild Traumatic Brain Injury

BACKGROUND

Recent animal research suggests that mild traumatic brain injury (mTBI) facilitates abnormal endogenous modulation of pain, potentially underlying the increased risk for persistent headaches following injury. However, no human studies have directly assessed the functioning of endogenous facilitory and inhibitory systems in the early stages after an mTBI.

OBJECTIVE

The purpose of this exploratory study was to examine trigeminal sensitization and endogenous pain inhibitory capacity in mTBI patients in the acute stage of injury compared with matched controls. We also examined whether post-traumatic headache pain intensity within the mTBI sample was related to sensitization and pain inhibitory capacity.

METHODS

Twenty-four mTBI patients recruited from emergency departments and 21 age-, race-, and sex-matched controls completed one experimental session. During this session, participants completed quantitative sensory tests measuring trigeminal sensitization (pressure pain thresholds and temporal summation of pain in the head) and endogenous pain inhibition (conditioned pain modulation). Participants also completed validated questionnaires measuring headache pain, depression, anxiety, and pain catastrophizing.

RESULTS

The results revealed that the mTBI group exhibited significantly decreased pressure pain thresholds of the head and decreased pain inhibition on the conditioned pain modulation test compared with the control group. Furthermore, correlational analysis showed that the measures of trigeminal sensitization and depression were significantly associated with headache pain intensity within the mTBI group.

CONCLUSIONS

In conclusion, mTBI patients may be at risk for maladaptive changes to the functioning of endogenous pain modulatory systems following head injury that could increase risk for post-traumatic headaches.

BDNF and IL-8, But Not UCHL-1 and IL-11, Are Markers of Brain Injury in Children Caused by Mild Head Trauma

The aim of the study was to check whether the plasma levels of brain-derived neurotrophic factor (BDNF), interleukin-8 (IL-8), interleukin-11 (IL-11) and ubiquitin C-terminal hydrolase L1 (UCHL-1) change in children with mild head trauma (N = 29) compared to controls (N = 13). Protein concentration in children with mild head trauma (12 children with mild concussion without loss of consciousness and 17 children with severe concussion and loss of consciousness) and the control group were measured by means of the Enzyme-Linked Immunosorbent Assay (ELISA) method. IL-8 and BDNF concentration was statistically higher in the group of children with mild head trauma (9.89 pg/mL and 2798.00 pg/mL, respectively) compared to the control group (7.52 pg/mL and 1163.20 pg/mL, respectively). BDNF concentration was significantly higher in children with severe concussion and loss of consciousness (3826.00 pg/mL) than in the control group. None of the tested proteins differed significantly between children with mild concussion without loss of consciousness and children with severe concussion and loss of consciousness. BDNF and IL-8 may be sensitive markers of brain response to mild head trauma in children. The lack of statistical differences for BDNF and IL-8 between children with mild or severe concussion could indicate that their elevated levels may not result from significant structural brain damage but rather reflect a functional disturbance.

Persistent Post-Traumatic Headache and Migraine: Pre-Clinical Comparisons

Background: Oftentimes, persistent post traumatic headache (PPTH) and migraine are phenotypically similar and the only clinical feature that differentiate them is the presence of a mild or moderate traumatic brain injury (mTBI). The aim of this study is to describe the differences in brain area and in biochemical cascade after concussion and to define the efficacy and safety of treatments in use. Methods: Sources were chosen in according to the International Classification of Headache Disorder (ICHD) criteria. Results: The articles demonstrated a significant difference between PPTH and migraine regarding static functional connectivity (sFC) and dynamic functional connectivity (dFC) in brain structure that could be used for exploring the pathophysiological mechanisms in PPTH. Many studies described a cascade of neuro-metabolic changes that occur after traumatic brain injury. These variations are associated to the mechanism occurring when developing a PPTH. Conclusions: The state of art of this important topic show how although the mechanisms underlying the development of the two different diseases are different, the treatment of common migraine is efficacious in patients that have developed a post traumatic form.

Elevated Serum Levels of Inflammation-Related Cytokines in Mild Traumatic Brain Injury Are Associated With Cognitive Performance

Mild traumatic brain injury (mTBI) is the most common neurological insult and leads to long-lasting cognitive impairments. The immune system modulates brain functions and plays a key role in cognitive deficits, however, the relationship between TBI-induced changes in inflammation-related cytokine levels and cognitive consequences is unclear. This was investigated in the present study in two cohorts of individuals within 1 week of mTBI (n = 52, n = 43) and 54 matched healthy control subjects. Patients with mTBI were also followed up at 1 and 3 months post-injury. Measures included cognitive assessments and a 9-plex panel of serum cytokines including interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, IL-12, chemokine ligand 2 (CCL2), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α). The contribution of cytokine levels to cognitive function was evaluated by multivariate linear regression analysis. The results showed that serum levels of IL-1β, IL-6, and CCL2 were acutely elevated in mTBI patients relative to controls; CCL2 level was remained high over 3 months whereas IL-1β and IL-6 levels were declined by 3 months post-injury. A high level of CCL2 was associated with greater severity of post-concussion symptoms (which survived in the multiple testing correction); elevated IL-1β was associated with worse working memory in acute phase (which failed in correction); and acute high CCL2 level predicted higher information processing speed at 3 months post-injury (which failed in correction). Thus, acute serum cytokine levels are useful for evaluating post-concussion symptoms and predicting cognitive outcome in participants with mTBI.

Vitamin B12 Enhances Nerve Repair and Improves Functional Recovery After Traumatic Brain Injury by Inhibiting ER Stress-Induced Neuron Injury

Traumatic brain injury (TBI) is one of the most common causes of neurological damage in young human populations. Vitamin B₁₂ has been reported to promote axon growth of neuronal cells after peripheral nerve injury, which is currently used for the treatment of peripheral nerve damage in the clinical trial. Thus, we hypothesized that TBI can be attenuated by vitaminB₁₂ treatment through its beneficial role on axon regeneration after nerve injury. To confirm it, the biological function of vitaminB₁₂ was characterized using hematoxylin and eosin (H&E) staining, Luxol fast blue (LFB) staining, western blot analysis, and immunohistochemistry staining. The results showed that the neurological functional recovery was improved in the VitaminB₁₂-treated group after TBI, which may be due to downregulation of the endoplasmic reticulum stress-related apoptosis signaling pathway. Moreover, the microtubule stabilization, remyelination and myelin reparation were rescued by vitamin B₁₂, which was consistent with the treatment of 4-phenylbutyric acid (4-PBA), an endoplasmic reticulum stress inhibitor. The study suggests that vitamin B₁₂ may be useful as a novel neuroprotective drug for TBI.

[Cognitive and paroxysmal disorders in the long-term period of traumatic brain injury in children and adolescents]

Traumatic brain injury (TBI) clinical course and outcomes in children have peculiarities as the damage impacts brain, which growth and maturation are continuing. Thus, TBI interferes into normal processes of neuroontogenesis leading to negative consequences on the cognitive functions development, school education, social skills acquisition. Cognitive and behavioral disorders in children and adolescents in the long-term period of TBI become more prominent in co-occurrence with paroxysmal disorders, including posttraumatic headaches, posttraumatic epilepsy and subclinical epileptiform activity on the EEG. Therapeutic and rehabilitation procedures in in the long-term period of TBI in children and adolescents should be conducted not only during the first 12 months after injury, when they are expected to be the most efficient, but also later on taking into consideration continuing processes of the CNS morphological and functional maturation along with the high neuroplasticity of the developing brain.

N-Acetyl Serotonin Protects Neural Progenitor Cells Against Oxidative Stress-Induced Apoptosis and Improves Neurogenesis in Adult Mouse Hippocampus Following Traumatic Brain Injury

In this study, with primary mouse neural progenitor cells (NPCs), we investigated the neuroprotective effect of a tropomyosin-related kinase receptor B (TrkB) agonist, N-acetyl serotonin (NAS), against hydrogen peroxide (H₂O₂)-induced toxicity. We found that pre-incubation with NAS not only ameliorates H₂O₂-induced cell viability loss, lactate dehydrogenase (LDH) release, and proliferative and migratory capacity impairments, but counteracts H₂O₂-triggered production of nitric oxide (NO), reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-deoxyguanosine (8-OHdG) in a dose-dependent manner. Additionally, pre-treatment with NAS was able to attenuate H₂O₂-induced apoptosis in NPCs, evidenced by the decreased percentage of apoptotic cells and altered expression of apoptosis-related factors. Furthermore, in differentiated NPCs, NAS improves H₂O₂-induced reduction in neurite growth. Mechanistic studies revealed that the protective effects of NAS in NPCs may be mediated by the TrkB/PI3K/Akt/ cAMP response element binding protein (CREB) signaling cascades. In a mouse traumatic brain injury (TBI) model, we found that systemic administration of 30 mg/kg NAS could improve hippocampal neurogenesis, manifested by the increased number of SOX-2-positive cells and increased expression of phosphorylated CREB in the dentate gyrus (DG) area. Treatment with NAS also ameliorates cognitive impairments caused by TBI, as assessed by Y-maze and contextual and cued fear conditioning tests. Taken together, these results provide valuable insights into the neuroprotective and neuroregenerative effects of NAS, suggesting it may have therapeutic potential for the treatment of TBI.

The Dynamics of Concussion: Mapping Pathophysiology, Persistence, and Recovery With Causal-Loop Diagramming

Despite increasing public awareness and a growing body of literature on the subject of concussion, or mild traumatic brain injury, an urgent need still exists for reliable diagnostic measures, clinical care guidelines, and effective treatments for the condition. Complexity and heterogeneity complicate research efforts and indicate the need for innovative approaches to synthesize current knowledge in order to improve clinical outcomes. Methods from the interdisciplinary field of systems science, including models of complex systems, have been increasingly applied to biomedical applications and show promise for generating insight for traumatic brain injury. The current study uses causal-loop diagramming to visualize relationships between factors influencing the pathophysiology and recovery trajectories of concussive injury, including persistence of symptoms and deficits. The primary output is a series of preliminary systems maps detailing feedback loops, intrinsic dynamics, exogenous drivers, and hubs across several scales, from micro-level cellular processes to social influences. Key system features, such as the role of specific restorative feedback processes and cross-scale connections, are examined and discussed in the context of recovery trajectories. This systems approach integrates research findings across disciplines and allows components to be considered in relation to larger system influences, which enables the identification of research gaps, supports classification efforts, and provides a framework for interdisciplinary collaboration and communication-all strides that would benefit diagnosis, prognosis, and treatment in the clinic.

Therapeutic Potential of Thymoquinone in Glioblastoma Treatment: Targeting Major Gliomagenesis Signaling Pathways

Glioblastoma multiforme (GBM) is one of the most devastating brain tumors with median survival of one year and presents unique challenges to therapy because of its aggressive behavior. Current treatment strategy involves surgery, radiotherapy, immunotherapy, and adjuvant chemotherapy even though optimal management requires a multidisciplinary approach and knowledge of potential complications from both the disease and its treatment. Thymoquinone (TQ), the main bioactive component of Nigella sativa L., has exhibited anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteract carcinogenesis, malignant growth, invasion, migration, and angiogenesis. TQ can specifically sensitize tumor cells towards conventional cancer treatments and minimize therapy-associated toxic effects in normal cells. Its potential to enter brain via nasal pathway due to volatile nature of TQ adds another advantage in overcoming blood-brain barrier. In this review, we summarized the potential role of TQ in different signaling pathways in GBM that have undergone treatment with standard therapeutic modalities or with TQ. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical level to delineate its implied utility as novel therapeutics to combat the challenges for the treatment of GBM.

Transfer of Minibeam Radiation Therapy into a cost-effective equipment for radiobiological studies: a proof of concept

Minibeam radiation therapy (MBRT) is an innovative synchrotron radiotherapy technique able to shift the normal tissue complication probability curves to significantly higher doses. However, its exploration was hindered due to the limited and expensive beamtime at synchrotrons. The aim of this work was to develop a cost-effective equipment to perform systematic radiobiological studies in view of MBRT. Tumor control for various tumor entities will be addressable as well as studies to unravel the distinct biological mechanisms involved in normal and tumor tissues responses when applying MBRT. With that aim, a series of modifications of a small animal irradiator were performed to make it suitable for MBRT experiments. In addition, the brains of two groups of rats were irradiated. Half of the animals received a standard irradiation, the other half, MBRT. The animals were followed-up for 6.5 months. Substantial brain damage was observed in the group receiving standard RT, in contrast to the MBRT group, where no significant lesions were observed. This work proves the feasibility of the transfer of MBRT outside synchrotron sources towards a small animal irradiator.

From blast to bench: A translational mini-review of posttraumatic headache

Current events within the military and professional sports have resulted in an increased recognition of the long-term and debilitating consequences of traumatic brain injury. Mild traumatic brain injury accounts for the majority of head injuries, and posttraumatic headache is the most common adverse effect. It is estimated that between 30% to 90% of traumatic brain injuries result in posttraumatic headache, and for a significant number of people this headache disorder can continue for up to and over a year post injury. Often, the most severe and chronic posttraumatic headache has a migraine-like phenotype and is difficult to resolve. In this review we discuss the preclinical findings from animal models of posttraumatic headache. We also describe potential mechanisms by which traumatic brain injury leads to chronic posttraumatic headache, including neuroinflammatory mediators and migraine-associated neuropeptides. There are surprisingly few preclinical studies that have investigated overlapping mechanisms between posttraumatic headache and migraine, especially considering the prevalence and debilitating nature of posttraumatic headache. Given this context, posttraumatic headache is a field with many emerging opportunities for growth. The frequency of posttraumatic headache in the general and military population is rising, and further preclinical research is required to understand, ameliorate, and treat this disabling disorder. © 2017 Wiley Periodicals, Inc.

Hepatic expression of serum amyloid A1 is induced by traumatic brain injury and modulated by telmisartan

Traumatic brain injury affects the whole body in addition to the direct impact on the brain. The systemic response to trauma is associated with the hepatic acute-phase response. To further characterize this response, we performed controlled cortical impact injury on male mice and determined the expression of serum amyloid A1 (SAA1), an apolipoprotein, induced at the early stages of the acute-phase response in liver and plasma. After cortical impact injury, induction of SAA1 was detectable in plasma at 6 hours post-injury and in liver at 1 day post-injury, followed by gradual diminution over time. In the liver, cortical impact injury increased neutrophil and macrophage infiltration, apoptosis, and expression of mRNA encoding the chemokines CXCL1 and CXCL10. An increase in angiotensin II AT1 receptor mRNA at 3 days post-injury was also observed. Administration of the AT1 receptor antagonist telmisartan 1 hour post-injury significantly decreased liver SAA1 levels and CXCL10 mRNA expression, but did not affect CXCL1 expression or the number of apoptotic cells or infiltrating leukocytes. To our knowledge, this is the first study to demonstrate that SAA1 is induced in the liver after traumatic brain injury and that telmisartan prevents this response. Elucidating the molecular pathogenesis of the liver after brain injury will assist in understanding the efficacy of therapeutic approaches to brain injury.

Mobilization and Manipulation of the Cervical Spine in Patients with Cervicogenic Headache: Any Scientific Evidence?

Cervical mobilization and manipulation are frequently used to treat patients diagnosed with cervicogenic headache (CEH); however, there is conflicting evidence on the efficacy of these manual therapy techniques. The purpose of this review is to investigate the effects of cervical mobilization and manipulation on pain intensity and headache frequency, compared to traditional physical therapy interventions in patients diagnosed with CEH. A total of 66 relevant studies were originally identified through a review of the literature, and the 25 most suitable articles were fully evaluated via a careful review of the text. Ultimately, 10 studies met the inclusion criteria: (1) randomized controlled trial (RCT) or open RCT; the study contained at least two separate groups of subjects that were randomly assigned either to a cervical spine mobilization or manipulation or a group that served as a comparison; (2) subjects must have had a diagnosis of CEH; (3) the treatment group received either spinal mobilization or spinal manipulation, while the control group received another physical therapy intervention or placebo control; and (4) the study included headache pain and frequency as outcome measurements. Seven of the 10 studies had statistically significant findings that subjects who received mobilization or manipulation interventions experienced improved outcomes or reported fewer symptoms than control subjects. These results suggest that mobilization or manipulation of the cervical spine may be beneficial for individuals who suffer from CEH, although heterogeneity of the studies makes it difficult to generalize the findings.

Trigeminal Pain Molecules, Allodynia, and Photosensitivity Are Pharmacologically and Genetically Modulated in a Model of Traumatic Brain Injury

The pain-signaling molecules, nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP), are implicated in the pathophysiology of post-traumatic headache (PTH) as they are for migraine. This study assessed the changes of inducible NOS (iNOS) and its cellular source in the trigeminal pain circuit, as well as the relationship between iNOS and CGRP after controlled cortical impact (CCI) injury in mice. The effects of a CGRP antagonist (MK8825) and sumatriptan on iNOS messenger RNA (mRNA) and protein were compared to vehicle at 2 weeks postinjury. Changes in CGRP levels in the trigeminal nucleus caudalis (TNC) in iNOS knockouts with CCI were compared to wild-type (WT) mice at 3 days and 2 weeks post injury. Trigeminal allodynia and photosensitivity were measured. MK8825 and sumatriptan increased allodynic thresholds in CCI groups compared to vehicle (p < 0.01), whereas iNOS knockouts were not different from WT. Photosensitivity was attenuated in MK8825 mice and iNOS knockouts compared to WT (p < 0.05). MK8825 and sumatriptan reduced levels of iNOS mRNA and iNOS immunoreactivity in the TNC and ganglia (p < 0.01). Differences in iNOS cellular localization were found between the trigeminal ganglia and TNC. Although the knockout of iNOS attenuated CGRP at 3 days (p < 0.05), it did not reduce CGRP at 2 weeks. CGRP immunoreactivity was found in the meningeal layers post-CCI, while negligible in controls. Findings support the importance of interactions between CGRP and iNOS in mediating allodynia, as well as the individual roles in photosensitivity. Mitigating prolonged increases in CGRP may be a promising intervention for treating acute PTH.

Deficient pain modulatory systems in patients with mild traumatic brain and chronic post-traumatic headache: implications for its mechanism

Although the prevalence rate of chronic post-traumatic headache (CPTHA) after mild traumatic brain injury (TBI) reaches up to 95%, its mechanism is unknown, and little is known about the characteristics of the pain system in this condition. Our aim was to investigate the capabilities of two pain modulatory systems among individuals with CPTHA and study their association with CPTHA, here for the first time. Forty-six subjects participated; 16 with TBI and CPTHA, 12 with TBI without CPTHA, and 18 healthy controls. Testing included the measurement of heat-pain (HPT) and pressure-pain (PPT) thresholds in the forehead and forearm, pain adaptation to tonic noxious heat, and conditioned pain modulation (CPM).The participants completed a post-traumatic stress disorder (PTSD) questionnaire. The two TBI groups did not differ in the TBI and background characteristics. However, TBI patients with CPTHA had significantly higher HPT and lower PPT in the cranium and higher PTSD symptomatology than TBI patients without CPTHA and healthy controls. Adaptation to pain and CPM were diminished in the CPTHA group compared with the two control groups. The intensity of CPTHA correlated negatively with cranial PPT, magnitude of pain adaptation, and CPM. CPTHA intensity correlated positively with PTSD symptomatology. CPTHA appears to be characterized by cranial hyperalgesia and dysfunctional pain modulation capabilities, which are associated with CPTHA magnitude. It is concluded that damage to pain modulatory systems along with chronic cranial sensitization underlies the development of CPTHA. PTSD may reinforce CPTHA and vice versa. Clinical implications are discussed.

Traumatic axonal injury and persistent emotional lability in an adolescent following moderate traumatic brain injury: A case study

A 15-year-old male was treated secondary to sustaining a moderate traumatic brain injury (moderate TBI). Symptom self-report, and computerized and paper-and-pencil-based neurocognitive, vestibular/ocular motor, and imaging data were used throughout to document impairment and recovery. The patient demonstrated persistent emotional lability concurrent with vestibular impairment. In addition to clinical evaluation and management, the patient also underwent susceptibility-weighted imaging, which revealed axonal shearing across the corpus callosum and areas innervating the prefrontal cortex. Paper-and-pencil neurocognitive measures revealed persisting deficits, despite normal-appearing computerized test results. Implications of this case underline the importance of an integrative evaluation process including clinical interview, neurocognitive and vestibular/ocular physical therapy, and advanced neuroimaging, especially in cases with atypical presentation.

New advances on glial activation in health and disease

In addition to being the support cells of the central nervous system (CNS), astrocytes are now recognized as active players in the regulation of synaptic function, neural repair, and CNS immunity. Astrocytes are among the most structurally complex cells in the brain, and activation of these cells has been shown in a wide spectrum of CNS injuries and diseases. Over the past decade, research has begun to elucidate the role of astrocyte activation and changes in astrocyte morphology in the progression of neural pathologies, which has led to glial-specific interventions for drug development. Future therapies for CNS infection, injury, and neurodegenerative disease are now aimed at targeting astrocyte responses to such insults including astrocyte activation, astrogliosis and other morphological changes, and innate and adaptive immune responses.

Long-Term Consequences of Traumatic Brain Injury: Current Status of Potential Mechanisms of Injury and Neurological Outcomes

Traumatic brain injury (TBI) is a significant clinical problem with few therapeutic interventions successfully translated to the clinic. Increased importance on the progressive, long-term consequences of TBI have been emphasized, both in the experimental and clinical literature. Thus, there is a need for a better understanding of the chronic consequences of TBI, with the ultimate goal of developing novel therapeutic interventions to treat the devastating consequences of brain injury. In models of mild, moderate, and severe TBI, histopathological and behavioral studies have emphasized the progressive nature of the initial traumatic insult and the involvement of multiple pathophysiological mechanisms, including sustained injury cascades leading to prolonged motor and cognitive deficits. Recently, the increased incidence in age-dependent neurodegenerative diseases in this patient population has also been emphasized. Pathomechanisms felt to be active in the acute and long-term consequences of TBI include excitotoxicity, apoptosis, inflammatory events, seizures, demyelination, white matter pathology, as well as decreased neurogenesis. The current article will review many of these pathophysiological mechanisms that may be important targets for limiting the chronic consequences of TBI.

In vitro cerebrovascular modeling in the 21st century: current and prospective technologies

The blood-brain barrier (BBB) maintains the brain homeostasis and dynamically responds to events associated with systemic and/or rheological impairments (e.g., inflammation, ischemia) including the exposure to harmful xenobiotics. Thus, understanding the BBB physiology is crucial for the resolution of major central nervous system CNS) disorders challenging both health care providers and the pharmaceutical industry. These challenges include drug delivery to the brain, neurological disorders, toxicological studies, and biodefense. Studies aimed at advancing our understanding of CNS diseases and promoting the development of more effective therapeutics are primarily performed in laboratory animals. However, there are major hindering factors inherent to in vivo studies such as cost, limited throughput and translational significance to humans. These factors promoted the development of alternative in vitro strategies for studying the physiology and pathophysiology of the BBB in relation to brain disorders as well as screening tools to aid in the development of novel CNS drugs. Herein, we provide a detailed review including pros and cons of current and prospective technologies for modelling the BBB in vitro including ex situ, cell based and computational (in silico) models. A special section is dedicated to microfluidic systems including micro-BBB, BBB-on-a-chip, Neurovascular Unit-on-a-Chip and Synthetic Microvasculature Blood-brain Barrier.

Insights and advances in post-traumatic headache: research considerations

Despite the growing awareness of mild traumatic brain injury in military and civilian populations, understanding of the acute and chronic effects of concussion on central nervous system structure and function is limited. Even less is understood about the underpinnings of the cardinal postconcussive symptom, post-traumatic headache (PTH). Here, we review recent advances in PTH, with special emphasis on the migraine-like phenotype, the most disabling form. Considerations for future research in PTH are discussed, including diagnostic classification, and applications with advanced neuroimaging techniques, biomarkers, and treatments.

Circadian cycle-dependent EEG biomarkers of pathogenicity in adult mice following prenatal exposure to in utero inflammation

Intrauterine infection or inflammation in preterm neonates is a known risk for adverse neurological outcomes, including cognitive, motor and behavioral disabilities. Our previous data suggest that there is acute fetal brain inflammation in a mouse model of intrauterine exposure to lipopolysaccharides (LPS). We hypothesized that the in utero inflammation induced by LPS produces long-term electroencephalogram (EEG) biomarkers of neurodegeneration in the exposed mice that could be determined by using continuous quantitative video/EEG/electromyogram (EMG) analyses. A single LPS injection at E17 was performed in pregnant CD1 dams. Control dams were injected with same volumes of saline (LPS n=10, Control n=8). At postnatal age of P90-100, 24-h synchronous video/EEG/EMG recordings were done using a tethered recording system and implanted subdural electrodes. Behavioral state scoring was performed blind to treatment group, on each 10s EEG epoch using synchronous video, EMG and EEG trace signatures to generate individual hypnograms. Automated EEG power spectrums were analyzed for delta and theta-beta power ratios during wake vs. sleep cycles. Both control and LPS hypnograms showed an ultradian wake/sleep cycling. Since rodents are nocturnal animals, control mice showed the expected diurnal variation with significantly longer time spent in wake states during the dark cycle phase. In contrast, the LPS-treated mice lost this circadian rhythm. Sleep microstructure also showed significant alteration in the LPS mice specifically during the dark cycle, caused by significantly longer average non-rapid eye movement (NREM) cycle durations. No significance was found between treatment groups for the delta power data; however, significant activity-dependent changes in theta-beta power ratios seen in controls were absent in the LPS-exposed mice. In conclusion, exposure to in utero inflammation in CD1 mice resulted in significantly altered sleep architecture as adults that were circadian cycle and activity state dependent.

Effects of ulinastatin on cerebral oxygen metabolism and CRP levels in patients with severe traumatic brain injury

The aim of the present study was to investigate the effects of ulinastatin on cerebral oxygen metabolism and C-reactive protein (CRP) levels in patients with severe traumatic brain injury (sTBI). A total of 92 patients with sTBI, admitted to the First Affiliated Hospital of Xinxiang Medical University (Xinxiang, China), were randomly divided into control and observation groups. The control group received conventional therapy plus a placebo (0.9% sodium chloride), while the observation group were administered conventional therapy plus 200,000 units ulinastatin via intravenous injection twice a day for seven days. Arterial and jugular venous blood was collected for blood gas analysis. The jugular venous blood lactate (JVBL), jugular venous bulb oxygen saturation (SjvO₂), arteriovenous oxygen content difference (AVDO₂) and cerebral extraction of oxygen (CEO₂) levels were measured on day 1, 3, 5 and 7, as well as the level of CRP in the peripheral blood. In the control group, the level of JVBL decreased as compared with the level at day 1, however, no statistically significant differences were observed (P>0.05). By contrast, the observation group exhibited a significant reduction in the level of JVBL (P<0.05), which was also significantly lower compared with the control group (P<0.05). Statistically significant differences were observed between the two groups with regard to SjvO₂, AVDO₂ and CEO₂ on day 3, 5 and 7. The CRP levels in the two groups increased and peaked on day 3. However, the CRP level in the observation group significantly decreased on day 5 (35.27±15.18 mg/l) and day 7 (22.65±10.48 mg/l), which was lower compared with the control group (56.19±13.24 mg/l and 47.36±15.73 mg/l, respectively); statistically significant differences were observed (P<0.05). Therefore, ulinastatin effectively improved cerebral oxygen metabolism and reduced the CRP level in patients with sTBI.

Clinical comparison of 99mTc exametazime and 123I Ioflupane SPECT in patients with chronic mild traumatic brain injury

Background

This study evaluated the clinical interpretations of single photon emission computed tomography (SPECT) using a cerebral blood flow and a dopamine transporter tracer in patients with chronic mild traumatic brain injury (TBI). The goal was to determine how these two different scan might be used and compared to each other in this patient population.

Methods and Findings

Twenty-five patients with persistent symptoms after a mild TBI underwent SPECT with both ^99mTc exametazime to measure cerebral blood flow (CBF) and ¹²³I ioflupane to measure dopamine transporter (DAT) binding. The scans were interpreted by two expert readers blinded to any case information and were assessed for abnormal findings in comparison to 10 controls for each type of scan. Qualitative CBF scores for each cortical and subcortical region along with DAT binding scores for the striatum were compared to each other across subjects and to controls. In addition, symptoms were compared to brain scan findings. TBI patients had an average of 6 brain regions with abnormal perfusion compared to controls who had an average of 2 abnormal regions (p<0.001). Patient with headaches had lower CBF in the right frontal lobe, and higher CBF in the left parietal lobe compared to patients without headaches. Lower CBF in the right temporal lobe correlated with poorer reported physical health. Higher DAT binding was associated with more depressive symptoms and overall poorer reported mental health. There was no clear association between CBF and DAT binding in these patients.

Conclusions

Overall, both scans detected abnormalities in brain function, but appear to reflect different types of physiological processes associated with chronic mild TBI symptoms. Both types of scans might have distinct uses in the evaluation of chronic TBI patients depending on the clinical scenario.