RESUMO
The frequency of mastoiditis and its complications have declined since the advent of antibiotics. Among all complications, transverse sinus thrombosis is the least frequent, although it may have the highest mortality rate. Before the introduction of surgery and antibiotic treatment, mortality was close to 100%. Previous administration of antibiotics may lead to changes in the clinical presentation of venous sinus thrombosis that make diagnosis more difficult, in spite of greatly improved imaging methods. This article reports 4 confirmed cases of venous sinus thrombosis complicating mastoiditis that were diagnosed and treated at Nossa Senhora das Graças Hospital, Curitiba--PR from June, 1999, to February, 2000. All 4 cases were documented by magnetic resonance imaging. Each patient recovered after treatment with antibiotics and anticoagulation. No surgical intervention was necessary. Diagnosis of the complication requires a high level of clinical suspicion and then evaluation by mastoid CT and cranial MRI.