Acute mastoiditis: the role of imaging for identifying intracranial complications.

Objectives/Hypothesis: Brain CT is performed in patients presenting with acute mastoiditis (AM) to identify intracranial complications (ICC). Recently, however, the need for CT scans in such patients has been questioned owing to concerns regarding long-term effects of brain irradiation, with some clinicians claiming that the decision to scan should be based on a patient's clinical presentation. This study was aimed at characterizing the typical clinical presentation of patients who already have ICCs when diagnosed with AM, and to compare it to that of AM patients presenting without ICCs. Study Design: Prospective case series. Methods: All patients hospitalized with AM between July 1997 and December 2009 in an otologic tertiary referral center were divided into those with and those without ICCs on presentation. Prereferral clinical characteristics and the signs, symptoms, and inflammatory indexes at presentation were compared between the two groups. Results: Of 71 patients presenting with AM, 10 had at least one ICC (sigmoid sinus thrombosis [nine patients], perisinus empyema [five patients], subdural abscess [one patient], and epidural abscess [one patient]). Patients with and without ICCs did not differ regarding most clinical characteristics or presenting signs and symptoms. None presented with neurological signs or cranial nerve deficits. Conclusions: It is not possible to define an evidence-based index of suspicion for ICCs in patients with AM. Diagnostic imaging at presentation accordingly remains mandatory.