Bacterial Infections of the Central Nervous System Roos, Karen L. MD, FAAN Abstract Bacterial infections of the central nervous system are a neurological emergency. Prompt recognition and treatment are not only essential to prevent mortality but also to decrease neurological sequelae. This chapter will focus on the two most common central nervous system bacterial infections, bacterial meningitis and spinal epidural abscess. The eradication of the pathogen with antimicrobial therapy is the easy part. It is the recognition of the disorder, the understanding of the diagnostic studies and their limitations, and the management of the neurological complications that requires the expertise of a neurologist. Introduction There are a number of bacterial infections of the central nervous system, including meningitis, brain abscess, cranial and spinal epidural abscess and subdural empyema and suppurative dural sinus thrombophlebitis, but this chapter will focus on the two central nervous system bacterial infections that neurologists encounter the most often and have a critical role in diagnosis, management and lifetime care. Those infections are bacterial meningitis and spinal epidural abscess. Meningitis For two centuries, the clinical presentation of bacterial meningitis was recognized as the classic triad of fever, headache and stiff neck. Then a number of years ago, papers began to appear in the literature challenging the classic triad, primarily over the lack of, or ability to detect, a stiff neck. This controversy was resolved by the recognition that the majority of patients with bacterial meningitis have fever (greater than or equal to 38.5° C), and either headache, stiff neck or an altered level of consciousness. 1‐3 A symptom that is often present, but under recognized as a symptom of central nervous system (CNS) infection, is vomiting. When bacterial meningitis is considered a possibility, blood cultures should be obtained and empiric antimicrobial and adjunctive therapy initiated. Empiric antimicrobial therapy is based on predisposing and associated conditions which predict the meningeal pathogen. Almost all recommended empiric antimicrobial regimens include a third‐or fourth generation cephalosporin plus vancomycin. Ampicillin is added for coverage of Listeria monocytogenes where indicated (discussed below), and metronidazole when the predisposing conditions of otitis, sinusitis or mastoiditis are present. 4 Prior to or with the first dose of antibiotic therapy, dexamethasone (0.15 mg/kg every six hours for 2‐4 days) is initiated in patients with suspected pneumococcal, meningococcal or Haemophilus influenzae type b meningitis. 5‐7 Empiric therapy based on the _________________________________________________________________________________ This is the author's manuscript of the article published in final edited form as: Roos, K. L. (2015). Bacterial Infections of the Central Nervous System. CONTINUUM: Lifelong Learning in Neurology, 21, 1679–1691. http://doi.org/10.1212/CON.0000000000000242