From the Guidelines
The workup for pulsatile tinnitus should begin with a thorough history and physical examination, focusing on cardiovascular risk factors and neurological symptoms, as recommended by the American College of Radiology in their 2023 update 1. The initial evaluation should include a detailed otoscopic examination to help guide optimal imaging evaluation of pulsatile tinnitus. Initial imaging should include a contrast-enhanced CT angiography (CTA) or MR angiography (MRA) of the head and neck to evaluate vascular abnormalities, such as arterial lesions in the neck, intracranial etiologies, and venous causes like transverse sinus stenosis or sigmoid sinus diverticulum 1. Doppler ultrasonography of the neck vessels may be performed to assess for carotid stenosis or arteriovenous malformations. If initial imaging is inconclusive but clinical suspicion remains high, catheter angiography may be necessary as it provides superior vessel visualization. Audiometric testing should be included to evaluate hearing function and characterize the tinnitus. Laboratory tests should include complete blood count to rule out anemia, thyroid function tests, and lipid panel to assess cardiovascular risk factors, as pulsatile tinnitus can be caused by systemic factors such as pregnancy-related hemodynamic changes, anemia, or thyrotoxicosis 1. Depending on initial findings, additional specialized imaging such as temporal bone CT or cerebral venography might be indicated to evaluate for structural and anatomic causes of pulsatile tinnitus, such as superior semicircular canal dehiscence or sigmoid sinus wall abnormalities 1. This comprehensive approach is necessary because pulsatile tinnitus often indicates an underlying vascular abnormality, which may require specific treatment, and early diagnosis is important to prevent serious complications. The American Academy of Otolaryngology and Head and Neck Surgery Foundation guidelines also recommend a prompt and comprehensive audiological examination in patients with hearing problems or with unilateral persistent tinnitus 1. In patients with pulsatile tinnitus, it is essential to consider the possibility of underlying vascular abnormalities and to use a diagnostic algorithm based on a detailed history and clinical evaluation to progress from less invasive to more invasive imaging studies 1.
From the Research
Diagnostic Approach to Pulsatile Tinnitus
- Pulsatile tinnitus is a debilitating symptom that can be a harbinger of hemorrhagic or ischemic stroke, and careful diagnostic evaluation is critical in providing optimal care 2.
- A thorough evaluation can identify an underlying cause of pulsatile tinnitus in more than 70% of patients 2.
- The causes of pulsatile tinnitus can be categorized into structural, metabolic, and vascular groups, which facilitates a practical evaluation, referral, and treatment pattern 2.
Common Causes of Pulsatile Tinnitus
- Structural causes include neoplasms and temporal bone pathologic abnormalities 2.
- Metabolic causes include ototoxic medications and systemic causes of high cardiac output 2.
- Vascular causes include idiopathic intracranial hypertension and dural arteriovenous fistulas 2.
- Other causes include arteriopathies, venopathies, middle/inner ear pathology, and idiopathic causes 3.
Diagnostic Workup for Pulsatile Tinnitus
- A standard workup begins with a targeted history and physical examination to identify treatable causes and associated symptoms 4.
- A comprehensive audiologic evaluation should be performed for patients who experience unilateral tinnitus, tinnitus that has been present for six months or longer, or that is accompanied by hearing problems 4.
- Neuroimaging is not part of the standard workup unless the tinnitus is asymmetric or unilateral, pulsatile, associated with focal neurologic abnormalities, or associated with asymmetric hearing loss 4.
- Imaging studies such as magnetic resonance imaging with contrast, MR angiography, CT angiography, computed tomography without contrast, and MR Venogram may be ordered to identify the underlying cause of pulsatile tinnitus 3.
Evaluation and Management of Pulsatile Tinnitus
- Pulsatile tinnitus deserves a thorough evaluation, and in the majority of cases, there is a treatable underlying cause 5.
- The possibility of a life-threatening cause needs to be ruled out in every patient with pulsatile tinnitus 5.
- The otolaryngologist should be familiar with the evaluation and management of this symptom, and patients who lack a history of hypertension, obesity, vision changes, ipsilateral asymmetric hearing loss, or an abnormal otologic examination are less likely to have an identifiable cause for pulsatile tinnitus 3.