CURRENT Essentials of Critical Care.pdf

Chapter 10 Infectious Disease 135Central Nervous System (CNS) Infectionsin HIV-Infected Patients■ Essentials of Diagnosis• Cryptococcal meningitis: headache and/or fever dominant findings,India ink test on CSF—sensitivity 70%; CSF cryptococcalantigen 95% sensitive; CSF culture 98% sensitive• Toxoplasmosis: focal neurologic deficits common; CT scan: 2ring-enhancing lesions involving basal ganglia; serum toxoplasmaantibody in 95%; primary CNS lymphoma usually singlelarge lesion in deep periventricular space with variable enhancement• PML: cognitive deficits common; multiple hypodense lesions inwhite matter on MRI, usually without edema or enhancement;JC virus CSF PCR 80% sensitive; distinguish from HIV dementiaand encephalopathy■ Differential Diagnosis• Noninfectious HIV-associated neurologic disorders: HIV dementiaand encephalopathy, primary CNS lymphoma• Stroke• Primary or metastatic brain tumor■ Treatment• CNS toxoplasmosis: sulfadiazine plus pyrimethamine and leucovorin;empiric therapy for suspected cases pending results ofserum toxoplasma antibody; reevaluate clinical and radiographicresponse (MRI or CT) in 7–10 days• Cryptococcal meningitis: Amphotericin B 5-flucytosine followedby fluconazole• Secondary prophylaxis indicated for toxoplasmosis and cryptococcalmeningitis• PML and HIV dementia: no specific therapy available; antiretroviraltherapy associated with improved outcome• Consider optimal timing of antiretroviral therapy to avoidimmune reconstitution syndrome (toxoplasmosis, tuberculousmeningitis, PML)■ PearlMeningismus is rare in cryptococcal meningitis, and CSF profile maybe completely normal.ReferenceAmmassari A: Diagnosis of AIDS-related focal brain lesions: a decision-makinganalysis based on clinical and neuroradiologic characteristics combinedwith polymerase chain reaction assays in CSF. Neurology 1997;48:687.[PMID: 9065549]