Central Nervous System Infections in Patients Receiving Cancer Therapies

Abstract

Despite evidence-based prophylactic regimens, advanced pathogen detection technologies, and organism-specific antimicrobial agents, central nervous system (CNS) infections continue to cause significant morbidity and mortality in patients receiving cancer therapies. More intense immunosuppression coupled with longer survival has changed the spectrum, pattern and timing of infections in several vulnerable populations. Patients at highest risk for CNS infection are hematopoietic cell transplant recipients and neurosurgical patients. The clinical presentation and radiographic appearance of infections in such patients may differ from those occurring in other populations, including HIVAIDS patients. Major deficits predisposing cancer patients to infection include neutropenia, barrier disruption, B-lymphocyte or immunoglobulin deficiency, and impaired T-lymphocyte-mediated immunity. Potential non-infectious mimics of CNS infection include posterior reversible encephalopathy syndrome (PRES), immune reconstitution inflammatory syndrome (IRIS), drug toxicity, and para-infectious antibody-mediated inflammatory syndromes. This chapter provides a practical clinical approach to potential CNS infections in patients receiving cancer therapies based on the most commonly affected patient groups, neuroanatomic site of disease, and laboratory tests. Clinical descriptions and general management recommendations are offered for bacterial infections, invasive fungal infections, and opportunistic viral infections including progressive multifocal leukoencephalopathy.