Bacterial Infections of the Central Nervous System.

Acute bacterial meningitis and spinal epidural abscess are neurological emergencies. Acute bacterial meningitis may present with symptoms as nonspecific as headache and fever, but rapid progression to an altered level of consciousness is not unusual. Spinal epidural abscess manifests initially as back pain, followed by radicular pain, then weakness, and finally paraplegia. Brain abscess may initially present only with headache, or as a new-onset seizure or with a focal neurological deficit. Bacterial infections of the central nervous system require emergent diagnosis and management. In this article, the pathogenesis, etiological organisms, diagnostic studies, differential diagnosis and management of acute bacterial meningitis, spinal epidural abscess, and brain abscess are discussed.

Utility of measuring (1,3)-ß-d-glucan in cerebrospinal fluid for diagnosis of fungal central nervous system infection.

(1-3)-ß-d-Glucan (BDG) from cerebrospinal fluid (CSF) is a promising marker for diagnostic and prognostic aid of central nervous system (CNS) fungal infection, but its relationship to serum values has not been studied. Herein, we detected BDG from CSF at levels 2-fold lower than those in serum in patients without evidence of fungal disease but 25-fold higher than those in in serum in noncryptococcal CNS fungal infections. CSF BDG may be a useful biomarker in the evaluation of fungal CNS disease.

Spinal epidural abscess and paralytic mechanisms.

PURPOSE OF REVIEW: The incidence of spinal epidural abscess is increasing, and the understanding of the pathophysiology is evolving. Better understanding of the pathophysiology, specifically the role of ischemia, warrants a change in therapy. RECENT FINDINGS: Paralysis in spinal epidural abscess may be the result of spinal cord compression, spinal cord arterial and/or venous ischemia and thrombophlebitis or a combination of these. SUMMARY: Recent evidence indicates the following areas of investigation and management can improve outcome in spinal epidural abscess: minimally invasive surgery early versus medical management when there are no significant neurological deficits, neuroradiologic arterial evaluation with therapies directed at vascular ischemia and thrombosis, and aggressive rehabilitation.

Cerebrospinal fluid (1,3)-ß-D-glucan detection as an aid for diagnosis of iatrogenic fungal meningitis.

This case series highlights our experience with use of the Fungitell assay for quantifying (1,3)-ß-d-glucan in cerebrospinal fluid during the current U.S. outbreak of fungal meningitis related to contaminated methylprednisolone acetate. This test may prove a useful adjunct in diagnosis and management of exposed patients.

Neuroinfectious diseases in pregnancy.

Pregnancy is associated with impaired T-cell-mediated immunity putting the woman at risk for infectious diseases not typically seen in immunocompetent individuals. When maternal infection is severe, and when a primary herpesvirus infection is acquired during pregnancy, there is a risk of fetal loss, maternal death, neonatal death, or congenital abnormalities from intrauterine infection. In this review, the authors emphasize specific neurologic infectious diseases that occur in pregnancy, the safety of the antimicrobial therapy of these diseases during pregnancy, as well as the congenital and neonatal sequelae of infection.

Neurologic Complications of Lyme Disease.

PURPOSE OF REVIEW: This article reviews the symptomatology, diagnosis, and treatment of neuroborreliosis. RECENT FINDINGS: The most recent guidelines for the diagnosis and treatment of Lyme disease were published in 2020 by the Infectious Diseases Society of America, the American Academy of Neurology, and the American College of Rheumatology. SUMMARY: The most common neurologic complications of Lyme disease are cranial neuritis (most often a unilateral or bilateral facial nerve palsy), meningitis, and radiculoneuritis/mononeuropathy multiplex. Testing for Lyme disease begins with an enzyme-linked immunosorbent assay (ELISA). If the ELISA is positive or borderline, Western blots should be performed for both IgM and IgG antibodies. As a general rule, in infectious diseases, an IgM antibody response is followed by an IgG antibody response. A central nervous system infection has either a CSF pleocytosis or pathogen-specific intrathecal antibody production. Lyme meningitis, cranial neuropathy, radiculoneuropathy, or other peripheral nervous system manifestations are treated with oral doxycycline or IV ceftriaxone, cefotaxime, or penicillin G. No additional antibiotic therapy is indicated for patients with posttreatment Lyme disease syndrome or patients with concern for chronic Lyme disease with no evidence of previous or current Lyme infection.

Pearls: infectious diseases.

Neurologists have a great deal of knowledge of the classic signs of central nervous system infectious diseases. After years of taking care of patients with infectious diseases, several symptoms, signs, and cerebrospinal fluid abnormalities have been identified that are helpful time and time again in determining the etiological agent. These lessons, learned at the bedside, are reviewed in this article.

Building a neuroinfectious disease consensus curriculum.

OBJECTIVE: To delineate a comprehensive curriculum for fellowship training in neuroinfectious diseases, we conducted a modified Delphi approach to reach consensus among 11 experts in the field. METHODS: The authors invited a diverse range of experts from the American Academy of Neurology Neuro-Infectious Diseases (AAN Neuro-ID) Section to participate in a consensus process using a modified Delphi technique. RESULTS: A comprehensive list of topics was generated with 101 initial items. Through 3 rounds of voting and discussion, a curriculum with 83 items reached consensus. CONCLUSIONS: The modified Delphi technique provides an efficient and rigorous means to reach consensus on topics requiring expert opinion. The AAN Neuro-ID section provided the pool of diverse experts, the infrastructure, and the community through which to accomplish the consensus project successfully. This process could be applied to other subspecialties and sections at the AAN.

The management of encephalitis: clinical practice guidelines by the Infectious Diseases Society of America.

Guidelines for the diagnosis and treatment of patients with encephalitis were prepared by an Expert Panel of the Infectious Diseases Society of America. The guidelines are intended for use by health care providers who care for patients with encephalitis. The guideline includes data on the epidemiology, clinical features, diagnosis, and treatment of many viral, bacterial, fungal, protozoal, and helminthic etiologies of encephalitis and provides information on when specific etiologic agents should be considered in individual patients with encephalitis.

Meta-analysis: Cysticidal drugs for neurocysticercosis: albendazole and praziquantel.

BACKGROUND: Conflicting reports have caused controversy on whether cysticidal drugs modify the natural course of neurocysticercosis. PURPOSE: To perform a meta-analysis of randomized trials assessing the effect of cysticidal drugs on neuroimaging and clinical outcomes of patients with neurocysticercosis. DATA SOURCES: Search of MEDLINE, Cochrane Database of Systematic Reviews, and Literatura Latino-Americana y del Caribe en Ciencias de la Salud (LILACS) between 1979 and 2005. There were no language restrictions. STUDY SELECTION: Randomized trials of cysticidal drug therapy for neurocysticercosis that met predefined criteria designed to allow characterization of the disease and objective evaluation of therapy. The authors independently reviewed articles. Abstracted data included study design, number of randomly assigned patients and withdrawals, intervention, adverse events, timing of neuroimaging studies, and outcomes. DATA SYNTHESIS: Eleven studies met the inclusion criteria. Six trials randomly assigned 464 patients with cystic lesions (vesicular cysticerci), and 5 trials randomly assigned 478 patients with enhancing lesions (colloidal cysticerci). Parasites were located in the brain parenchyma or subarachnoid space at the convexity of the cerebral hemispheres. Cysticidal drug therapy was associated with complete resolution of cystic lesions (44% vs. 19%; P = 0.025). Trials on enhancing lesions showed a trend toward lesion resolution favoring the use of cysticidal drugs (72% vs. 63%; P = 0.38) that became statistically significant when an outlier trial was excluded from the analysis (69% vs. 55%; P = 0.006). Risk for seizure recurrence was lower after cysticidal treatment in patients with enhancing lesions (14% vs. 37%; P < 0.001). The single trial evaluating the frequency of seizures in patients with cystic lesions showed a 67% reduction in the rate of generalized seizures with treatment (P = 0.006). LIMITATIONS: Not all studies focused on the control of seizures as an outcome. CONCLUSIONS: Cysticidal drug therapy results in better resolution of colloidal and vesicular cysticerci, lower risk for recurrence of seizures in patients with colloidal cysticerci, and a reduction in the rate of generalized seizures in patients with vesicular cysticerci.

Bacterial Infections of the Central Nervous System.

PURPOSE OF REVIEW: Bacterial infections of the central nervous system are neurologic emergencies. Prompt recognition and treatment are essential not only to prevent mortality, but also to decrease neurologic sequelae. This article focuses on the two most common central nervous system bacterial infections, bacterial meningitis and spinal epidural abscess. RECENT FINDINGS: Two outbreaks of serogroup B meningococcal disease have occurred on US college campuses. The meningococcal vaccine given to young adults does not contain serogroup B. SUMMARY: In bacterial meningitis and in bacterial spinal epidural abscess, the identification of and eradication of the pathogen with antimicrobial therapy is the easy part. It is the recognition of the disorder, the understanding of which diagnostic studies to obtain and their limitations, and the management of the neurologic complications that require the expertise of a neurologist.

Encephalitis complicating smallpox vaccination.

A smallpox vaccination program has been initiated. The vaccine is a live virus that was used in the last century. Postvaccinal encephalitis is a complication of this vaccine. The clinical presentation, course, neuroimaging findings, and spinal fluid abnormalities are similar to a disorder that physicians are familiar with, acute disseminated encephalomyelitis. This complication can be prevented with the administration of antivaccinia gamma globulin at the time of vaccination. Antivaccinia gamma globulin is not efficacious once this complication occurs. Intravenous methylprednisolone is the recommended therapy, although intravenous immunoglobulin and plasmapheresis should be investigated in the treatment of postvaccinal encephalitis.

Antibacterial therapy of neurosyphilis: lack of impact of new therapies.

Neurosyphilis is caused by the spirochete Treponema pallidum. These organisms divide slowly, requiring long exposure to antibacterials for treatment success. In order for an antibacterial to be effective in the therapy of neurosyphilis, it must achieve treponemicidal concentrations in the CSF, have a long half-life and be given in a treatment regimen that favours compliance. Penicillin was first introduced for the treatment of syphilis in 1943, and despite interest in the use of amoxicillin, erythromycin, tetracycline, doxycycline, ceftriaxone and azithromycin, penicillin remains the only recommended antibacterial agent for neurosyphilis.