Dark Blood Contrast-Enhanced Brain MRI Using Echo-uT1 RESS.

BACKGROUND: The widely used magnetization-prepared rapid gradient-echo (MPRAGE) sequence makes enhancing lesions and blood vessels appear bright after gadolinium administration. However, dark blood imaging using T1-weighted Sampling Perfection with Application optimized Contrast using different flip angle Evolution (T1 SPACE) can be advantageous since it improves the conspicuity of small metastases and leptomeningeal disease. As a potential alternative to T1 SPACE, we evaluated a new dark blood sequence called echo-uT1 RESS (unbalanced T1 Relaxation-Enhanced Steady-State). PURPOSE: We compared the performance of echo-uT1 RESS with Dixon fid-uT1 RESS, MPRAGE, and T1 SPACE. STUDY TYPE: Retrospective, IRB approved. SUBJECTS/PHANTOM: Phantom to assess flow properties of echo-uT1 RESS. Twenty-one patients (14 female, age range 35-82 years) with primary and secondary brain tumors. FIELD STRENGTH/SEQUENCES: 3 Tesla/MPRAGE, T1 SPACE, Dixon fid-uT1 RESS, echo-uT1 RESS. ASSESSMENT: Flow phantom signal vs. velocity as a function of flip angle and sequence. Qualitative image assessment on 4-point scale. Quantitative evaluation of tumor-to-brain contrast, apparent contrast-to-noise ratio (aCNR), and vessel-to-brain aCNR. STATISTICAL TESTS: Friedman and Mann-Whitney U tests. A P value <0.05 was considered statistically significant. RESULTS: In the phantom, echo-uT1 RESS showed greater flow-dependent signal loss than fid-uT1 RESS. In patients, blood vessels appeared bright with MPRAGE, gray with fid-uT1 RESS, and dark with T1 SPACE and echo-uT1 RESS. For MPRAGE, Dixon fid-uT1 RESS, echo-uT1 RESS, and T1 SPACE, respective tumor-to-brain contrast values were 0.6 ± 0.3, 1.3 ± 0.5, 1.0 ± 0.4, and 0.6 ± 0.4, while normalized aCNR values were 68.9 ± 50.9, 128.4 ± 59.2, 74.2 ± 42.1, and 99.4 ± 73.9. DATA CONCLUSION: Volumetric dark blood contrast-enhanced brain MRI is feasible using echo-uT1 RESS. The dark blood effect was improved vs. fid-uT1 RESS, while both uT1 RESS versions provided better tumor-to-brain contrast than MPRAGE. Whereas T1 SPACE provided better tumor aSNR, echo-uT1 RESS provided better Weber contrast, lesion sharpness and a more consistent dark blood effect. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 1.

Examining later-in-life health risks associated with sport-related concussion and repetitive head impacts: a systematic review of case-control and cohort studies.

OBJECTIVE: Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes. DESIGN: Systematic review. DATA SOURCES: Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022. ELIGIBILITY CRITERIA: Studies measuring future risk (cohort studies) or approximating that risk (case-control studies). RESULTS: Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias. CONCLUSION: Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors. PROSPERO REGISTRATION NUMBER: CRD42022159486.

White matter alterations over the course of two consecutive high-school football seasons and the effect of a jugular compression collar: A preliminary longitudinal diffusion tensor imaging study.

The cumulative effects of repetitive subclinical head impacts during sports may result in chronic white matter (WM) changes and possibly, neurodegenerative sequelae. In this pilot study, we investigated the longitudinal WM changes over the course of two consecutive high-school football seasons and explored the long-term effects of a jugular vein compression collar on these WM alterations. Diffusion tensor imaging data were prospectively collected both pre- and postseason in the two consecutive seasons. Participants were assigned into either collar or noncollar groups. Tract-based spatial statistics (TBSS) approach and region of interest-based approach were used to quantify changes in WM diffusion properties. Despite comparable exposure to repetitive head impacts, significant reductions in mean, axial, and/or radial diffusivity were identified in Season 1 in multiple WM regions in the noncollar group but not in the collar group. After an 8- to 9-month long off-season, these changes observed in the noncollar group partially and significantly reversed but also remained significantly different from the baseline. In Season 2, trend level WM alterations in the noncollar group were found but located in spatially different regions than Season 1. Last, the WM integrity in the collar group remained unchanged throughout the four time points. In conclusion, we quantitatively assessed the WM structural changes and partial reversal over the course of two consecutive high-school football seasons. In addition, the mitigated WM alterations in athletes in the collar group might indicate potential effect of the collar in ameliorating the changes against repetitive head impacts. Hum Brain Mapp 39:491-508, 2018. © 2017 Wiley Periodicals, Inc.

Supplements, nutrition, and alternative therapies for the treatment of traumatic brain injury.

Studies using traditional treatment strategies for mild traumatic brain injury (TBI) have produced limited clinical success. Interest in treatment for mild TBI is at an all time high due to its association with the development of chronic traumatic encephalopathy and other neurodegenerative diseases, yet therapeutic options remain limited. Traditional pharmaceutical interventions have failed to transition to the clinic for the treatment of mild TBI. As such, many pre-clinical studies are now implementing non-pharmaceutical therapies for TBI. These studies have demonstrated promise, particularly those that modulate secondary injury cascades activated after injury. Because no TBI therapy has been discovered for mild injury, researchers now look to pharmaceutical supplementation in an attempt to foster success in human clinical trials. Non-traditional therapies, such as acupuncture and even music therapy are being considered to combat the neuropsychiatric symptoms of TBI. In this review, we highlight alternative approaches that have been studied in clinical and pre-clinical studies of TBI, and other related forms of neural injury. The purpose of this review is to stimulate further investigation into novel and innovative approaches that can be used to treat the mechanisms and symptoms of mild TBI.

Brainstem Monitoring in the Neurocritical Care Unit: A Rationale for Real-Time, Automated Neurophysiological Monitoring.

Patients with severe traumatic brain injury or large intracranial space-occupying lesions (spontaneous cerebral hemorrhage, infarction, or tumor) commonly present to the neurocritical care unit with an altered mental status. Many experience progressive stupor and coma from mass effects and transtentorial brain herniation compromising the ascending arousal (reticular activating) system. Yet, little progress has been made in the practicality of bedside, noninvasive, real-time, automated, neurophysiological brainstem, or cerebral hemispheric monitoring. In this critical review, we discuss the ascending arousal system, brain herniation, and shortcomings of our current management including the neurological exam, intracranial pressure monitoring, and neuroimaging. We present a rationale for the development of nurse-friendly-continuous, automated, and alarmed-evoked potential monitoring, based upon the clinical and experimental literature, advances in the prognostication of cerebral anoxia, and intraoperative neurophysiological monitoring.

Use of Head Guards in AIBA Boxing Tournaments-A Cross-Sectional Observational Study.

OBJECTIVE: This study looks at the changes in injuries after the implementation of a new rule by the International Boxing Association (AIBA) to remove head guards from its competitions. DESIGN: A cross-sectional observational study performed prospectively. This brief report examines the removal of head guards in 2 different ways. The first was to examine the stoppages due to blows to the head by comparing World Series Boxing (WSB), without head guards, to other AIBA competitions with head guards. Secondly, we examined the last 3 world championships: 2009 and 2011 (with head guards) and 2013 (without head guards). SETTING: World Series Boxing and AIBA world championship boxing. PARTICIPANTS: Boxers from WSB and AIBA world championships. INTERVENTIONS: The information was recorded by ringside medical physicians. MAIN OUTCOME MEASURES: Stoppages per 10 000 rounds; stoppages per 1000 hours. RESULTS: Both studies show that the number of stoppages due to head blows was significantly decreased without head guards. The studies also showed that there was a notable increase in cuts. CONCLUSIONS: Removing head guards may reduce the already small risk of acute brain injury in amateur boxing.

The Impact of Traumatic Brain Injury on the Aging Brain.

Traumatic brain injury (TBI) has come to the forefront of both the scientific and popular culture. Specifically, sports-related concussions or mild TBI (mTBI) has become the center of scientific scrutiny with a large amount of research focusing on the long-term sequela of this type of injury. As the populace continues to age, the impact of TBI on the aging brain will become clearer. Currently, reports have come to light that link TBI to neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, as well as certain psychiatric diseases. Whether these associations are causations, however, is yet to be determined. Other long-term sequelae, such as chronic traumatic encephalopathy (CTE), appear to be associated with repetitive injuries. Going forward, as we gain better understanding of the pathophysiological process involved in TBI and subclinical head traumas, and individual traits that influence susceptibility to neurocognitive diseases, a clearer, more comprehensive understanding of the connection between brain injury and resultant disease processes in the aging brain will become evident.

Sports-related concussions: diagnosis, complications, and current management strategies.

Sports-related concussions (SRCs) are traumatic events that affect up to 3.8 million athletes per year. The initial diagnosis and management is often instituted on the field of play by coaches, athletic trainers, and team physicians. SRCs are usually transient episodes of neurological dysfunction following a traumatic impact, with most symptoms resolving in 7-10 days; however, a small percentage of patients will suffer protracted symptoms for years after the event and may develop chronic neurodegenerative disease. Rarely, SRCs are associated with complications, such as skull fractures, epidural or subdural hematomas, and edema requiring neurosurgical evaluation. Current standards of care are based on a paradigm of rest and gradual return to play, with decisions driven by subjective and objective information gleaned from a detailed history and physical examination. Advanced imaging techniques such as functional MRI, and detailed understanding of the complex pathophysiological process underlying SRCs and how they affect the athletes acutely and long-term, may change the way physicians treat athletes who suffer a concussion. It is hoped that these advances will allow a more accurate assessment of when an athlete is truly safe to return to play, decreasing the risk of secondary impact injuries, and provide avenues for therapeutic strategies targeting the complex biochemical cascade that results from a traumatic injury to the brain.

The science and questions surrounding chronic traumatic encephalopathy.

Recently, the pathobiology, causes, associated factors, incidence and prevalence, and natural history of chronic traumatic encephalopathy (CTE) have been debated. Data from retrospective case series and high-profile media reports have fueled public fear and affected the medical community's understanding of the role of sports-related traumatic brain injury (TBI) in the development of CTE. There are a number of limitations posed by the current evidence that can lead to confusion within the public and scientific community. In this paper, the authors address common questions surrounding the science of CTE and propose future research directions.

Alzheimer's disease and chronic traumatic encephalopathy: Distinct but possibly overlapping disease entities.

BACKGROUND: Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE) have long been recognized as sharing some similar neuropathological features, mainly the presence of neurofibrilary tangles and hyperphosphorylated tau, but have generally been described as distinct entities. Evidence indicates that neurotrauma increases the risk of developing dementia and accelerates the progression of disease. Findings are emerging that CTE and AD may be present in the same patients. CLINICAL PRESENTATION: This study presents a series of previously unpublished cases, with one case demonstrating possible neurotrauma-related AD, one pure CTE, and an example of a case exhibiting features of both AD and CTE. The future significance of this work lies not only in the confirmation of AD-CTE co-existence, but, more importantly, ways of generating a hypothesis about the possibility that CTE may accelerate AD development. Understanding the relationship between neurotrauma and neurodegenerative disease will help elucidate how distinct disease entities can co-exist in the same patient. It will ultimately require the use of pre-clinical animal models and repeat injury paradigms to investigate clinically relevant injury mechanisms. These models should produce a CTE-like phenotype that must be both neuropathologically and behaviourally similar to human disease. CONCLUSION: This case series and review of the literature presents a discussion of AD and CTE in the context of neurotrauma. It highlights recent work from repetitive neurotrauma models with an emphasis on those exhibiting a CTE-like phenotype. Potential mechanisms of interest shared amongst AD and CTE are briefly addressed and future experiments are advocated for to enhance understanding of CTE pathophysiology and the relationship between CTE and AD.

Thrombolysis for intraventricular hemorrhage.

Intraventricular hemorrhage is a frequent complication of intracerebral hemorrhage and is independently associated with significant morbidity and mortality. Intraventricular fibrinolytic therapy is used with increasing frequency to accelerate clot clearance. We review the recent evidence and discuss the therapeutic benefits as well as the current concerns and limitations of fibrinolytic use in this setting.

An overview of the basic science of concussion and subconcussion: where we are and where we are going.

There has been a growing interest in the diagnosis and management of mild traumatic brain injury (TBI), or concussion. Repetitive concussion and subconcussion have been linked to a spectrum of neurological sequelae, including postconcussion syndrome, chronic traumatic encephalopathy, mild cognitive impairment, and dementia pugilistica. A more common risk than chronic traumatic encephalopathy is the season-ending or career-ending effects of concussion or its mismanagement. To effectively prevent and treat the sequelae of concussion, it will be important to understand the basic processes involved. Reviewed in this paper are the forces behind the primary phase of injury in mild TBI, as well as the immediate and delayed cellular events responsible for the secondary phase of injury leading to neuronal dysfunction and possible cell death. Advanced neuroimaging sequences have recently been developed that have the potential to increase the sensitivity of standard MRI to detect both structural and functional abnormalities associated with concussion, and have provided further insight into the potential underlying pathophysiology. Also discussed are the potential long-term effects of repetitive mild TBI, particularly chronic traumatic encephalopathy. Much of the data regarding this syndrome is limited to postmortem analyses, and at present there is no animal model of chronic traumatic encephalopathy described in the literature. As this arena of TBI research continues to evolve, it will be imperative to appropriately model concussive and even subconcussive injuries in an attempt to understand, prevent, and treat the associated chronic neurodegenerative sequelae.

Return to Play Guidelines After Cervical Spine Injuries in American Football Athletes: A Literature-Based Review.

STUDY DESIGN: Literature-based review. OBJECTIVE: We sought to evaluate clinical and case studies related to return to play (RTP) after cervical spine injuries in elite American football athletes and to formulate guidelines to help health care practitioners manage these conditions. SUMMARY OF BACKGROUND DATA: American football athletes are at unique risk of cervical spine injury and appropriate case-by-case management of cervical spine injuries is necessary for these athletes. Despite this need, no standardized guidelines exist for RTP after cervical spine injury. METHODS: Observational or case-based articles relating to RTP after cervical spine injury in American football athletes were curated from PubMed/EMBASE databases. Primary literature published before December 1, 2019 involving National Football League (NFL) or National Collegiate Athletic Association (NCAA) athletes met inclusion criteria. RESULTS: The data acquisition process yielded 28 studies addressing cervical spine injuries and RTP in American football athletes. Stingers/burners were the most common injury and placed athletes at higher risk of a more severe re-injury. Transient quadriplegia, cervical stenosis, cervical disc herniation (CDH), and cervical fractures have a more significant impact on the long-term health and career longevity of the American football athlete. As such, the literature offers some guidance for management of these athletes, including average time for RTP in patients treated nonoperatively, thresholds involving cervical stenosis, and postoperative recommendations after spinal decompression and/or fusion surgery. CONCLUSION: Elite American football athletes are at high risk for cervical spine injury due to the nature of their sport. The decision to allow these athletes to return to play should involve an understanding of the average RTP time, the potential risks of recurrence or re-injury, and individual characteristics such as position played and pathology on imaging.Level of Evidence: 3.

Sport-Related Structural Brain Injury and Return to Play: Systematic Review and Expert Insight.

BACKGROUND: Sport-related structural brain injury (SRSBI) is intracranial pathology incurred during sport. Management mirrors that of non-sport-related brain injury. An empirical vacuum exists regarding return to play (RTP) following SRSBI. OBJECTIVE: To provide key insight for operative management and RTP following SRSBI using a (1) focused systematic review and (2) survey of expert opinions. METHODS: A systematic literature review of SRSBI from 2012 to present in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and a cross-sectional survey of RTP in SRSBI by 31 international neurosurgeons was conducted. RESULTS: Of 27 included articles out of 241 systematically reviewed, 9 (33.0%) case reports provided RTP information for 12 athletes. To assess expert opinion, 31 of 32 neurosurgeons (96.9%) provided survey responses. For acute, asymptomatic SRSBI, 12 (38.7%) would not operate. Of the 19 (61.3%) who would operate, midline shift (63.2%) and hemorrhage size > 10 mm (52.6%) were the most common indications. Following SRSBI with resolved hemorrhage, with or without burr holes, the majority of experts (>75%) allowed RTP to high-contact/collision sports at 6 to 12 mo. Approximately 80% of experts did not endorse RTP to high-contact/collision sports for athletes with persistent hemorrhage. Following craniotomy for SRSBI, 40% to 50% of experts considered RTP at 6 to 12 mo. Linear regression revealed that experts allowed earlier RTP at higher levels of play (ß = -0.58, 95% CI -0.111, -0.005, P = .033). CONCLUSION: RTP decisions following structural brain injury in athletes are markedly heterogeneous. While individualized RTP decisions are critical, aggregated expert opinions from 31 international sports neurosurgeons provide key insight. Level of play was found to be an important consideration in RTP determinations.

Diffusion Tensor Imaging Detects Acute and Subacute Changes in Corpus Callosum in Blast-Induced Traumatic Brain Injury.

There is a critical need for understanding the progression of neuropathology in blast-induced traumatic brain injury using valid animal models to develop diagnostic approaches. In the present study, we used diffusion imaging and magnetic resonance (MR) morphometry to characterize axonal injury in white matter structures of the rat brain following a blast applied via blast tube to one side of the brain. Diffusion tensor imaging was performed on acute and subacute phases of pathology from which fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated for corpus callosum (CC), cingulum bundle, and fimbria. Ventricular volume and CC thickness were measured. Blast-injured rats showed temporally varying bilateral changes in diffusion metrics indicating persistent axonal pathology. Diffusion changes in the CC suggested vasogenic edema secondary to axonal injury in the acute phase. Axonal pathology persisted in the subacute phase marked by cytotoxic edema and demyelination which was confirmed by ultrastructural analysis. The evolution of pathology followed a different pattern in the cingulum bundle: axonal injury and demyelination in the acute phase followed by cytotoxic edema in the subacute phase. Spatially, structures close to midline were most affected. Changes in the genu were greater than in the body and splenium; the caudal cingulum bundle was more affected than the rostral cingulum. Thinning of CC and ventriculomegaly were greater only in the acute phase. Our results reveal the persistent nature of blast-induced axonal pathology and suggest that diffusion imaging may have potential for detecting the temporal evolution of blast injury.

Navigable Channel-Based Trans-Sulcal Resection of Third Ventricular Colloid Cysts: A Multicenter Retrospective Case Series and Review of the Literature.

BACKGROUND: Developments in frameless neuronavigation and tubular retractors hold the potential for minimizing iatrogenic injury to the overlying cortex and subcortical tracts, with improved access to the ventricular system. The objective of the present study was to evaluate the surgical outcomes after resection of third ventricular colloid cysts using an integrated neuronavigation and channel-based approach. METHODS: We performed a multicenter retrospective analysis of surgical Outcomes after surgical resection of third ventricular colloid cysts via a transtubular trans-sulcal approach. RESULTS: A total of 16 patients were included, with a mean age of 42 years (range, 23-62 years). The mean maximum diameter of cysts was 14 mm (range, 7-28 mm), and preoperative hydrocephalous was present in 12 patients (75%). Gross total resection was achieved in all 16 cases. Of the 12 patients, 4 (25%) had undergone septum pellucidotomy, in addition to cyst resection. No case had required conversion to open craniotomy. No perioperative mortalities occurred. Three patients (18.8%) had developed transient memory deficits, 1 of whom had also developed a pulmonary thromboembolism. The median length of hospital stay was 4 days (range, 2-18 days). All the patients reported resolution of preoperative symptoms at the 1-month follow-up examination. Only 1 patient (6.25%) had required insertion of a ventriculoperitoneal shunt. The median follow-up duration was 6.5 months (range, 3-24 months), and no recurrences were observed. CONCLUSION: Use of a channel-based navigable retractor provided a minimal trans-sulcal approach to third ventricular colloid cysts with the benefit of bimanual surgical control in an air medium for definitive resection of third ventricular colloid cysts.