Diagnosis and treatment of encephalitis/meningitis

Abstract

Encephalitis and meningitis are severe neurological infections, and the neurologic manifestations of these conditions include fever, headache, altered mental status, convulsions, and psychiatric symptoms. It is critical that the clinician considers a broad range of causes, such as bacteria, virus, tuberculosis, fungus, and autoimmune or paraneoplastic diseases. Since treatment is more efficient if given early, these conditions of encephalitis/meningitis should represent as a life–threatening neurological emergency. For patients with suspected encephalitis/meningitis, therefore, empiric treatments should be initiated promptly based on the history, physical examination, and cerebrospinal fluid (CSF) findings. In this article, the author describes the characteristic clinical findings, magnetic resonance imaging and spinal fluid analysis of bacterial meningitis, tuberculous meningitis, cryptococcal meningitis, herpes simplex encephalitis, and anti–NMDA receptor encephalitis, and discusses the choice of empirical treatments until the cause of infection is determined. Also the differential diagnosis of encephalitis/meningitis is reviewed, with an emphasis on infectious etiologies.