The brain is a monstrous, beautiful mess.
William F. Allman (from Apprentices of Wonder. Inside the Neural Network Revolution, 1989) .
Neurologic infections often are a cause of both anguish and fascination for many clinicians. Acute bacterial meningitis is a medical emergency, like acute stroke or myocardial infarction, if not treated early can rapidly deteriorate. A 3-h delay in treatment for pneumococcal meningitis can increase mortality by about 14 times . On the contrary, chronic encephalitis and meningitis can linger like smoldering embers, evading a diagnosis, testing a clinician's acumen and perseverance. The discovery of immune-medicated encephalitis and novel molecular diagnostics for pathogen detection have certainly improved our diagnostic ability to find a cause, but even today a significant number of cases remain undiagnosed. In most published series, around 40% or more cases do not have an etiologic diagnosis [3–5]. I think it is accurate to say that the vast ocean of neurological infections and inflammatory diseases is uncharted and yet to be discovered, but this is an exciting time we live in as we are making great discoveries and progress. In this series, we explore neurological infection syndromes, especially areas where there have been recent advances or new conceptual ways of approaching them clinically.
The article update on community acquired bacterial meningitis reviews the changing epidemiology, diagnostic testing including Cerebrospinal Fluid (CSF) multiplex PCRs, the role of computer tomography brain and management. (pp. 233–238)
The article update on Herpes Simplex Virus (HSV) encephalitis explores diagnosis and management, and especially newer studies on epidemiology and pathogenesis, which have implications on therapeutic targets to modulate immune response to HSV. (pp. 239–243)
The article on advances in molecular testing for CNS infections reviews diagnostic yield and accuracy for pathogen detection of different tests. It also explores newer diagnostic tools like unbiased metagenomic testing, that have the potential of detecting novel pathogens and known pathogens with atypical clinical presentations. (pp. 244–250)
The article on immune-mediated encephalitis explores this emerging field, epidemiology of autoimmune encephalitis, how to distinguish it from infectious encephalitis, diagnostic testing and treatment relevant to an infectious disease clinician. (pp. 251–258)
The article on lyme neuroborreliosis reviews, analyzes and synthesizes a complex and controversial topic with useful practical clinical tips, including information on newer tests. (pp. 259–264)
The article on spinal epidural abscess reviews risk factors, radiologic characteristics especially on MRI that are important for a clinician, and newer trends in conservative management with predictive models for failure of response to treatment. (pp. 265–271)
The chapter on human prion diseases reviews the epidemiology, pathology and diagnostic testing including newer tests like CSF RT-QuIC. (pp. 272–276)
The update on fungal infections of the CNS reviews the burden of such infections, various causes and their risks. It also explores management and the utility of diagnostic tests like antigen-based tests and molecular tests. (pp. 277–284)
Infectious causes of stroke are rare, but often misdiagnosed or diagnosed late with devastating consequences. The article on this topic explores associations of infections with stroke and also diagnosis and treatment of infectious causes like Varicella Zoster Virus (VZV) vasculopathy, tuberculous and fungal causes of stroke. (pp. 285–292)
This compilation of articles is more of a field guide, than an encyclopedia, and we sincerely hope it is useful for the busy clinician.
I would like to thank the authors of the articles in this series for the contribution.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
2. Auburtin M, Wolff M, Charpentier J, et al. Detrimental role of delayed antibiotic administration and penicillin-nonsusceptible strains in adult intensive care unit patients with pneumococcal meningitis: the PNEUMOREA prospective multicenter study. Crit Care Med 2006; 34:2758–2765.
3. Bloch KC, Glaser CA. Encephalitis surveillance through the emerging infections program, 1997-2010. Emerg Infect Dis 2015; 21:1562–1567.
4. Mailles A, Stahl JP. Steering Committee and Investigators Group. Infectious encephalitis in France in 2007: a national prospective study. Clin Infect Dis 2009; 49:1838–1847.
5. Granerod J, Ambrose HE, Davies NW, et al. Causes of encephalitis and differences in their clinical presentations in England: a multicenter, population-based prospective study. Lancet Infect Dis 2010; 10:835–844.