Petrous Carotid Aneurysm Causing Pulsatile Tinnitus: Case Report and Review of the Literature

Causes of Pulsatile Tinnitus and Treatment Options

Pulsatile tinnitus (PT) requires detailed workup to evaluate for an underlying structural cause. With advances in neuroimaging, structural venous abnormalities that can cause PT have becoming increasingly recognized. A number of anomalies, including dural arteriovenous fistulas, idiopathic intracranial hypertension, transverse sinus stenosis, sigmoid sinus wall abnormalities, jugular venous anomalies, and hypertrophied emissary veins, have been implicated in flow disruption and turbulence in the vicinity of auditory structures, resulting in PT. Endovascular treatment options, including stenting, coiling, and embolization with liquid agents, have demonstrated high efficacy and safety. These treatments can lead to symptomatic relief in carefully selected cases.

Pulsatile Tinnitus: Differential Diagnosis and Approach to Management

PURPOSE OF REVIEW

The purpose of this review is to provide an updated approach to the evaluation and management of pulsatile tinnitus (PT), an uncommon but often treatable subtype of tinnitus.

RECENT FINDINGS

Secondary PT can be due to either vascular or non-vascular etiologies, including, but not limited to: neoplasm, arteriovenous malformation or fistula, idiopathic intracranial hypertension, dural venous sinus stenosis, otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) and bony defects (e.g., superior semicircular canal dehiscence). Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield, though each may be more sensitive to specific etiologies. If initial vascular imaging is negative and a vascular etiology is strongly suspected, digital subtraction angiography (DSA) may further aid in the diagnosis. Many vascular etiologies of PT can be managed endovascularly, often leading to PT improvement or resolution. Notably, venous sinus stenting is an emerging therapy for PT secondary to idiopathic intracranial hypertension with venous sinus stenosis. Careful history and physical exam can help establish the differential diagnosis for PT and guide subsequent evaluation and management. Additional studies on the efficacy and long-term outcome of venous sinus stenting for venous stenosis are warranted.

Anatomical Variations of the Jugular Foramen Region in Patients with Pulsatile Tinnitus

Objective  Structural anomalies of the jugular foramen (JF) and adjacent structures may contribute to development of pulsatile tinnitus (PT). The goal of this study was to assess anatomical variants in the ipsilateral JF region in patients with PT and to explore possible predisposing factors for PT. Methods  One hundred ninety-five patients with PT who underwent CT angiography and venography of the temporal bone were retrospectively analyzed. Anatomic variants including dominance of the ipsilateral JF, bony deficiency of the sigmoid sinus and internal carotid artery canal, high riding or dehiscent jugular bulb, dehiscence of the superior semicircular canal, tumors in the JF region, or cerebellopontine angle were assessed. Results  Of 195 patients with PT, the prevalence of a dominant JF on the ipsilateral side of patients with PT was 67.2%. Furthermore, the dominant JF demonstrated a significant correlation with the presence of ipsilateral PT ( p  < 0.001). No anatomical variants were present in 22 patients (11.3%), whereas in patients with structural variants, bony deficiency of the sigmoid sinus was most common (65.6%), followed by high riding (54.9%) or dehiscent jugular bulb (14.4%). Dehiscent internal carotid artery canal (3.1%) and superior semicircular canal (4.1%) were occasionally identified, while arteriovenous fistula, arterial aneurysm and tumors arising from the JF region or cerebellopontine angle were rarely encountered. Conclusion  Structural abnormalities of the JF and adjacent structures may predispose to the development of PT. Knowledge of these anatomical variants in the JF region may help establish a clinical strategy for addressing PT.

Neurosurgical Causes of Pulsatile Tinnitus: Contemporary Update

Traditionally in the domain of the otolaryngologist, pulsatile tinnitus (PT) has become increasingly relevant to neurosurgeons. PT may prove to be a harbinger of life-threatening pathology; however, often, it is a marker of a more benign process. Irrespectively, the neurosurgeon should be familiar with the many potential etiologies of this unique and challenging patient population. In this review, we discuss the myriad causes of PT, categorized by pulse-phase rhythmicity.