This chapter provides a practical guide for clinicians evaluating patients with suspected central nervous system (CNS) infections. Emphasis is placed on common presentations, differential diagnosis, confirmatory testing, initial treatment options, and monitoring response to therapy. Acute bacterial meningitis is characterized by headache, fever, and neck stiffness. Nausea, vomiting, photophobia and seizures are common. Aseptic meningitis is a nonspecific term applied historically to patients with meningitis and negative blood and cerebrospinal cultures. Encephalitis involves brain parenchyma; fever and altered mentation are the predominant presenting symptoms. Brain abscesses are space-occupying CNS lesions which, depending on size and location, may cause focal neurological deficits. Epidural abscess is a neurological emergency. Neurological complications of HIV infection are common and have evolved with introduction of newer therapies. Patients are now living longer with HIV, and CNS pathogens have largely been replaced by HIV-associated cognitive impairment and peripheral neuropathy.

This chapter discusses the burden and the changing epidemiology of acute bacterial meningitis (ABM) and the incidence of epilepsy following ABM and intracranial abscesses in children. It identifies the predictive factors, therapeutic implications, and prevention of ABM and consequent epilepsy in these conditions. Of the acquired causes, central nervous system (CNS) infections are common in childhood and include bacterial meningitis, viral encephalitis, and intracranial suppurative infections such as brain abscess, subdural empyema, and cranial epidural abscess. The changing epidemiology of bacterial meningitis and the emergence of antibiotic resistant strains of pneumococcal meningitis demand regional guidelines for initial empirical treatment of ABM based on the knowledge of regional epidemiologic factors. The effectiveness of administration of dexamethasone before the first effective parenteral antibiotic dose in reducing neurologic and/or audiologic sequelae in children with Haemophilus influenzae type B (HiB) meningitis has been demonstrated in several studies.