MRI and MR angiography evaluation of pulsatile tinnitus: A focused, physiology-based protocol

ESR Essentials: diagnostic strategies in tinnitus-practice recommendations by the European Society of Head and Neck Radiology

Tinnitus is common, with approximately 1/4 of the elderly population experiencing chronic tinnitus. While non-pulsatile tinnitus usually has no structural cause, pulsatile tinnitus is more likely to have an identifiable aetiology, and imaging plays a key role in the search for treatable and life-threatening causes. Since the characteristics of the tinnitus guide the diagnostic strategy, a detailed clinical assessment should always be performed before imaging is considered. In the setting of non-pulsatile tinnitus, imaging with MRI should only be performed if it is unilateral or asymmetric, or when it is associated with focal neurologic abnormalities or asymmetric hearing loss. In contrast, imaging investigation is always required in the presence of pulsatile tinnitus. Whilst there are specific clinical features in which temporal bone CT will be the initial imaging strategy for pulsatile tinnitus (e.g., retrotympanic mass or conductive hearing loss), most patients will require either CT or MRI with arterial and venous imaging. The clinical categorisation of pulsatile tinnitus as "arterial" or "venous" may guide the radiological search and help understand the significance of certain imaging findings (e.g., venous variants). Significant pathology (e.g., dural arteriovenous malformation) must be excluded in the context of objective pulsatile tinnitus and may require additional cross-sectional imaging; conventional angiography is now rarely indicated. KEY POINTS: In patients with unilateral, non-pulsatile tinnitus, MRI should be performed to rule out retrocochlear disease. All patients with pulsatile tinnitus should be imaged and the clinical assessment guides the selection of the most appropriate imaging technique. If the first imaging study does not reveal the suspected cause of objective pulsatile tinnitus, additional imaging investigations should be performed to exclude alternative diagnoses.

Non-invasive imaging modalities for diagnosing pulsatile tinnitus: a comprehensive review and recommended imaging algorithm

Pulsatile tinnitus (PT) is a challenging diagnostic condition arising from various vascular, neoplastic, and systemic disorders. Non-invasive imaging is essential for identifying underlying causes while minimizing risks of invasive diagnostic angiography. Although no consensus exists on the primary imaging modality for PT and currently CT, ultrasound, and MRI are used in the diagnostic pathway, MRI is increasingly preferred as the first-line screening test for its diagnostic efficacy and safety. MRI protocols such as time-of-flight, magnetic resonance angiography, diffusion-weighted imaging, and arterial spin labeling can identify serious causes, including vascular shunting lesions, venous sinus stenosis, and tumors. In this narrative review of the current literature we discuss the benefits and limitations of various non-invasive imaging modalities in identifying the characteristic imaging findings of the most common causes of PT and also provide an algorithm that clinicians can use to guide the imaging evaluation.

Imaging of Pulsatile Tinnitus

Tinnitus is a common complaint that approximately three-fourths of adults will experience at some point in their life. While for many it is a mild nuisance, for some it can be debilitating, affecting cognition and quality of life, increasing stress, and leading to anxiety, depression, and in severe circumstances even suicide. Pulsatile tinnitus refers to the perception of a heartbeat-like sound without external stimulus. Although less common than nonpulsatile tinnitus, pulsatile tinnitus raises concern for underlying disease that can have a high risk of causing the patient harm if undiagnosed, and most of these patients will have positive findings at imaging. While these findings are often subtle, identifying them can have a meaningful impact on the patient's quality of life. The literature on pulsatile tinnitus is changing rapidly with improved imaging techniques and novel minimally invasive treatment options. A careful history and physical examination together with appropriate imaging are therefore critical in identifying the underlying cause. With emerging surgical, endovascular, and supportive technologies, the vast majority of patients with bothersome pulsatile tinnitus can be cured or have their symptoms ameliorated. The objective of this narrative review is to present a comprehensive analysis of the currently available literature on pulsatile tinnitus, with a focus on understanding its pathophysiologic mechanisms, diagnostic pathways, imaging findings, and the spectrum of available management strategies and ultimately to propose a structured framework that aids radiologists as well as clinicians in identifying an underlying diagnosis and guiding management of these patients. ©RSNA, 2024 Supplemental material is available for this article.

Beyond the Buzz: Cortical and subcortical brain changes in patients with pulsatile tinnitus

Pulsatile tinnitus (PT) can be a debilitating condition characterized by rhythmic, heartbeat-synchronous sounds, which can severely impact patients' quality of life. Understanding the neuroanatomical changes in PT patients may provide critical insights into the impacts of this condition. This study aimed to investigate potential differences in cortical and subcortical brain volume between adults with PT and age-matched controls (60 to 70 years of age). A retrospective, cross-sectional analysis of imaging and medical records was conducted, with data collected from January 2015 to December 2021. The study was conducted in a tertiary referral center with a specialized tinnitus clinic. A total of 135 adults diagnosed with PT and 135 age-matched controls were included. All participants were screened for PT and relevant medical history, with consecutive sampling used for selection. Cortical and subcortical brain volume differences between PT patients and controls were measured using Freesurfer. PT patients (n = 79, after exclusion of patients with inadequate imaging data) exhibited significant decreases in cortical thickness in the anterior cingulate and entorhinal cortex, and decreased volume in the left putamen, compared to age-matched controls (n = 135). PT patients also demonstrated significant increased volume in frontal and occipital lobe structures, the cerebellum, hippocampi, and ventral pallidum. In conclusion, our findings suggest that individuals with PT may have structural differences in brain regions related to auditory processing, and depression, which provides additional evidence of the psychiatric sequalae of PT. These findings demonstrate that there are neuroanatomical alterations in patients with PT, emphasizing the value in evaluating and treating this disease to prevent these neuroanatomical differences from developing.

Noninvasive Treatment of Venous Pulsatile Tinnitus with an Internal Jugular Vein Compression Collar

OBJECTIVE

The study was conducted to evaluate the safety and efficacy of mild internal jugular (IJV) compression via an FDA approved compression collar for symptomatic treatment of venous pulsatile tinnitus.

METHODS

This is a prospective study that recruited 20 adult patients with venous pulsatile tinnitus. Participants completed the Tinnitus Handicap Inventory (THI), were fitted with the collar, and rated symptom intensity on a 10-point tinnitus intensity scale before and during collar use. Once weekly for 4 weeks, they answered a survey quantifying days used, average tinnitus intensity before and after wearing the collar each day of use, and any safety concerns. Lastly, they completed an exit interview. The primary outcome was symptomatic relief, with secondary outcomes of safety, effect of treatment setting, effect of time, and quality of life assessed via nonparametric testing.

RESULTS

18 participants completed the study, and 276 paired daily before use/during use intensity scores were submitted. The median symptom intensity without the collar was 6 (IQR 4, 7), whereas with the collar it was 3 (IQR 2, 5), for a median symptomatic relief of 50%. The collar had a significant effect in reducing symptom intensity (p < 0.0001) and burden of illness via the THI (p < 0.0001). There was no effect of setting, frequency, or time on symptomatic relief with the collar. There were no adverse safety events reported aside from minor discomfort upon initial application.

CONCLUSIONS

Venous compression collars offer acute symptom relief for patients with venous pulsatile tinnitus. Further study is needed to assess safety and efficacy of longitudinal use.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3342-3348, 2024.

Clinical evaluation of pulsatile tinnitus: history and physical examination techniques to predict vascular etiology

BACKGROUND

Pulsatile tinnitus (PT) may be due to a spectrum of cerebrovascular etiologies, ranging from benign venous turbulence to life threatening dural arteriovenous fistulas. A focused clinical history and physical examination provide clues to the ultimate diagnosis; however, the predictive accuracy of these features in determining PT etiology remains uncertain.

METHODS

Patients with clinical PT evaluation and DSA were included. The final etiology of PT after DSA was categorized as shunting, venous, arterial, or non-vascular. Clinical variables were compared between etiologies using multivariate logistic regression, and performance at predicting PT etiology was determined by area under the receiver operating curve (AUROC).

RESULTS

164 patients were included. On multivariate analysis, patient reported high pitch PT (relative risk (RR) 33.81; 95% CI 3.81 to 882.80) compared with exclusively low pitch PT and presence of a bruit on physical examination (9.95; 2.04 to 62.08; P=0.007) were associated with shunting PT. Hearing loss was associated with a lower risk of shunting PT (0.16; 0.03 to 0.79; P=0.029). Alleviation of PT with ipsilateral lateral neck pressure was associated with a higher risk of venous PT (5.24; 1.62 to 21.01; P=0.010). An AUROC of 0.882 was achieved for predicting the presence or absence of a shunt and 0.751 for venous PT.

CONCLUSION

In patients with PT, clinical history and physical examination can achieve high performance at detecting a shunting lesion. Potentially treatable venous etiologies may also be suggested by relief with neck compression.

Cerebrovascular pulsatile tinnitus: causes, treatments, and outcomes in 164 patients with neuroangiographic correlation

BACKGROUND

Pulsatile tinnitus (PT) can cause significant detriment to quality of life and may herald a life-threatening condition. Endovascular evaluation is the gold standard for the definitive diagnosis of PT and facilitates treatment. However, no large study has determined the distribution of causes and treatment outcomes of PT evaluated endovascularly.

METHODS

Consecutive patients evaluated at a multidisciplinary PT clinic from a single academic center were retrospectively reviewed. Patients with a suspected cerebrovascular etiology of PT based on clinical and/or non-invasive imaging, who were evaluated by endovascular techniques (arteriography, venography, manometry, and/or balloon test occlusion), were included in analysis. Baseline clinical features and treatment results by final etiology of PT were compared.

RESULTS

Of 552 patients referred for PT evaluation, 164 patients (29.7%) who underwent endovascular evaluation of PT were included. Mean (±SD) age at first clinical evaluation was 54.3±14.1 years (range 25-89 years); 111 patients (67.7%) were female. PT causes were 75.6% vascular and 24.4% non-vascular. Arteriovenous shunting lesions caused 20.7% of cases, venous etiologies 48.2%, and arterial etiologies 6.7%. Of patients with a shunting lesion treated with endovascular embolization, 96.9% had lasting significant improvement or resolution in PT. Endovascular stenting for venous sinus stenosis gave 84.6% of patients lasting improvement or resolution in PT. Arterial and non-vascular PT had fewer patients treated endovascularly and less improvement in PT symptoms.

CONCLUSION

PT with a suspected vascular cause is most often attributable to venous etiologies. PT caused by arteriovenous shunting or venous sinus stenosis may be effectively treated endovascularly.

Intracranial pressure, lateral sinus patency, and jugular ultrasound hemodynamics in patients with venous pulsatile tinnitus

The clinical and hemodynamic characteristics of venous pulsatile tinnitus (PT) patients with normal or elevated cerebrospinal fluid pressure (CSFP) have not been clearly differentiated. This study aimed to explore CSFP among patients with PT as the solitary symptom, as well as quantitatively and qualitatively assess the role of the degree of transverse sinus (TS) stenosis and jugular hemodynamics in venous PT patients. A total of 50 subjects with venous PT with or without sigmoid sinus wall anomalies (SSWAs) were enrolled in this study. In addition to radiologic assessments for TS stenosis and invagination of arachnoid granulation (AG) in TS, CSFP and jugular hemodynamics were measured via cerebrospinal fluid (CSF) manometry and Doppler ultrasound. Apart from group comparisons and correlation analyses, multivariate linear regression, and receiver operating characteristic (ROC) models were used to identify the sensitivity and specificity of the index of transverse sinus stenosis (ITSS) and hemodynamic variables with inferential significance. The mean CSFP of all cases was 199.5 ± 52.7 mmH2O, with no statistical difference in CSFP between the diverticulum and dehiscence groups. Multivariate linear regression analysis demonstrated that CSFP was linearly correlated with ITSS and pulsatility index (PI). ROC analysis showed that the area under the ROC curve of PI was 0.693 at 200 mmH2O threshold, and the best PI cut-off value was 0.467, with a sensitivity of 65.7% and specificity of 81.8%. For 250 mmH2O threshold, the area under the ROC curve of PI was 0.718, and the best PI cut-off value was 0.467 with a sensitivity of 68.4% and specificity of 75.0%. Additionally, the area under the ROC curve of ITSS was 0.757, and the best ITSS cutoff value was 8.5 (p = 0.002, 95% CI = 0.616–0.898) with a sensitivity of 72.4% and specificity of 75.0% at 200 mmH2O threshold. In conclusion, patients with venous PT as the only presenting symptom should be suspected of having borderline or increased CSFP when they present with high ITSS, BMI and low PI. Further, AG in TS without encephalocele and empty sellae are not limiting findings for differentiating the level of CSFP in patients with venous PT.

Retroauricular/Transcranial Color-Coded Doppler Ultrasound Approach in Junction With Ipsilateral Neck Compression on Real-Time Hydroacoustic Variation of Venous Pulsatile Tinnitus

Alterations in dural venous sinus hemodynamics have recently been suggested as the major contributing factors in venous pulsatile tinnitus (PT). Nevertheless, little is known about the association between real-time alterations in hemodynamics and the subjective perception of venous PT. This study aimed to investigate the hydroacoustic correlations among diverticular vortices, mainstream sinus flow, and PT using various Doppler ultrasound techniques. Nineteen venous PT patients with protrusive diverticulum were recruited. The mainstream sinus and diverticular hemodynamics before and after ipsilateral internal jugular vein (IJV) compression were investigated using an innovative retroauricular color-coded Doppler (RCCD) method to examine the correlation between the disappearance of PT and hemodynamic alterations. To reveal the hydroacoustic characteristics of disparate segments of venous return, a computational fluid dynamics (CFD) technique combined with the transcranial color-coded Doppler method was performed. When the ipsilateral IJV was compressed, PT disappeared, as the mean velocity of mainstream sinus flow and diverticular vortex decreased by 51.2 and 50.6%, respectively. The vortex inside the diverticulum persisted in 18 of 19 subjects. The CFD simulation showed that the flow amplitude generated inside the transverse–sigmoid sinus was segmental, and the largest flow amplitude difference was 20.5 dB. The difference in flow amplitude between the mainstream sinus flow and the diverticular flow was less than 1 dB. In conclusion, the sensation of PT is closely associated with the flow of kinetic energy rather than the formation of a vortex, whereby the amplitude of PT is correlated to the magnitude of the flow velocity and pressure gradient. Additionally, the range of velocity reduction revealed by the RCCD method may serve as a presurgical individual baseline curative marker that may potentially optimize the surgical outcomes.

Management of vascular causes of pulsatile tinnitus

Pulsatile tinnitus is a debilitating symptom affecting millions of Americans and can be a harbinger of hemorrhagic or ischemic stroke. Careful diagnostic evaluation of pulsatile tinnitus is critical in providing optimal care and guiding the appropriate treatment strategy. When a vascular cause of pulsatile tinnitus has been established, attention must be focused on the patient's risk of hemorrhagic stroke, ischemic stroke, or blindness, as well as the risks of the available treatment options, in order to guide decision-making. Herein we review our approach to management of the vascular causes of pulsatile tinnitus and provide a literature review while highlighting gaps in our current knowledge and evidence basis.