The Impact of Age and Severity on Dementia After Traumatic Brain Injury: A Comparison Study

BACKGROUND

Growing evidence associates traumatic brain injury (TBI) with increased risk of dementia, but few studies have evaluated associations in patients younger than 55 yr using non-TBI orthopedic trauma (NTOT) patients as controls to investigate the influence of age and TBI severity, and to identify predictors of dementia after trauma.

OBJECTIVE

To investigate the relationship between TBI and dementia in an institutional group.

METHODS

Retrospective cohort study (2000-2018) of TBI patients aged 45 to 100 yr vs NTOT controls. Primary outcome was dementia after TBI (followed ≤10 yr). Cox proportional hazards models were used to assess risk of dementia; logistic regression models assessed predictors of dementia.

RESULTS

Among 24 846 patients, TBI patients developed dementia (7.5% vs 4.6%) at a younger age (78.6 vs 82.7 yr) and demonstrated higher 10-yr mortality than controls (27% vs 14%; P < .001). Mild TBI patients had higher incidence of dementia (9%) than moderate/severe TBI (5.4%), with lower 10-yr mortality (20% vs 31%; P < .001). Risk of dementia was significant in all mild TBI age groups, even 45 to 54 yr (hazard ratio 4.1, 95% CI 2.7-7.8). A total of 10-yr cumulative incidence was higher in mild TBI (14.4%) than moderate/severe TBI (11.3%) and controls (6.8%) (P < .001). Predictors of dementia include TBI, sex, age, hypertension, hyperlipidemia, stroke, depression, anxiety, and Injury Severity Score.

CONCLUSION

Mild and moderate/severe TBI patients experienced higher incidence of dementia, even in the youngest group (45-54 yr old), than NTOT controls. All TBI patients, especially middle-aged adults with minor injury who are more likely to be overlooked, should be monitored for dementia.

Location of Subcortical Microbleeds and Recovery of Consciousness After Severe Traumatic Brain Injury

BACKGROUND

In patients with severe traumatic brain injury (TBI), coma is associated with impaired subcortical arousal mechanisms. However, it is unknown which nuclei involved in arousal (arousal nuclei) are implicated in coma pathogenesis and are compatible with coma recovery.

METHODS

We mapped an atlas of arousal nuclei in the brainstem, thalamus, hypothalamus, and basal forebrain onto 3 tesla susceptibility-weighted images (SWI) in 12 patients with acute severe TBI who presented in coma and recovered consciousness within 6 months. We assessed the spatial distribution and volume of SWI microbleeds and evaluated the association of microbleed volume with the duration of unresponsiveness and functional recovery at 6 months.

RESULTS

There was no single arousal nucleus affected by microbleeds in all patients. Rather, multiple combinations of microbleeds in brainstem, thalamic, and hypothalamic arousal nuclei were associated with coma and were compatible with recovery of consciousness. Microbleeds were frequently detected in the midbrain (100%), thalamus (83%), and pons (75%). Within the brainstem, the microbleed incidence was largest within the mesopontine tegmentum (e.g., pedunculotegmental nucleus, mesencephalic reticular formation) and ventral midbrain (e.g., substantia nigra, ventral tegmental area). Brainstem arousal nuclei were partially affected by microbleeds, with microbleed volume not exceeding 35% of brainstem nucleus volume on average. Compared to microbleed volume within nonarousal brainstem regions, the microbleed volume within arousal brainstem nuclei accounted for a larger proportion of variance in the duration of unresponsiveness and 6-month Glasgow Outcome Scale-Extended scores.

CONCLUSION

These results suggest resilience of arousal mechanisms in the human brain after severe TBI.

Treatment of Subarachnoid Hemorrhage-associated Delayed Cerebral Ischemia With Milrinone: A Review and Proposal

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage continues to be associated with high levels of morbidity and mortality. This complication had long been thought to occur secondary to severe cerebral vasospasm, but expert opinion now favors a multifactorial etiology, opening the possibility of new therapies. To date, no definitive treatment option for DCI has been recommended as standard of care, highlighting a need for further research into potential therapies. Milrinone has been identified as a promising therapeutic agent for DCI, possessing a mechanism of action for the reversal of cerebral vasospasm as well as potentially anti-inflammatory effects to treat the underlying etiology of DCI. Intra-arterial and intravenous administration of milrinone has been evaluated for the treatment of DCI in single-center case series and cohorts and appears safe and associated with improved clinical outcomes. Recent results have also brought attention to the potential outcome benefits of early, more aggressive dosing and titration of milrinone. Limitations exist within the available data, however, and questions remain about the generalizability of results across a broader spectrum of patients suffering from DCI. The development of a standardized protocol for milrinone use in DCI, specifically addressing areas requiring further clarification, is needed. Data generated from a standardized protocol may provide the impetus for a multicenter, randomized control trial. We review the current literature on milrinone for the treatment of DCI and propose a preliminary standardized protocol for further evaluation of both safety and efficacy of milrinone.

Cell-specific activation of RIPK1 and MLKL after intracerebral hemorrhage in mice

Receptor-interacting protein kinase-1 (RIPK1) is a master regulator of cell death and inflammation, and mediates programmed necrosis (necroptosis) via mixed-lineage kinase like (MLKL) protein. Prior studies in experimental intracerebral hemorrhage (ICH) implicated RIPK1 in the pathogenesis of neuronal death and cognitive outcome, but the relevant cell types involved and potential role of necroptosis remain unexplored. In mice subjected to autologous blood ICH, early RIPK1 activation was observed in neurons, endothelium and pericytes, but not in astrocytes. MLKL activation was detected in astrocytes and neurons but not endothelium or pericytes. Compared with WT controls, RIPK1 kinase-dead (RIPK1^D138N/D138N) mice had reduced brain edema (24 h) and blood-brain barrier (BBB) permeability (24 h, 30 d), and improved postinjury rotarod performance. Mice deficient in MLKL (Mlkl^-/-) had reduced neuronal death (24 h) and BBB permeability at 24 h but not 30d, and improved post-injury rotarod performance vs. WT. The data support a central role for RIPK1 in the pathogenesis of ICH, including cell death, edema, BBB permeability, and motor deficits. These effects may be mediated in part through the activation of MLKL-dependent necroptosis in neurons. The data support development of RIPK1 kinase inhibitors as therapeutic agents for human ICH.

Concussion and Risk of Chronic Medical and Behavioral Health Comorbidities

While chronic neurological effects from concussion have been studied widely, little is known about possible links between concussion and long-term medical and behavioral comorbidities. We performed a retrospective cohort study of 9205 adult patients with concussion, matched to non-concussion controls from a hospital-based electronic medical registry. Patients with comorbidities before the index visit were excluded. Behavioral and medical comorbidities were defined by International Classification of Diseases, Ninth and Tenth Revision codes. Groups were followed for up to 10 years to identify comorbidity incidence after a concussion. Cox proportional hazards models were used to calculate associations between concussion and comorbidities after multi-variable adjustment. Patients with concussion were 57% male (median age: 31; interquartile range [IQR] = 23-48 years) at enrollment with a median follow-up time of 6.1 years (IQR = 4.2-9.1) and well-matched to healthy controls. Most (83%) concussions were evaluated in outpatient settings (5% inpatient). During follow-up, we found significantly higher risks of cardiovascular risks developing including hypertension (hazard ratio [HR] = 1.7, 95% confidence interval [CI]: 1.5-1.9), obesity (HR = 1.7, 95% CI: 1.3-2.0), and diabetes mellitus (HR = 1.8, 95% CI: 1.4-2.3) in the concussion group compared with controls. Similarly, psychiatric and neurological disorders such as depression (HR = 3.0, 95% CI: 2.6-3.5), psychosis (HR = 6.0, 95% CI: 4.2-8.6), stroke (HR = 2.1 95% CI: 1.5-2.9), and epilepsy (HR = 4.4, 95% CI: 3.2-5.9) were higher in the concussion group. Most comorbidities developed less than five years post-concussion. The risks for post-concussion comorbidities were also higher in patients under 40 years old compared with controls. Patients with concussion demonstrated an increased risk of development of medical and behavioral health comorbidities. Prospective studies are warranted to better describe the burden of long-term comorbidities in patients with concussion.

Comorbidities and Age Are Associated With Persistent COVID-19 PCR Positivity

Objectives

The impact of demographics and comorbidities on the duration of COVID-19 nasopharyngeal swab PCR positivity remains unclear. The objective of our analysis is to determine the impact of age, intensive care unit (ICU) admission, comorbidities, and ethnicity on the duration of COVID-19 PCR positivity among hospitalized patients in a large group of hospital.

Method

We studied 530 patients from a large hospital system and time to SARS-CoV-2 virus RNA PCR negativity at any-time during hospitalization or following discharge from the hospital was the primary endpoint. We included patients 18 years or older who tested positive for COVID-19 during an inpatient, outpatient, or emergency room visit between February 1, 2020, and April 14, 2020.

Results

Overall, 315 (59.4%) of our patient population continued to have a positive SARS-CoV-2 virus RNA PCR 4 weeks after the initial positive test. We found that age>70 years, chronic kidney disease, hypertension, hyperlipidemia, obesity, or coronary artery disease are associated with persistent PCR positivity for more than 4 weeks after initial diagnosis.

Conclusion

Age, and the presence of co-morbidities should be taken into consideration when interpreting a positive COVID PCR test.

Extra-Axial Fluid Collections After Decompressive Craniectomy: Management, Outcomes, and Treatment Algorithm

BACKGROUND

Extra-axial fluid collections (EACs) frequently develop after decompressive craniectomy. Management of EACs remains poorly understood, and information on how to predict their clinical course is inadequate. We aimed to better characterize EACs, understand predictors of their resolution, and delineate the best treatment paradigm for patients.

METHODS

We reviewed patients who developed EACs after undergoing decompressive craniectomy for treatment of refractory intracranial pressure elevations. We excluded patients who had an ischemic stroke, as EACs in these patients have a different clinical course. We performed univariate analysis and multiple linear regression to find variables associated with earlier resolution of EACs and stratified our analyses by EAC phenotype (complicated vs. uncomplicated). We conducted a systematic review to compare our findings with the literature.

RESULTS

Of 96 included patients, 73% were male, and median age was 42.5 years. EACs resolved after a median of 60 days. Complicated EACs were common (62.5%) and required multiple drainage methods before cranioplasty. These were not associated with a protracted course or increased risk of death (P > 0.05). Early bone flap restoration with simultaneous drainage was independently associated with earlier resolution of EACs (β = 0.56, P < 0.001). Systematic review confirmed lack of standardized direction with respect to EAC management.

CONCLUSIONS

Our analyses reveal 2 clinically relevant phenotypes of EAC: complicated and uncomplicated. Our proposed treatment algorithm involves replacing the bone flap as soon as it is safe to do so and draining refractory EACs aggressively. Further studies to assess long-term clinical outcomes of EACs are warranted.

Endovascular treatment of a ruptured posterior fossa pure arterial malformation: illustrative case

BACKGROUND

Pure arterial malformations (PAMs) are rare vascular anomalies that are commonly mistaken for other vascular malformations. Because of their purported benign natural history, PAMs are often conservatively managed. The authors report the case of a ruptured PAM leading to subarachnoid hemorrhage (SAH) with intraventricular extension that was treated endovascularly.

OBSERVATIONS

A 38-year-old man presented with a 1-day history of headaches and nausea. A computed tomography scan demonstrated diffuse SAH with intraventricular extension, and angiography revealed a right posterior inferior cerebellar artery-associated PAM. The PAM was treated with endovascular Onyx embolization.

LESSONS

To the authors' knowledge, only 2 other cases of SAH associated with PAM have been reported. In those 2 cases, surgical clipping was pursued for definitive treatment. Here, the authors report the first case of a ruptured PAM treated using an endovascular approach, showing its feasibility as a treatment option particularly in patients in whom open surgery is too high a risk.

Diffuse Cerebral Edema After Moyamoya Disease-Related Intracerebral Hemorrhage: A Case Report

Moyamoya disease (MMD) is a rare, progressive occlusive disease characterized by bilateral internal carotid artery hypoplasia that often presents with ischemic stroke and intracerebral hemorrhage (ICH). Although MMD-related ICH is generally managed similarly to spontaneous ICH, we present a case in which standard management strategies may have led to an unprecedented devastating outcome. A 37-year-old female without any previous medical history presented with headache and right-sided weakness. A computed tomography (CT) scan revealed a large left basal ganglia ICH. Vessel imaging revealed diffuse narrowing of the entire anterior circulation with prominent leptomeningeal collaterals consistent with MMD. The patient's systolic blood pressure was kept under 140 mmHg. During the hospitalization, she became hypocarbic while being trialed on pressure support ventilation. Several hours later, she developed fixed and dilated pupils. Repeat CT head showed new diffuse cerebral edema with tonsillar herniation. Despite hyperosmolar therapy, paralytics, pentobarbital, and cerebrospinal fluid diversion, no improvement was noted. Unfortunately, brain MRI revealed multifocal brainstem infarcts with superimposed Duret hemorrhages. Herein, we report diffuse cerebral edema as a complication of MMD-related ICH. We hypothesize that disruptions of delicate cerebral autoregulatory mechanisms led to extensive hypoxic-ischemic injury. In the setting of ICH, aggressive blood pressure management coupled with relative hypocapnia may have likely caused vasoconstriction of poorly compliant arteries leading to worsened cerebral blood flow and ischemia. Therefore, because of its complex pathophysiology, strict adherence to eucapnia should be maintained in MMD-related ICH.

Spontaneous hemorrhage after external ventricular drain placement in the setting of low factor VII secondary to liver cirrhosis

Background:

Alterations in normal coagulation and hemostasis are critical issues that require special attention in the neurosurgical patient. These disorders pose unique challenges in the management of these patients who often have concurrent acute ischemic and hemorrhagic injuries. Although neurosurgical intervention in such cases may be unavoidable and potentially life-saving, these patients should be closely observed after instrumentation.

Case Description:

A 57-year-old male with liver cirrhosis secondary to amyloid light-chain amyloidosis was admitted to the intensive care unit for the management of delayed hydrocephalus. An external ventricular drain (EVD) was placed for the treatment and monitoring of hydrocephalus. Five days after EVD placement, a head computed tomography scan revealed a tract hemorrhage. However, on repeated imaging, the size of the hemorrhage continued to increase despite aggressive blood pressure control and several doses of phytonadione. Extensive coagulopathy workup was remarkable for low factor VII levels. In that setting, recombinant activated factor VII was administered to normalize factor VII levels, and the tract hemorrhage stabilized.

Conclusion:

To the best of our knowledge, this is the first case of spontaneous hemorrhage after EVD placement in the setting of liver cirrhosis-associated factor VII deficiency. Our case highlights the importance of identifying coagulation disorders in neurosurgical patients at high risk for coagulopathy and closely monitoring them postoperatively.

Divergence in the epidemiological estimates of traumatic brain injury in the United States: comparison of two national databases

OBJECTIVE

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in the US, but the true incidence of TBI is unknown.

METHODS

The National Trauma Data Bank National Sample Program (NTDB NSP) was queried for 2007 and 2013, and population-based weighted estimates of TBI-related emergency department (ED) visits, hospitalizations, and deaths were calculated. These data were compared to the 2017 Centers for Disease Control and Prevention (CDC) report on TBI, which used the Healthcare Cost and Utilization Project's National ("Nationwide" before 2012) Inpatient Sample and National Emergency Department Sample.

RESULTS

In the NTDB NSP the incidence of TBI-related ED visits was 59/100,000 in 2007 and 62/100,000 in 2013. However, in the CDC report there were 534/100,000 in 2007 and 787/100,000 in 2013. The CDC estimate for ED visits was 805% higher in 2007 and 1169% higher in 2013. In the NTDB NSP, the incidence of TBI-related deaths was 5/100,000 in 2007 and 4/100,000 in 2013. In the CDC report, the incidence was 18/100,000 in both years. The CDC estimate for deaths was 260% higher in 2007 and 325% higher in 2013.

CONCLUSIONS

The databases disagreed widely in their weighted estimates of TBI incidence: CDC estimates were consistently higher than NTDB NSP estimates, by an average of 448%. Although such a discrepancy may be intuitive, this is the first study to quantify the magnitude of disagreement between these databases. Given that research, funding, and policy decisions are made based on these estimates, there is a need for a more accurate estimate of the true national incidence of TBI.

Characteristics and Outcomes of Latinx Patients With COVID-19 in Comparison With Other Ethnic and Racial Groups

BACKGROUND

There is a limited understanding of the impact of coronavirus disease 2019 (COVID-19) on the Latinx population. We hypothesized that Latinx patients would be more likely to be hospitalized and admitted to the intensive care unit (ICU) than White patients.

METHODS

We analyzed all patients with COVID-19 in 12 Massachusetts hospitals between February 1 and April 14, 2020. We examined the association between race, ethnicity, age, reported comorbidities, and hospitalization and ICU admission using multivariable regression.

RESULTS

Of 5190 COVID-19 patients, 29% were hospitalized; 33% required the ICU, and 4.3% died. Forty-six percent of patients were White, 25% Latinx, 14% African American, and 3% Asian American. Ethnicity and race were significantly associated with hospitalization. More Latinx and African American patients in the younger age groups were hospitalized than whites. Latinxs and African Americans disproportionally required the ICU, with 39% of hospitalized Latinx patients requiring the ICU compared with 33% of African Americans, 24% of Asian Americans, and 30% of Whites (P < .007). Within each ethnic and racial group, age and male gender were independently predictive of hospitalization. Previously reported preexisting comorbidities contributed to the need for hospitalization in all racial and ethnic groups (P < .05). However, the observed disparities were less likely related to reported comorbidities, with Latinx and African American patients being admitted at twice the rate of Whites, regardless of such comorbidities.

CONCLUSIONS

Latinx and African American patients with COVID-19 have higher rates of hospitalization and ICU admission than White patients. The etiologies of such disparities are likely multifactorial and cannot be explained only by reported comorbidities.

Trends in incidence and epidemiologic characteristics of cerebral venous thrombosis in the United States

OBJECTIVE

To test the hypothesis that race-, age-, and sex-specific incidence of cerebral venous thrombosis (CVT) has increased in the United States over the last decade.

METHODS

In this retrospective cohort study, validated ICD codes were used to identify all new cases of CVT (n = 5,567) in the State Inpatients Databases (SIDs) of New York and Florida (2006-2016). A new CVT case was defined as first hospitalization for CVT in the SID without prior CVT hospitalization. CVT counts were combined with annual Census data to compute incidence. Joinpoint regression was used to evaluate trends in incidence over time.

RESULTS

From 2006 to 2016, annual age- and sex-standardized incidence of CVT in cases per 1 million population ranged from 13.9 to 20.2, but incidence varied significantly by sex (women 20.3-26.9, men 6.8-16.8) and by age/sex (women 18-44 years of age 24.0-32.6, men 18-44 years of age 5.3-12.8). Incidence also differed by race (Blacks: 18.6-27.2; Whites: 14.3-18.5; Asians: 5.1-13.8). On joinpoint regression, incidence increased across 2006 to 2016, but most of this increase was driven by an increase in all age groups of men (combined annualized percentage change [APC] 9.2%, p < 0.001), women 45 to 64 years of age (APC 7.8%, p < 0.001), and women ≥65 years of age (APC 7.4%, p < 0.001). Incidence in women 18 to 44 years of age remained unchanged over time.

CONCLUSION

CVT incidence is disproportionately higher in Blacks compared to other races. New CVT hospitalizations increased significantly over the last decade mainly in men and older women. Further studies are needed to determine whether this increase represents a true increase from changing risk factors or an artifactual increase from improved detection.

COVID-19 in solid organ transplant recipients: Dynamics of disease progression and inflammatory markers in ICU and non-ICU admitted patients

BACKGROUND

COVID-19 infection varies in severity from minimal symptoms to critical illness associated with a hyperinflammatory response. Data on disease progression in immunosuppressed solid organ transplant (SOT) recipients are limited.

METHODS

We examined the electronic medical records of all SOT recipients with COVID-19 from 12 Massachusetts hospitals between February 1, and May 6, 2020. We analyzed the demographics, clinical parameters, course, and outcomes of illness in these patients.

RESULTS

Of 52 COVID-19-positive SOT patients, 77% were hospitalized and 35% required ICU admission. Sixty-nine percent of hospitalized patients had immunosuppression reduced, 6% developed suspected rejection. Co-infections occurred in 45% in ICU vs 5% in non-ICU patients (P = .037). A biphasic pattern of evolution of laboratory tests was observed. In the first 5 days of illness, inflammatory markers were moderately increased. Subsequently, WBC, CRP, ferritin, and D Dimer increased with increasing stay in the ICU, and lymphocyte counts were similar. Five patients (16%) died.

CONCLUSIONS

Our data indicate that SOT is associated with high rate of hospitalization, ICU admission, and death from COVID-19 compared to data in the general population of patients with COVID-19. Despite reduction in immunosuppression, suspected rejection was rare. The clinical course and trend of laboratory biomarkers is biphasic with a later, pronounced peak in inflammatory markers seen in those admitted to an ICU. CRP is a useful marker to monitor disease progression in SOT.

Abstract WMP60: Temporal Trends in Incidence, Prevalence and Epidemiological Characteristics of Cerebral Venous Thrombosis in the United States

Background: The primary aim of this study is to describe current trends in racial-, age- and sex-specific incidence, clinical characteristics and burden of cerebral venous thrombosis (CVT) in the United States (US).

Methods: Validated International Classification of Disease codes were used to identify all adult new cases of CVT (n=5,567) in the State Inpatients Database of New York and Florida (2006-2016) and all cases of CVT in the entire US from the National Inpatient Sample 2005-2016 (weighted n=57,315). Incident CVT counts were combined with annual US Census data to compute age and sex-specific incidence of CVT. Joinpoint regression was used to evaluate trends in incidence over time.

Results: From 2005-2016, 0.47%-0.80% of all strokes in the US were CVTs but this proportion increased by 70.4% over time. Of all CVTs over this period, 66.7% were in females but this proportion declined over time (p<0.001). Pregnancy/puerperium (27.4%) and cancer (11.8%) were the most common risk factors in women, while cancer (19.5%) and central nervous trauma (11.3) were the most common in men. Whereas the prevalence of pregnancy/puerperium declined significantly over time in women, that of cancer, inflammatory conditions and trauma increased over time in both sexes. Annual age and sex-standardized incidence of CVT in cases/million population ranged from 13.9-20.2, but incidence varied significantly by sex (women: 20.3-26.9; men 6.8-16.8) and by age/sex (women 18-44yo: 24.0-32.6%; men: 18-44yo: 5.3-12.8). Age and sex-standardized incidence also differed by race (Blacks:18.6-27.2; whites: 14.3-18.5; Asians: 5.1-13.8). On joinpoint regression, incidence increased across 2006-2016 but most of this increase was driven by increase in all age groups of men (combined annualized percentage change (APC) 9.2%, p-value <0.001), women 45-64 yo (APC 7.8%, p-value <0.001) and women ≥65 yo (APC 7.4%, p-value <0.001). Incidence in women 18-44 yo remained unchanged over time .

Conclusion: The epidemiological characteristics of CVT patients in the US is changing. Incidence increased significantly over the last decade. Further studies are needed to determine whether this increase represents a true increase from changing risk factors or artefactual increase from improved detection.

Repetitive head injury in adolescent mice: A role for vascular inflammation

Repetitive mild traumatic brain injury during adolescence can induce neurological dysfunction through undefined mechanisms. Interleukin-1 (IL-1) contributes to experimental adult diffuse and contusion TBI models, and IL-1 antagonists have entered clinical trials for severe TBI in adults; however, no such data exist for adolescent TBI. We developed an adolescent mouse repetitive closed head injury (rCHI) model to test the role of IL-1 family members in post-injury neurological outcome. Compared to one CHI, three daily injuries (3HD) produced acute and chronic learning deficits and emergence of hyperactivity, without detectable gliosis, neurodegeneration, brain atrophy, and white matter loss at one year. Mature IL-1β and IL-18 were induced in brain endothelium in 3HD but not 1HD, three hit weekly, or sham animals. IL-1β processing was induced cell-autonomously in three-dimensional human endothelial cell cultures subjected to in vitro concussive trauma. Mice deficient in IL-1 receptor-1 or caspase-1 had improved post-injury Morris water maze performance. Repetitive mild CHI in adolescent mice may induce behavioral deficits in the absence of significant histopathology. The endothelium is a potential source of IL-1β and IL-18 in rCHI, and IL-1 family members may be therapeutic targets to reduce or prevent neurological dysfunction after repetitive mild TBI in adolescents.

Traumatic brain injury as a risk factor for dementia

Introduction

The Centers for Disease Control and Prevention (CDC) reports that there were 2.87 million cases of traumatic brain injury (TBI) in the United States in 2014, 69 million worldwide. Some studies suggest a connection between TBI and increased risk of dementia, but it remains unclear whether the risk increases with age and TBI severity. Given our aging population, it is essential to better characterize the link between TBI and dementia.

Methods

We conducted a retrospective cohort study of two major academic medical centers for years 2000-2015. We identified all patients with TBI, aged 45 and older. Variables included age, TBI severity, pre-existing dementia, dementia diagnosed after TBI, years to dementia, and follow-up time. TBI severity was determined by head/neck AIS score, using ICD-PIC software. Mild TBI was defined as AIS 0-2, and Moderate/Severe as AIS 3-6. Analysis was done in R.v.3.0.1 software.

Results

Overall, there were 14,199 patients with TBI, of which 9,938 (70%) were mild and 4,261 (30%) were moderate/severe. Mean age was 70.5 (±14.0). There were 1,422 cases (10%) of pre-existing dementia, and 850 (6%) cases of dementia diagnosed after TBI. The mean follow-up time was 1,129 (±1,474) days.

The 75-84 age group had the highest incidence of TBI (28%). When compared by age group and TBI severity, the proportion of moderate/severe TBI increased with increasing age. The proportion of pre-existing dementia increased with age, as expected. Notably, there is increased incidence of dementia after TBI in patients aged 65 and older (7-10%, p &lt; 0.001). There was no observed effect of TBI severity on the risk of dementia after TBI.

Conclusions

Our results indicate that TBI is a risk factor for the development of dementia, especially in patients aged 65 and older. Given the global public health burden of these two diseases it is critical to develop effective TBI primary prevention strategies.

Key messages

TBI is a risk factor for the development of dementia. Need for public health measures to mitigate the risk of TBI in the patient population 65 and older.

Traumatic Brain Injury as a Risk Factor for Dementia: An Eighteen-Year Two Institution Clinical Experience

INTRODUCTION

The Centers for Disease Control and Prevention (CDC) reports that there were 2.87 million cases of traumatic brain injury (TBI) in the United States in 2014. Some studies suggest a connection between TBI and increased risk of dementia, but it remains unclear whether the risk increases with age and TBI severity. Given our aging population, it is essential to better characterize the link between TBI and dementia.

METHODS

We conducted a retrospective cohort study of 2 major academic medical centers for years 2000 to 2015. We identified all patients with TBI, aged 45 and older. Variables included age, TBI severity, pre-existing dementia, dementia diagnosed after TBI, years to dementia, and follow-up time. TBI severity was determined by head/neck AIS score, using ICD-PIC software. Mild TBI was defined as AIS 0 to 2, and moderate/severe as AIS 3 to 6. Analysis was done in R.v.3.0.1 software.

RESULTS

Overall, there were 14 199 patients with TBI, of which 9938 (70%) were mild and 4261 (30%) were moderate/severe. Mean age was 70.5 (± 14.0). There were 1422 cases (10%) of pre-existing dementia, and 850 (6%) cases of dementia diagnosed after TBI. The mean follow-up time was 1129 (± 1,474) d. The 75 to 84 age group had the highest incidence of TBI (28%). When compared by age group and TBI severity, the proportion of moderate/severe TBI increased with increasing age. The proportion of pre-existing dementia increased with age, as expected. Notably, there is increased incidence of dementia after TBI in patients aged 65 and older (7%-10%, P < .001). There was no observed effect of TBI severity on the risk of dementia after TBI.

CONCLUSION

Our results indicate that TBI is a risk factor for the development of dementia, especially in patients aged 65 and older. This points to the need for public health measures to mitigate the risk of TBI in this patient population.

Education Research: Variation in priorities for neurocritical care education expressed across role groups

OBJECTIVE

To define expectations for neurocritical care (NCC) core competencies vs competencies considered within the domain of other subspecialists.

METHODS

An electronic survey was disseminated nationally to NCC nurses, physicians, fellows, and neurology residents through Accreditation Council for Graduate Medical Education neurology residency program directors, United Council for Neurologic Subspecialties neurocritical care fellowship program directors, and members of the Neurocritical Care Society.

RESULTS

A total of 268 neurocritical care providers and neurology residents from 30 institutions responded. Overall, >90% supported NCC graduates independently interpreting and managing systemic and cerebral hemodynamic data, or performing brain death determination, neurovascular ultrasound, vascular access, and airway management. Over 75% endorsed that NCC graduates should independently interpret EEG and perform bronchoscopies. Fewer but substantial respondents supported graduates being independent performing intracranial bolt (45.8%), ventriculostomy (39.0%), tracheostomy (39.8%), or gastrostomy (19.1%) procedures. Trainees differed from physicians and program directors, respectively, by advocating independence in EEG interpretation (92.8%, 61.8%, and 65.3%) and PEG placement (29.3%, 9.1%, and 8.5%).

CONCLUSIONS

Broad support exists across NCC role groups for wide-ranging NCC competencies including skills often performed by other neurology and non-neurology subspecialties. Variations highlight natural divergences in expectations among trainee, physician, and nurse role groups. These results establish expectations for core competencies within NCC and initiate dialogue across subspecialties about best practice standards for the spectrum of critically ill patients requiring neurologic care.

Time-Dependent Changes in Microglia Transcriptional Networks Following Traumatic Brain Injury

The neuroinflammatory response to traumatic brain injury (TBI) is critical to both neurotoxicity and neuroprotection, and has been proposed as a potentially modifiable driver of secondary injury in animal and human studies. Attempts to broadly target immune activation have been unsuccessful in improving outcomes, in part because the precise cellular and molecular mechanisms driving injury and outcome at acute, subacute, and chronic time points after TBI remain poorly defined. Microglia play a critical role in neuroinflammation and their persistent activation may contribute to long-term functional deficits. Activated microglia are characterized by morphological transformation and transcriptomic changes associated with specific inflammatory states. We analyzed the temporal course of changes in inflammatory genes of microglia isolated from injured brains at 2, 14, and 60 days after controlled cortical impact (CCI) in mice, a well-established model of focal cerebral contusion. We identified a time dependent, injury-associated change in the microglial gene expression profile toward a reduced ability to sense tissue damage, perform housekeeping, and maintain homeostasis in the early stages following CCI, with recovery and transition to a specialized inflammatory state over time. This later state starts at 14 days post-injury and is characterized by a biphasic pattern of IFNγ, IL-4, and IL-10 gene expression changes, with concurrent proinflammatory and anti-inflammatory gene changes. Our transcriptomic data sets are an important step to understand microglial role in TBI pathogenesis at the molecular level and identify common pathways that affect outcome. More studies to evaluate gene expression at the single cell level and focusing on subacute and chronic timepoint are warranted.

Stimulant Therapy in Acute Traumatic Brain Injury: Prescribing Patterns and Adverse Event Rates at 2 Level 1 Trauma Centers

BACKGROUND/OBJECTIVE

Pharmacological stimulant therapies are routinely administered to promote recovery in patients with subacute and chronic disorders of consciousness (DoC). However, utilization rates and adverse drug event (ADE) rates of stimulant therapies in patients with acute DoC are unknown. We aimed to determine the frequency of stimulant use and associated ADEs in intensive care unit (ICU) patients with acute DoC caused by traumatic brain injury (TBI).

METHODS

We retrospectively identified patients with TBI admitted to the ICU at 2 level 1 trauma centers between 2015 and 2018. Patients were included if they were stimulant naive at baseline and received amantadine, methylphenidate, or modafinil during ICU admission. Stimulant dose reduction or discontinuation during ICU admission was considered a surrogate marker of an ADE. Targeted chart review was performed to identify reasons for dose reduction or discontinuation.

RESULTS

Forty-eight of 608 patients with TBI received pharmacological stimulant therapy (7.9%) during the study period. Most patients were diagnosed with severe TBI at presentation (60.4%), although stimulants were also administered to patients with moderate (14.6%) and mild (25.0%) TBI. The median time of stimulant initiation was 11 days post-injury (range: 2-28 days). Median Glasgow Coma Scale score at the time of stimulant initiation was 9 (range: 4-15). Amantadine was the most commonly prescribed stimulant (85.4%) followed by modafinil (14.6%). Seven (14.6%) patients required stimulant dose reduction or discontinuation during ICU admission. The most common ADE resulting in therapy modification was delirium/agitation (n = 2), followed by insomnia (n = 1), anxiety (n = 1), and rash (n = 1); the reason for therapy modification was undocumented in 2 patients.

CONCLUSIONS

Pharmacological stimulant therapy is infrequently prescribed but well tolerated in ICU patients with acute TBI at level 1 trauma centers. These retrospective observations provide the basis for prospective studies to evaluate the safety, optimal dose range, and efficacy of stimulant therapies in this population.