28 Clinical Features and Outcomes of Objective Pulsatile Tinnitus

Abstract Introduction Pulsatile tinnitus can be subjective or objective (OPT), with significant delay to diagnosis OPT aetiology is poorly characterised, and very little is known about the risk of serious pathology for patients with OPT, with diagnoses such as dural arteriovenous fistula (dAVF) having potentially life-threatening intracranial abnormalities. Methods All patients with OPT at Addenbrooke’s, Cambridge, were prospectively studied between December 2004-March 2022 (n=59). We collected information on history, auscultation, IJV compression, myofascial triggers, otoscopy, pure tone audiometry, and CT arteriography and venography findings with concurrent Borden and Cognard classification. Results OPT has a very high chance of radiological somatic diagnosis (89.8%), with a high proportion of dAVFs (45.8%, n=27), and importantly, 16.7% of dAVFs were classified as Borden and Cognard Type 3 or above, indicating increased risk of intracranial haemorrhage, neurological deficit, or death. Mean age of OPT onset was 49.0±16.9, being significantly higher in patients with dAVF (58.9±9.5) or arterial abnormality (56.8±14.7) compared to idiopathic intracranial hypertension or venous origin (p<0.001). dAVFs also had a more equal gender split compared to female-predominant arterial, IIH and venous OPT (p=0.006). The significant QoL impact caused by dAVF-induced OPT is frequently treatable, typically by embolisation±styloidectomy, with 19 cases showing resolution/improvement. Conclusions OPT must always undergo a thorough work-up for somatic causes given the high likelihood of diagnosis and critical risk of mortality and serious neurological complications if dAVFs causing OPT are missed. Treatment is often successful and should be undertaken at an appropriate centre of expertise.