Type I cerebral dural arteriovenous fistulas of the lateral sinus: clinical features in 24 patients.

To review the clinical and diagnostic characteristics of type I cerebral dural arteriovenous fistulas (CDAVF) of the lateral sinus medical records of 24 patients with Type I CDAVF were retrospectively reviewed. All patients were interviewed aiming at presenting symptoms, impact on daily functioning, diagnostic delay, relevant medical history and post-treatment status. Nineteen of 24 patients (79%) were women. The median age at the time of diagnosis was 56 years (range 32-69). Unilateral pulsatile tinnitus was the presenting symptom in all patients. A bruit could be heard at auscultation on the retroauricular skull in all patients. The median diagnostic delay was 17.9 months (range 1-120). Standardized magnetic resonance imaging (MRI) of the brain was normal in all patients. The diagnosis of CDAVF was confirmed on cerebral angiography. In conclusion, CDAVF type I of the lateral sinus occurs predominantly in middle aged women and presents with unilateral pulsatile tinnitus, which resulted in impairment of social and occupational functioning in the vast majority of patients. An audible bruit at retroauricular auscultation confirms the clinical diagnosis of a cerebral dural fistula. MRI is not helpful in the diagnosis and cerebral angiography is indicated to classify the dural fistula.