Risk score for identifying adults with CSF pleocytosis and negative CSF Gram stain at low risk for an urgent treatable cause

Characterization and diagnosis spectrum of patients with cerebrospinal fluid pleocytosis

PURPOSE

There is an overlap in the cerebrospinal fluid (CSF) characteristics of patients presenting with different etiologies of CSF pleocytosis. Here, we characterized patients with CSF pleocytosis treated in a large hospital.

METHODS

A retrospective cohort study of 1150 patients with an elevated CSF leukocyte count > 5 cells/µl treated at a university hospital in Germany from January 2015 to December 2017 was performed. Information on clinical presentation, laboratory parameters, diagnosis and outcome was collected. Clinical and laboratory features were tested for their potential to differentiate between bacterial meningitis (BM) and other causes of CSF pleocytosis.

RESULTS

The most common etiologies of CSF pleocytosis were CNS infections (34%: 20% with detected pathogen, 14% without), autoimmune (21%) and neoplastic diseases (16%). CSF cell count was higher in CNS infections with detected pathogen (median 82 cells/µl) compared to autoimmune (11 cells/µl, p = 0.001), neoplastic diseases (19 cells/µl, p = 0.01) and other causes (11 cells/µl, p < 0.001). The CHANCE score was developed to differentiate BM from other causes of CSF pleocytosis: Multivariate regression revealed that CSF cell count > 100 cells/µl, CSF protein > 100 mg/dl, CRP > 5 mg/dl, elevated white blood cell count, abnormal mental status and nuchal rigidity are important indicators. The CHANCE score identified patients with BM with high sensitivity (92.1%) and specificity (90.9%) (derivation cohort: AUC: 0.955, validation cohort: AUC: 0.956).

CONCLUSION

Overall, the most common causes for CSF pleocytosis include infectious, neoplastic or autoimmune CNS diseases in ~ 70% of patients. The CHANCE score could be of help to identify patients with high likelihood of BM and support clinical decision making.

Progress and Challenges in Bacterial Meningitis: A Review

IMPORTANCE

Bacterial meningitis is a worldwide health problem, with incidence rates ranging from approximately 0.9 per 100 000 individuals per year in high-income countries to 80 per 100 000 individuals per year in low-income countries. In low-income countries, bacterial meningitis has a mortality rate of up to 54%. Up to 24% of those who survive develop chronic neurological sequelae, such as hearing loss or focal neurological deficits.

OBSERVATIONS

Streptococcus pneumoniae causes about 72% and Neisseria meningitidis causes about 11% of cases of bacterial meningitis in people older than 16 years. Escherichia coli and Streptococcus agalactiae cause about 35% of cases of early-onset neonatal meningitis. In adults, risk factors for bacterial meningitis include older age and immunosuppressive conditions. The most common symptoms are headache (84%), fever (74%), stiff neck (74%), altered mental status (median [IQR] Glasgow Coma Scale score of 11 [9-14] on a scale ranging from 3-15), and nausea (62%). Brain imaging should be performed before lumbar puncture if patients present with altered mental status, focal neurological deficits, papilledema, or history of immunocompromising conditions or central nervous system disease. Bacterial meningitis should be suspected if any of the following are present on admission: serum leukocytes greater than 10.0 ×109/L, cerebrospinal fluid (CSF) leukocytes greater than 2000/μL, CSF granulocytes greater than 1180/μL, CSF protein greater than 2.2 g/L, CSF glucose less than 34.23 mg/dL, or fever. A positive Gram stain result for bacteria is diagnostic, but the sensitivity of a positive Gram stain result for bacterial meningitis ranges from 50% to 90%. In countries in which the prevalence of ceftriaxone-resistant Streptococcus pneumoniae exceeds 1%, vancomycin and ceftriaxone are the empirical antibiotics of choice, with the addition of ampicillin in neonates, older patients, and immunocompromised patients. Adjunctive dexamethasone should be used in patients with bacterial meningitis but stopped if Listeria monocytogenes is confirmed.

CONCLUSIONS AND RELEVANCE

Bacterial meningitis affects approximately 0.9 per 100 000 individuals to 80 per 100 000 individuals per year and has a mortality rate as high as 54%. First-line therapy is prompt empirical intravenous antibiotic therapy and adjunctive dexamethasone.

Fc-MBL-modified Fe3O4 magnetic bead enrichment and fixation in Gram stain for rapid detection of low-concentration bacteria

Functional bacterial enrichment magnetic beads (Fe₃O₄@SiO₂@Fc-MBL) and Gram staining were combined for the fast diagnosis of infecting bacteria in meningitis. Fe₃O₄@SiO₂@Fc-MBL has excellent microbial binding ability and can be used for bacterial enrichment from cerebrospinal fluid (CSF). The enriched bacteria are recognized by Gram stain at very low concentrations (10 CFU·mL^-1). The feasibility of this method was verified by five common bacteria in meningitis infection (Gram-positive: Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus capitis; Gram-negative: Klebsiella pneumoniae and Escherichia coli). The extraction efficiency of Fc-MBL-modified Fe₃O₄ magnetic beads was approximately 90% in artificial CSF for the selected bacteria, with the exception of E. coli (~ 60%). The bacteria were successfully recognized by Gram staining and microscopic observation. Fe₃O₄@SiO₂@Fc-MBL acts by capturing and fixing the bacteria in a magnetic field throughout the experiment. Compared with traditional CSF Gram staining, this new method avoids interference by inflammatory cells and red blood cells during microscopic examination. Furthermore, the sensitivity of this method is much better than the centrifugation smear method. The whole process can be accomplished within 30 min. This novel method may have potential as a clinical tool for analysis of bacteria in the CSF.

Impact of a Multiplex Polymerase Chain Reaction Panel on Duration of Empiric Antibiotic Therapy in Suspected Bacterial Meningitis

Background

Multiplex polymerase chain reaction (PCR) panels allow for rapid detection or exclusion of pathogens causing meningitis and encephalitis (ME). The clinical impact of rapid multiplex PCR ME panel results on the duration of empiric antibiotic therapy is not well characterized.

Methods

We performed a retrospective prepost study at our institution that evaluated the clinical impact of a multiplex PCR ME panel among adults with suspected bacterial meningitis who received empiric antibiotic therapy and underwent lumbar puncture in the emergency department. The primary outcome was the duration of empiric antibiotic therapy.

Results

The positive pathogen detection rates were similar between pre- and post-multiplex PCR ME panel periods (17.5%, 24 of 137 vs 20.3%, 14 of 69, respectively). The median duration of empiric antibiotic therapy was significantly reduced in the post-multiplex PCR ME panel period compared with the pre-multiplex PCR ME panel period (34.7 vs 12.3 hours, P = .01). At any point in time, 46% more patients in the post-multiplex PCR ME panel period had empiric antibiotic therapy discontinued or de-escalated compared with the pre-multiplex PCR ME panel period (sex- and immunosuppressant use-adjusted hazard ratio 1.46, P = .01). The median hospital length of stay was shorter in the post-multiplex PCR ME panel period (3 vs 4 days, P = .03).

Conclusions

The implementation of the multiplex PCR ME panel for bacterial meningitis reduced the duration of empiric antibiotic therapy and possibly hospital length of stay compared with traditional microbiological testing methods.

Point-of-care cerebrospinal fluid Gram stain for the management of acute meningitis in adults: a retrospective observational study

Background

Gram stain of cerebrospinal fluid (CSF) is widely used in the diagnosis of acute meningitis, however, it is often conducted in the laboratory, as only some hospitals have access to point-of-care Gram stain (PCGS). The purpose of this study was to demonstrate the clinical impact and utility of PCGS in diagnosing and treating both bacterial and aseptic meningitis in adults.

Methods

This was a hospital-based, retrospective observational study at a referral center in Okinawa, Japan. We reviewed the records of all patients aged 15 years or older who were admitted to the Division of Infectious Diseases between 1995 and 2015 and finally diagnosed with bacterial (n = 34) or aseptic meningitis (n = 97). For bacterial meningitis, we compared the treatments that were actually selected based on PCGS with simulated treatments that would have been based on the Japanese guidelines. For aseptic meningitis, we compared the rates of antibiotic use between real cases where PCGS was available and real cases where it was not.

Results

PCGS was the most precise predictor for differentiating between bacterial and aseptic meningitis (sensitivity 91.2%, specificity 98.9%), being superior in this regard to medical histories, vital signs and physical examinations, and laboratory data available in the emergency room (ER). In bacterial meningitis, PCGS reduced the frequency of meropenem use (1/34 = 3.0%) compared with simulated cases in which PCGS was not available (19/34 = 55.9%) (p< 0.001). In aseptic meningitis cases, the rate of antibiotic administration was lower when PCGS was used (38/97 = 39.2%) than when it was not (45/74 = 60.8%) (p = 0.006).

Conclusions

PCGS of CSF distinguishes between bacterial and aseptic meningitis more accurately than other predictors available in the ER. Patients with bacterial meningitis are more likely to receive narrower-spectrum antimicrobials when PCGS is used than when it is not. PCGS of CSF thus can potentially suppress the empiric use of antimicrobials for aseptic meningitis.

Management of Acute Bacterial Meningitis in Children

Acute community-acquired bacterial meningitis (ABM) in children continues to have high rates of neurological morbidity and mortality despite the overall declining rates of infection attributed to the use of vaccines and intrapartum Group B Streptococcus prophylaxis. Prompt diagnosis and early antibiotic therapy are crucial and should not be delayed to obtain cranial imaging. Differentiating bacterial from viral meningitis continues to be a clinical dilemma especially in patients with previous antibiotic exposure. Clinical models and inflammatory biomarkers can aid clinicians in their diagnostic approach. Multiplex polymerase chain reaction and metagenomic next-generation sequencing are promising tools that can help in early and accurate diagnosis. This review will present the epidemiology of ABM in children, indications of cranial imaging, role of different models and serum biomarkers in diagnosing ABM, and management including the use of adjunctive therapies and methods of prevention.

Update and advances in community acquired bacterial meningitis

PURPOSE OF REVIEW

Community-acquired bacterial meningitis continues to occur and be associated with significant morbidity and mortality despite the availability of effective conjugate vaccines for the three most important meningeal pathogens.

RECENT FINDINGS

Indications for cranial imaging in suspected bacterial meningitis varies significantly between guidelines. Cranial imaging is of no clinical utility in those patients without indications and fosters delays in performing a lumbar puncture. Delaying lumbar puncture is associated with increased costs in both adults and children with meningitis and previous antibiotic therapy impacts the yield of microbiological results. Delaying antibiotic therapy is associated with worse clinical outcomes. Adjunctive steroids have reduced the mortality of adults with pneumococcal meningitis but have been associated with increased adverse outcomes in Listeria monocytogenes and Cryptococcus neoformans.

SUMMARY

Community-acquired bacterial meningitis remains a global health concern with high morbidity and mortality especially in low-income countries. Cranial imaging should be done only in patients with an indication with an attempt to do a prompt lumbar puncture and to initiate antibiotic therapy and adjunctive steroids as soon as possible to improve clinical outcomes.

Validation of the Bacterial Meningitis Score in adults consulting at an emergency department: a retrospective multicentric study

OBJECTIVE

The Bacterial Meningitis Score (BMS) is recommended by pediatric academic societies to rule out the diagnosis of bacterial meningitis. The aim of this study was to evaluate the performance of the BMS to identify adults at no risk for bacterial meningitis.

METHODS

We conducted a multicentric retrospective study including adults who consulted the emergency department (ED) for meningitis [cerebrospinal fluid (CSF) white blood cells ≥5/mm with a ratio of white blood cells/red blood cells <1:900) during a 4-year period. The BMS variables were: CSF positive Gram stain, CSF absolute neutrophil count ≥1000 cells/μL, CSF protein ≥80 mg/dL, peripheral blood absolute neutrophil count ≥10 000 cells/μL, and seizures. Bacterial meningitis was defined for patients who had a lumbar puncture with CSF pleocytosis and positive bacterial analysis of CSF. The primary endpoint was the sensitivity of the BMS to rule out bacterial meningitis in adults. The secondary outcome was to assess the rate of patients for whom antibiotics could have been avoided using the BMS and the diagnostic performance of procalcitonin in patients with a BMS ≥1.

RESULTS

Of 930 patients with meningitis, 626 were included in the analysis, and 27 (4.3%) were diagnosed with bacterial meningitis. A total of 384/626 (61.3%) patients had a BMS = 0, and none presented bacterial meningitis. BMS sensitivity was 100% [95% confidence interval (CI), 87.2-100%], and its negative predictive values were 100% (95% CI, 98.8-100%).

CONCLUSION

Among patients with a diagnosis of meningitis in ED, a BMS of 0 may safely rule out bacterial meningitis.

Cost of managing meningitis and encephalitis among infants and children in the United States

A retrospective cohort study design was used to assess the use and costs of diagnostic tests, medication, and total hospitalization costs for pediatric patients with suspected meningitis/encephalitis who received a lumbar puncture (LP) procedure. Related costs were calculated by timing of LP performed and infectious etiology for infants (<1 year) and children (1-17 years). A total of 3030 infants and 3635 children with suspected ME diagnosed between 2011 and 2014 were included in the study. The mean hospitalization cost for infants and children was $12,759 and $11,119, respectively, with medication and laboratory test costs of $834 and $1771 for infants and $825 and $855 for children, respectively. Total visit cost increased with delayed LP procedure, ICU stay, and if the etiology was viral (other than enterovirus or arbovirus) or bacterial. Higher diagnostic and treatment costs were associated with delayed LP procedure, etiologic agent, and ICU stay.

Epidemiology of Meningitis and Encephalitis in the United States, 2011-2014

Background

Large epidemiological studies evaluating the etiologies, management decisions, and outcomes of adults with meningitis or encephalitis in the United States (US) are lacking.

Methods

Adult patients (≥18 years) with meningitis or encephalitis by International Classification of Diseases, Ninth Revision codes available in the Premier Healthcare Database during 2011-2014 were analyzed.

Results

A total of 26429 patients with meningitis or encephalitis were identified. The median age was 43 years; 53% were female. The most common etiology was enterovirus (13463 [51.6%]), followed by unknown (4944 [21.4%]), bacterial meningitis (3692 [14.1%]), herpes simplex virus (2184 [8.3%]), noninfectious (921 [3.5%]), fungal (720 [2.7%]), arboviruses (291 [1.1%]), and other viruses (214 [0.8%]). Empiric antibiotics, antivirals, and antifungals were administered in 85.8%, 53.4%, and 7.8%, respectively, and varied by etiologies. Adjunctive steroids were utilized in 15.9% of all patients and in 39.3% of patients with pneumococcal meningitis, with an associated decrease in mortality (6.67% vs 12.5%, P = .0245). The median length of stay was 4 days, with the longest duration in those with fungal (13), arboviral (10), and bacterial meningitis (7). Overall inpatient mortality was 2.9% and was higher in those with bacterial (8.2%), fungal (8.2%), or arboviral (8.9%) disease. Overall readmission rate at 30 days was 3.2%; patients with arboviral (12.7%), bacterial (6.7%), and fungal (5.4%) etiologies had higher rates.

Conclusions

Viruses are the most common cause of meningitis and encephalitis in the United States and are treated with antibiotic therapy in the majority of cases. Adjunctive steroid treatment is underutilized in pneumococcal meningitis, where it has shown to decrease mortality.

Aseptic meningitis in adults and children: Diagnostic and management challenges

BACKGROUND

Aseptic meningitis represents a common diagnostic and management dilemma to clinicians.

OBJECTIVES

To compare the clinical epidemiology, diagnostic evaluations, management, and outcomes between adults and children with aseptic meningitis.

STUDY DESIGN

We conducted a retrospective study from January 2005 through September 2010 at 9 Memorial Hermann Hospitals in Houston, TX. Patients age≥2months who presented with community-acquired aseptic meningitis with a CSF white blood cell count >5cells/mm³ and a negative Gram stain and cultures were enrolled. Patients with a positive cryptococcal antigen, positive blood cultures, intracranial masses, brain abscesses, or encephalitis were excluded.

RESULTS

A total of 509 patients were included; 404 were adults and 105 were children. Adults were most likely to be female, Caucasian, immunosuppressed, have meningeal symptoms (headache, nausea, stiff neck, photophobia) and have a higher CSF protein (P <0.05). In contrast, children were more likely to have respiratory symptoms, fever, and leukocytosis (P <0.05). In 410 (81%) patients, the etiologies remained unknown. Adults were more likely to be tested for and to have Herpes simplex virus and West Nile virus while children were more likely to be tested for and to have Enterovirus (P <0.001). The majority of patients were admitted (96.5%) with children receiving antibiotic therapy more frequently (P <0.001) and adults receiving more antiviral therapy (P=0.001). A total of 384 patients (75%) underwent head CT scans and 125 (25%) MRI scans; all were normal except for meningeal enhancement. All patients had a good clinical outcome at discharge.

DISCUSSION

Aseptic meningitis in adults and children represent a management challenge as etiologies remained unknown for the majority of patients due to underutilization of currently available diagnostic techniques.

Cerebrospinal fluid pleocytosis in infectious and noninfectious central nervous system disease: A retrospective cohort study

Cerebrospinal fluid (CSF) analysis is the most important tool for assessing central nervous system (CNS) disease. An elevated CSF leukocyte count rarely provides the final diagnosis, but is almost always an indicator of inflammation within the CNS.The present study investigated the variety of diseases associated with CSF pleocytosis.CSF analyses were identified through the biochemical database used in the capital region of Denmark in the period from 2003 to 2010. In patients >15 years, clinical diagnoses associated with the finding of a CSF leukocyte count >10 × 10 cells/L were obtained from discharge records and patient files.A total of 1058 CSF samples from 1054 patients were included in the analysis. The median age was 50 (interquartile range: 36-67) and 53% were male. Eighty-one different diagnoses were identified in 1058 cases with an elevated CSF leukocyte count, besides unknown causes. Infections were the most common cause of CSF pleocytosis (61.4%) followed by miscellaneous causes (12.7%), vascular (9.7%), neurodegenerative (7%), neoplastic (5%), and inflammatory conditions (4.2%). Only infections presented with leukocyte counts >10,000 × 10/L. Infections represented 82.6% of all cases with a leukocyte count >100 × 10/L whereas 56.3% of cases with at leukocyte counts <100 × 10/L were dominated by disease not related to infection.The present study may serve as a reminder to clinicians of what diseases and disease categories to suspect when patients present with CSF biochemistry indicating CNS inflammation.

Community-acquired bacterial meningitis

Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma (nosocomial bacterial meningitis). Despite advances in treatment and vaccinations, community-acquired bacterial meningitis remains one of the most important infectious diseases worldwide. Streptococcus pneumoniae and Neisseria meningitidis are the most common causative bacteria and are associated with high mortality and morbidity; vaccines targeting these organisms, which have designs similar to the successful vaccine that targets Haemophilus influenzae type b meningitis, are now being used in many routine vaccination programmes. Experimental and genetic association studies have increased our knowledge about the pathogenesis of bacterial meningitis. Early antibiotic treatment improves the outcome, but the growing emergence of drug resistance as well as shifts in the distribution of serotypes and groups are fuelling further development of new vaccines and treatment strategies. Corticosteroids were found to be beneficial in high-income countries depending on the bacterial species. Further improvements in the outcome are likely to come from dampening the host inflammatory response and implementing preventive measures, especially the development of new vaccines.

Gender Differences in Community-acquired Meningitis in Adults: Clinical Presentations and Prognostic Factors

Community-acquired meningitis is a serious disease that is associated with high morbidity and mortality. The purpose of this study was to investigate the gender differences involved with the clinical presentations of and prognostic factors for this disease. We conducted a retrospective study of 619 adults diagnosed with community-acquired meningitis in Houston, Texas, who were hospitalized between 2005 and 2010. Patients were categorized as male or female. Those who were evaluated to have a Glasgow Outcome Scale score of four or less were classified to have an adverse clinical outcome. Males consisted of 47.2% (292/619) of the total cohort, and more often presented with coexisting medical conditions, fever, abnormal microbiology results, and abnormalities on head computed tomography. Females more often presented with nuchal rigidity. On logistic regression, fever, CSF glucose <45 mg/dL, and an abnormal neurological examination were predictors of an adverse outcome in male patients, while age greater than 60 years and an abnormal neurological examination were associated with a poor prognosis in female patients. Thus, community-acquired meningitis in males differs significantly from females in regards to comorbidities, presenting symptoms and signs, abnormal laboratory and imaging analysis, and predictors of adverse clinical outcomes.

The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults

Bacterial meningitis and meningococcal sepsis are rare conditions with high case fatality rates. Early recognition and prompt treatment saves lives. In 1999 the British Infection Society produced a consensus statement for the management of immunocompetent adults with meningitis and meningococcal sepsis. Since 1999 there have been many changes. We therefore set out to produce revised guidelines which provide a standardised evidence-based approach to the management of acute community acquired meningitis and meningococcal sepsis in adults. A working party consisting of infectious diseases physicians, neurologists, acute physicians, intensivists, microbiologists, public health experts and patient group representatives was formed. Key questions were identified and the literature reviewed. All recommendations were graded and agreed upon by the working party. The guidelines, which for the first time include viral meningitis, are written in accordance with the AGREE 2 tool and recommendations graded according to the GRADE system. Main changes from the original statement include the indications for pre-hospital antibiotics, timing of the lumbar puncture and the indications for neuroimaging. The list of investigations has been updated and more emphasis is placed on molecular diagnosis. Approaches to both antibiotic and steroid therapy have been revised. Several recommendations have been given regarding the follow-up of patients.

Epidemiology of meningitis with a negative CSF Gram stain: under-utilization of available diagnostic tests

Meningitis with a negative cerebrospinal fluid Gram stain (CSF-GS) poses a diagnostic challenge as more than 50% of patients remain without an aetiology. The introduction of polymerase chain reaction (PCR) and arboviral serologies have increased diagnostic capabilities, yet large scale epidemiological studies evaluating their use in clinical practice are lacking. We conducted a prospective observational study in New Orleans between November 1999 and September 2008 (early era) when PCR was not widely available, and in Houston between November 2008 and June 2013 (modern era), when PCR was commonly used. Patients presenting with meningitis and negative CSF-GS were followed for 4 weeks. All investigations, PCR used, and results were recorded as they became available. In 323 patients enrolled, PCR provided the highest diagnostic yield (24·2%) but was ordered for 128 (39·6%) patients; followed by serology for arboviruses (15%) that was ordered for 100 (31%) of all patients. The yield of blood cultures was (10·3%) and that of CSF cultures was 4%; the yield for all other tests was <10%. Overall, 65% of the patients remained without a diagnosis at 4 weeks: 72·1% in early era vs. 53·4% (P < 0·01) in modern era; this change was attributed to diagnosing more viral pathogens, 8·3% and 26·3% (P < 0·01), respectively. The introduction of PCR and arboviral serologies has improved the yield of diagnosing patients with meningitis and a negative CSF-GS, but both tests are being under-utilized.

Community-acquired meningitis in older adults: clinical features, etiology, and prognostic factors

OBJECTIVES

To investigate the epidemiology and outcomes of community-acquired meningitis in older adults.

DESIGN

Retrospective study.

SETTING

Participants adults in Houston, Texas, with community-acquired meningitis hospitalized between January 1, 2005, and January 1, 2010 (N = 619; n = 54, 8.7%, aged ≥65; n = 565 aged <65).

METHODS

An adverse clinical outcome was defined as a Glasgow Outcome Scale score of 4 or less.

RESULTS

Older adults had higher rates of comorbidities, abnormal neurological and laboratory (serum white blood cell count >12,000/μL, and cerebrospinal fluid protein >100 mg/dL) findings (P < .001), abnormalities on computed tomography and magnetic resonance imaging of the head (P = .002), and adverse clinical outcomes (ACOs) (P < .001). The majority of participants (65.8%) had meningitis of unknown etiology. Bacterial meningitis was an infrequent cause of community-acquired meningitis (7.4%). Of the known causes, bacterial meningitis and West Nile virus were more common in older than younger adults; younger participants more frequently had cryptococcal and viral meningitis. On logistic regression, female sex was predictive of a poor outcome in the older participants (P = .002), whereas abnormal neurological examination (P < .001), fever (P = .01), and a cerebrospinal fluid glucose level less than 45 mg/dL (P = .002) were significant poor prognostic factors in younger participants.

CONCLUSION

Most cases of community-acquired meningitis are of unknown origin. Older adults are more likely than younger adults to have bacterial meningitis and West Nile virus infection when a cause can be identified. They also have more neurological abnormalities, laboratory and imaging abnormalities, and adverse clinical outcomes.