Bacterial meningitis

Does CSF pleocytosis have a predictive value for disease course in MS?

Objective

MS is a demyelinating CNS disorder with a spectrum of clinical patterns regarding course and prognosis. Although several prognostic factors are considered in the initial evaluation of patients, biological markers defining the disease course and guiding treatments are currently lacking. It is unknown whether patients with CSF pleocytosis differ in regard to symptoms, disease course, and prognosis from those without. The aim of this study was to evaluate whether CSF pleocytosis during the initial presentation has an impact on the clinical course and progression of MS.

Methods

We retrospectively evaluated patients attending the MS Clinic at Rabin Medical Center between January 1999 and January 2016 who underwent lumbar puncture (LP) at disease presentation, considering CSF cell count, clinical diagnosis (clinically isolated syndrome [CIS] and relapsing-remitting MS [RRMS]), annualized relapse rate (ARR), paraclinical findings (imaging, CSF oligoclonal bands, and evoked potentials), and disease progression, expressed by the Expanded Disability Status Scale (EDSS).

Results

One hundred fourteen patients (72 females) underwent LP at disease presentation (RRMS: n = 100, CIS: n = 14). Age at diagnosis was 32.4 ± 12.2 years, and the follow-up time was 9.4 ± 3.8 years. Forty-six patients showed a pleocytic CSF (≥5 cells per μL). Compared with patients with <4 cells per μL, patients with pleocytosis had a higher ARR (0.60 ± 0.09 vs 0.48 ± 0.04; p = 0.0267) and a steeper increase (slope) in the EDSS score throughout the follow-up period (correlation coefficient: r2 = 0.04; p = 0.0251).

Conclusions

CSF pleocytosis may be considered a biological unfavorable predictive factor regarding disease course and progression in MS.

Central Nervous System Infections in the Critically Ill

Central nervous system (CNS) infections are frequently encountered in the intensive care unit setting and are a significant source of morbidity and mortality. The constantly changing trends in microbial resistance, as well as the pharmacokinetic difficulties in providing effective concentrations of antimicrobials at the site of infection represent a unique challenge to clinicians. Achievement of a successful outcome in patientswith CNS infections is reliant on eradication of the offending pathogen and management of any neurologic complications. This requires an anatomic and physiologic understanding of the different types of CNS infection, diagnostic strategies, associated complications, causative organisms, and the principles that govern drug distribution into the CNS. This article serves as a review of the epidemiology, pathophysiology, diagnosis, and treatment options for a variety of CNS infections, with a focus on those commonly encountered in an intensive care setting.

Prevention and treatment of penicillin-resistant Streptococcus pneumoniae meningitis after intracraniofacial surgery with distraction osteogenesis

The prevalence of penicillin-resistant Streptococcus pneumoniae (PRSP) meningitis has increased worldwide, particularly in East Asia and the United States. We recently experienced a case of PRSP meningitis that developed during frontofacial distraction. The patient was a 7-year-old girl with Crouzon disease who was treated by frontofacial monobloc/Le Fort IV minus glabellar osteotomy with quadruple internal distraction devices. Penicillin-resistant Streptococcus pneumoniae meningitis was diagnosed after surgery and treated successfully with meropenem (a carbapenem) at 120 mg kg d every 8 hours, ceftriaxone (a third-generation cephalosporin) at 100 mg kg d every 12 hours, and vancomycin (a glycopeptide) at 45 mg kg d every 6 hours. This case indicates that severe and fatal bacterial meningitis may occur as a postoperative complication due to multidrug-resistant bacteria indigenous to the nasal cavity after simultaneous osteotomy of the cranium and facial bone in intracraniofacial surgery, such as that for syndromic craniosynostosis and hypertelorbitism. In such cases, preventive strategies should include preoperative administration of pneumococcal vaccine, preoperative screening of nasal bacterial flora by nasal culture test, and prior administration of a carbapenem with good cerebrospinal fluid transfer or a third- or fourth-generation cephem covering PRSP. Postoperatively, suspected meningitis may be treated with a combination of the 3 drugs used in our case, in parallel with emergency cephalic contrast computed tomography and culture tests of blood and cerebrospinal fluid. Our experience suggests that these measures will facilitate a successful outcome in frontofacial distraction osteogenesis.

Central nervous system infections in the neurointensive care unit

Central nervous system (CNS) infections are frequently encountered at the primary care level, in emergency rooms, medical wards, and intensive care units. Advances in immunization techniques and aggressive prevention campaigns have had an impact on the worldwide incidence of community-acquired meningitis, limiting this disease to the adult population. In general, a high index of suspicion is required for the diagnosis, but special attention should be given to the immunocompromised host and post-neurosurgical patient in whom the clinical presentation may be nonspecific. Once the diagnosis is made, broad-spectrum antimicrobials should be administered, followed by diagnostic testing, and targeted antibiotic therapy. Current guidelines for the treatment of meningitis are clinically effective but are not based on randomized, prospective, controlled trials. Despite current therapies, the morbidity of CNS infections is still devastating. Recent trials of the use of corticosteroids as coadjuvants of antibiotic therapy showed promising results and decrease in the morbidity associated with bacterial and tuberculous meningitis. Additional neuroprotective alternatives should be the focus of future research. Similarly, guidelines for the diagnosis and management of post-neurosurgical procedure meningitis and ventriculostomy-related infections are needed.

Marked elevation of cerebrospinal fluid white blood cell count: An unusual case of Streptococcus pneumoniae meningitis, differential diagnosis, and a brief review of current epidemiology and treatment recommendations

The diagnosis of bacterial meningitis is rarely a difficult diagnostic dilemma when a patient presents with fever, headache, neck stiffness, and altered mental status. Unfortunately for the practicing clinician, patients are rarely that straightforward. Patients who are elderly, very young, or immuno-compromised often present with subtle findings, making the correct diagnosis a challenge. In addition, patients being treated with antibiotics may be misleading in their clinical presentation, leading to a missed diagnosis of meningitis. Only when one considers the diagnosis or obtains a sample of cerebrospinal fluid is the correct diagnosis made. Although the clinical scenario may suggest meningitis, it is the cerebrospinal fluid white blood cell count that establishes the definitive diagnosis. Despite the advent of systemic antibiotics over 50 years ago, bacterial meningitis continues to cause considerable morbidity and mortality worldwide. The following case report details a woman diagnosed with Streptococcus pneumoniae meningitis with an extremely high cerebrospinal white blood cell count. Although this is typically thought to be caused by abscesses or malignancy, meningitis alone may cause such an elevation. In addition, a brief review of the current epidemiology and treatment regimens for meningitis is discussed.

Aquaporin-4 gene disruption in mice reduces brain swelling and mortality in pneumococcal meningitis

The astroglial water channel aquaporin-4 (AQP4) facilitates water movement into and out of brain parenchyma. To investigate the role of AQP4 in meningitis-induced brain edema, Streptococcus pneumoniae was injected into cerebrospinal fluid (CSF) in wild type and AQP4 null mice. AQP4-deficient mice had remarkably lower intracranial pressure (9 +/- 1 versus 25 +/- 5 cm H2O) and brain water accumulation (2 +/- 1 versus 9 +/- 1 microl) at 30 h, and improved survival (80 versus 0% survival) at 60 h, through comparable CSF bacterial and white cell counts. Meningitis produced marked astrocyte foot process swelling in wild type but not AQP4 null mice, and slowed diffusion of an inert macromolecule in brain extracellular space. AQP4 protein was strongly up-regulated in meningitis, resulting in a approximately 5-fold higher water permeability (P(f)) across the blood-brain barrier compared with non-infected wild type mice. Mathematical modeling using measured P(f) and CSF dynamics accurately simulated the elevated lower intracranial pressure and brain water produced by meningitis and predicted a beneficial effect of prevention of AQP4 upregulation. Our findings provide a novel molecular mechanism for the pathogenesis of brain edema in acute bacterial meningitis, and suggest that inhibition of AQP4 function or up-regulation may dramatically improve clinical outcome.

Rapid infectious killers

Central to the practice of emergency medicine is the ability to identify patients in whom immediate intervention is needed to prevent long-term morbidity and mortality. This article has highlighted some of the characteristics of several infectious diseases that may become fatal quickly if not treated quickly and appropriately by physicians. Bacterial meningitis,necrotizing soft tissue infections, invasive gram-negative disease, pneumo-coccal pneumonia, and West Nile encephalitis all require prompt recognition and treatment by emergency care providers.

Meningitis and encephalitis in children. An update

Over the course of the past decade, much has changed on the landscape of meningitis and encephalitis in children. West Nile virus has emerged in the United States as a new etiologic pathogen causing encephalitis. Human herpesvirus-6 has been identified as a cause of encephalitis and febrile seizures. Lymphocytic choriomeningitis virus has been identified as an underrecognized neuroteratogen. The emergence of penicillin-resistant Streptococcus pneumoniae has complicated the treatment of bacterial meningitis, whereas the Haemophilus influenzae vaccine has fundamentally altered the disease's epidemiology. The recognition that much of the neuropathologic change induced by bacterial meningitis is inflammation mediated has paved the way to the demonstration that dexamethasone can substantially improve the outcome of bacterial meningitis in children. Although much progress has been made toward understanding, treating, and preventing these important infections, much remains to be learned.