Acute encephalopathy, streptococcal infection, and cryoglobulinemia.

A 9-year-old girl had an acute encephalopathic illness characterized by disordered consciousness, seizures, and multiple cortical deficits. The acute illness was associated with serologic evidence of an antecedent streptococcal infection and the presence of a mixed cryoglobulin with specific antistreptococcal antibody activity. Although the patient had no other evidence of a systemic or central nervous system vasculitis, computerized tomography demonstrated changes compatible with a vasculitic process. Treatment with corticosteroids was associated with resolution of the cryoglobulinemia and complete clinical recovery.