Subacute measles encephalitis with AIDS diagnosed by fine needle aspiration biopsy. A case report.

Background: Subacute measles encephalitis (SME), or measles inclusion body encephalitis (MIBE), is a rare central nervous system (CNS) complication following infection by the measles (rubeola) virus. It usually occurs in young patients with defective cellular immunity from either congenital or acquired causes. In the United States, with the resurgence of measles infection and the human immunodeficiency virus (HIV) pandemic, subacute measles encephalitis should be added to the differential diagnosis in acquired immune deficiency syndrome (AIDS) patients presenting with unexplained CNS manifestations.

Case: A 2-year-old, HIV-positive, white male was admitted for generalized convulsive seizures. Vaccination was described as "up to date." Despite treatment with anticonvulsive drugs, the child continued to develop frequent partial and generalized seizures. Cephalic computed tomography and magnetic resonance imaging revealed a hypodense area in the right parietotemporal cortex without an associated mass effect. Fine needle aspiration biopsy (FNAB) of the affected area showed neuronal reduction, degeneration with eosinophilic intranuclear inclusions, perivascular lymphoplasmacytic infiltration and gliosis. Electron microscopy of the intranuclear inclusions revealed fine, fibrillar, tubular nucleocapsids, consistent with the measles virus.

Conclusion: Acute measles encephalitis (AME), subacute sclerosing panencephalitis (SSPE), and SME are the three CNS syndromes associated with measles infection. Serum and cerebrospinal fluid (CSF) antibody titres against measles virus are usually high and helpful in the diagnosis of AME and SSPE. In SME, neither serum nor CSF antibody titres against measles are high. Therefore, FNAB is necessary for a definitive diagnosis.