“I’ve got a bad headache”

The incidence of nearly all AIDS-defining opportunist infections (OIs) decreased significantly in the era after antiretroviral therapy (ART). Those OIs that occur do so at low CD4+ T-cell counts, primarily in persons living with HIV (PLWH) with delayed diagnosis who have either not initiated ART or have been nonadherent to both ART and OI prophylaxis. The most profound effect on survival of patients living with AIDS is conferred by ART, but specific OI prevention measures are all associated with a survival benefit. For most PLWH with an acute OI, ART should be considered within the first 2 weeks of treatment for the acute OI. However, in treatment-naïve PLWH with cryptococcal meningitis or tuberculosis (TB), it has been shown that there is increased mortality and morbidity in industrialized countries with early initiation of ART due to immune reconstitution inflammatory syndrome complications. Prophylaxis against many OIs can be discontinued for patients who respond to ART and maintain CD4+ cells above the recommended threshold for more than 3 months. This chapter presents cases of the most common opportunistic central nervous system infections in PLWH.