What are the causes of pulsatile tinnitus (a condition characterized by a rhythmic sound that synchronizes with the patient's heartbeat)?

From the Guidelines

Pulsatile tinnitus is primarily caused by abnormal blood flow in vessels near the ear, with common causes including vascular lesions, such as carotid atherosclerosis, dissection, fibromuscular dysplasia of the carotids, and intracranial etiologies like arteriovenous malformation (AVM), dAVF, and vascular tumors like glomus jugulare, as well as venous causes like transverse sinus stenosis and sigmoid sinus diverticulum 1. The causes of pulsatile tinnitus can be broadly categorized into vascular, venous, and structural/anatomic causes. Vascular causes include arterial lesions in the neck, such as carotid atherosclerosis, dissection, and fibromuscular dysplasia of the carotids, as well as intracranial etiologies like arteriovenous malformation (AVM), dAVF, and vascular tumors like glomus jugulare 1. Some key points to consider when evaluating pulsatile tinnitus include:

• Vascular causes: carotid atherosclerosis, dissection, fibromuscular dysplasia of the carotids, arteriovenous malformation (AVM), dAVF, and vascular tumors like glomus jugulare 1
• Venous causes: transverse sinus stenosis, sigmoid sinus diverticulum, persistent petrosquamosal sinus, and prominent mastoid or condylar emissary veins 1
• Structural/anatomic causes: superior semicircular canal dehiscence (SSCD), sigmoid sinus wall dehiscence, high jugular bulb, and Paget disease 1
• Systemic causes: pregnancy-related hemodynamic changes, anemia, thyrotoxicosis 1
• Mechanical causes: palatal or tympanic myoclonus, Eustachian tube contractions, or temporomandibular joint problems 1 Given the potential for serious underlying vascular conditions, diagnosis typically involves imaging studies like CT angiography, MRI, or ultrasound to visualize the blood vessels and identify the specific cause, allowing for appropriate treatment of the underlying condition 1.

From the Research

Causes of Pulsatile Tinnitus

• Vascular etiologies, including:
  • Neoplasm 2
  • Arteriovenous malformation or fistula 2
  • Idiopathic intracranial hypertension 2, 3
  • Dural venous sinus stenosis 2
  • Sigmoid sinus wall abnormalities (SSWAs) 3
  • Jugular vein anomalies (JVAs) 3
  • Emissary veins anomalies 3
• Non-vascular etiologies, including:
  • Otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) 2
  • Bony defects (e.g., superior semicircular canal dehiscence) 2
  • Transverse sinus stenosis (TSS) 3

Diagnostic Evaluation

• Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield 2
• Digital subtraction angiography (DSA) may further aid in the diagnosis if initial vascular imaging is negative and a vascular etiology is strongly suspected 2
• Magnetic resonance angiography/magnetic resonance venography and high-resolution temporal bone computed tomography can detect venous anomalies 3

Pathogenesis

• Turbulent blood flow as a result of luminal stenosis or abnormal dilation 3
• Amplification of internal sound due to temporal bone defects 3
• Abnormal position of the venous sinus system structures adjacent to the bony structures of the auditive apparatus 3