Christina C. Chang
Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne VIC
Introduction
People with HIV (PWH) presenting with central nervous system (CNS) manifestations require careful assessment as the differentials are broad. Key factors in the history and examination to narrow down the diagnostic possibilities include a sudden vs. insidious onset; an acute or vs. sub-acute vs chronic course; the presence or absence of associated features such as fevers, confusion, headache, memory loss, and localising neurological deficits; local epidemiology, and the degree of immunosuppression associated with HIV. OIs are more common with advanced HIV though malignancies such as primary CNS lymphoma or metastatic disease, and other non-infective conditions need to be considered. Most CNS OIs such as cryptococcal meningitis and meningoencephalitis, and the rarer OIs in our region, such as tuberculous meningitis (TBM), toxoplasmosis, and cytomegalovirus (CMV) encephalitis are associated with systemic infective symptoms. In contrast, the rare, progressive multifocal leucoencephalopthy (PML) typically has minimal infective features. Clearly, “common” CNS infections that occur in immunocompetent persons such as varicella zoster virus (VZV) encephalitis, enterovirus infections, and bacterial meningitis, can also occur in people with HIV (PWH). Dual pathology can also occur.
This chapter focuses on the two classical CNS OIs – cryptococcal meningitis and PML and is targeted at general practitioners and nurse practitioners working in Australasia. For detailed inpatient care, readers should consult definitive texts and guidelines, including the various guidelines for cryptococcosis (Global guidelines published by the European Congress of Medical Mycology (ECMM) (1), HIV-guidelines by the US Center for disease control (CDC) (2), HIV guidelines by European AIDS EACS (3), Australasian haematology-Oncology antifungal guidelines(4)). For PML and other OIs, please refer to the HIV-guidelines by the US CDC (2).