CTA/V detection of bilateral sigmoid sinus dehiscence and suspected idiopathic intracranial hypertension in unilateral pulsatile tinnitus

Cerebrospinal fluid flow dynamics and volume changes are related with sigmoid sinus wall dehiscence-pulsatile tinnitus with idiopathic intracranial hypertension

PURPOSE

To evaluate cerebrospinal fluid (CSF) flow dynamics and volume changes of pulsatile tinnitus (PT) patients induced by sigmoid sinus wall dehiscence (SSWD) with intracranial hypertension.

METHODS

Thirty-five SSWD-PT patients coexisted with intracranial hypertension and 35, age-, gender-, and handedness-matched healthy volunteers were prospectively enrolled and performed MRI. Clinical data were collected. CSF flow dynamics were evaluated by phase-contrast magnetic resonance imaging (PC-MRI) and CSF volume was measured using ITK-SNAP software.

RESULTS

Compared with controls, the body mass index (BMI) of PT patients increased significantly (P = 0.046). Among CSF flow dynamics, PT patients presented significantly decreased mean flux (MF) (P = 0.017), mean velocity (MV) (P = 0.038), peak velocity (PV) (P = 0.023), and significantly increased regurgitant fraction (RF) (P = 0.010) than controls. There were no significant differences in other CSF flow dynamics parameters between the groups. CSF volume of PT patients was significantly increased than controls (P = 0.024). RF and CSF volume had potential diagnostic value. The AUC, sensitivity, specificity and accuracy of RF and CSF volume were 0.678, 68.6 %, 60.0 %, 61.4 % and 0.656, 68.6 %, 57.1 %, 55.7 %, respectively. The combined diagnostic efficacy of RF and CSF volume was highest, and the AUC, sensitivity, specificity and accuracy were 0.733, 74.3 %, 62.9 %, 67.1 % respectively.

CONCLUSION

SSWD-PT patients present CSF flow dynamics and volume changes, which may be related to the occurrence of PT. In addition to structural abnormalities, the combination of RF and CSF volume can be innovative as a complementary index to identify SSWD as the accurate etiology of PT.

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.

Dynamics of cerebrospinal fluid pressure alterations and bilateral transverse-sigmoid sinus morphologies in Asian patients with venous pulsatile tinnitus

OBJECTIVE

This study was performed to investigate the dynamics of intracranial pressure (ICP) alterations and bilateral transverse-sigmoid sinus morphologies in patients with venous pulsatile tinnitus (PT).

METHODS

This retrospective study involved 27 patients with venous PT associated with sigmoid sinus wall anomalies. ICP and ICP metrics were measured by cerebrospinal fluid manometry and internal jugular vein compression tests. Correlation analysis was performed to determine the statistical correlation between ICP and the morphological metrics.

RESULTS

The mean ICP was 212.5 ± 47.3 mmH2O. The median Δ ICP total was 130 (range, 55-150) mmH2O. The Δ ICP total was linearly correlated with the open lumbar pressure, and a significant difference was found between patients with normal and elevated cerebrospinal fluid pressure. The Δ ICP difference was linearly correlated with the Len difference and Vol difference . Δ ICP was linearly correlated with Len difference .

CONCLUSIONS

Complete obstruction of flow patency should be avoided in patients with low ICP and large volumetric/patency differences in the bilateral transverse-sigmoid sinus systems.

Magnetic Resonance Imaging Findings in Idiopathic Intracranial Hypertension With and Without Pulsatile Tinnitus: An Age-Matched Cohort Study

OBJECTIVE

Many but not all patients with idiopathic intracranial hypertension (IIH) have pulsatile tinnitus (PT). However, little is known about why some patients with IIH develop PT and others do not. The purpose of this study was to determine if any of the classic magnetic resonance imaging (MRI)-detectable markers of IIH differ between patients with and without PT, thereby shedding light on potential pathophysiology.

METHODS

A retrospective age-matched cohort study of patients with documented IIH (diagnosed by neuro-ophthalmologist) was performed. All patients had MRI performed around the time of diagnosis. MRIs were assessed for 16 variables known to be associated with IIH (e.g., pituitary displacement/empty sella, optic nerve tortuosity, transverse sinus stenosis, inferior cerebellar tonsils, arachnoid granulations, slit-like ventricles) by two blinded neuroradiologists. All binary variables were analyzed via χ2 test with Yates correction, or Fisher exact when appropriate. Continuous variables were analyzed via Student t test. Inter-rater reliability for binary variables was assessed by Cohen κ. For continuous variables, intraclass correlation coefficient was calculated.

RESULTS

Forty age-matched patients with IIH met the inclusion criteria (20 with PT, 20 without PT). For all known binary MRI findings associated with IIH, there were no statistically significant differences between groups. Likewise, there were no statistically significant differences for continuous variables.

CONCLUSIONS

The classic MRI findings associated with IIH do not differ between patients with and without PT, suggesting that systemic (rather than localized intrinsic or extrinsic) factors may play a critical role in the pathophysiology.

CT evaluation of unilateral pulsatile tinnitus with jugular bulb wall dehiscence

OBJECTIVES

To investigate the imaging features of unilateral pulsatile tinnitus (PT) with jugular bulb wall dehiscence (JBWD).

METHODS

Computerized tomography angiography images of unilateral PT patients were reviewed between 2019 and 2021. Thirty-one symptomatic JBWD patients without sigmoid sinus wall dehiscence (SSWD) were included. Thirty-eight patients with SSWD were used as the control group. The prevalence of JBWD was calculated. The area and height of the jugular bulb, the extent of dehiscence, the presence of jugular bulb diverticulum, posterior condylar emissary vein (PCEV), oblique occipital sinus (OOS), venous outflow laterality (VOL), the degree of transverse sinus stenosis (TSS), and the pituitary height to sella turcica ratio were compared between the two groups.

RESULTS

The prevalence of JBWD was 12.1%, and JBWD was established as a causative diagnosis in 5.0% of unilateral PT patients. There were no statistical differences in the gender, symptomatic side, or VOL between the two groups. The area of the jugular bulb was larger and the height was higher (p_area < 0.001, p_height = 0.005). The prevalence of jugular bulb diverticulum was higher in the JBWD group (p = 0.002). The degree of symptomatic TSS was less severe (p < 0.001), and the prevalence of bilateral TSS was lower in the JBWD group (p < 0.001). The pituitary height to sella turcica ratio was greater (p = 0.004), the prevalence of PCEV (p = 0.014) was lower, and OOS (p = 0.015) was greater in the JBWD group.

CONCLUSIONS

The correlating factors of PT with JBWD and PT with SSWD are significantly different. These findings can further facilitate early and efficient PT treatment.

KEY POINTS

• The incidence of jugular bulb dehiscence (JBWD) accounted for approximately 12.1% in pulsatile tinnitus (PT) patients, and JBWD was established as a causative diagnosis in 5.0% of PT patients. • PT required large blood flows and abnormal flow patterns, whether in JBWD or sigmoid sinus wall dehiscence groups. • JBWD causing PT has some unique characteristic findings on CT.

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.

Association Between Sigmoid Sinusoidal Tinnitus and Low-Frequency Sensorineural Hearing Loss: A Retrospective Study at a Single Center

BACKGROUND We aimed to explore the correlation between patients' sigmoid sinusoidal tinnitus (SST) and low-frequency sensorineural hearing loss (LFSHL) and illustrate the underlying mechanism. MATERIAL AND METHODS Seven healthy volunteers with normal hearing were subjected to 125-, 250-, and 500-Hz pure sound and different white noise-masking intensities. A retrospective analysis was made on the clinical data and postoperative follow-up data of 59 patients with SST in the First Affiliated Hospital of Chongqing Medical University. The patients' sex, age, chief complaints, affected site, concomitant symptoms, course of disease, pure-tone audiometry (PTA) results, tinnitus discomfort loudness scale results, imaging examination, and complications were collected. RESULTS The results of the simulation experiment showed that the threshold of each frequency segment was higher after noise masking than before masking; the intensity of noise masking was positively correlated with hearing loss, and the changes of the hearing threshold of the 3 frequencies before and after masking were statistically significant (P<0.05). Fifty-nine patients with SST were documented between January 2015 and January 2020. After the operation, their low-frequency hearing was recovered to normal; 11 cases had significantly alleviated tinnitus and 9 cases were cured. CONCLUSIONS SST often causes corresponding pseudo-low-frequency hearing loss due to the noise-masking effect. The center frequency of tinnitus appears not to be 250-Hz or 500-Hz octave frequency of PTA, barring the detection of the pseudo-hearing loss in the audiometry chart of most patients. Surgery positively affects patients with SST, and the pseudo-LFSHL can be completely recovered after the operation as a result of tinnitus elimination.

CT venography correlate of transverse sinus stenosis and venous transstenotic pressure gradient in unilateral pulsatile tinnitus patients with sigmoid sinus wall anomalies

Objectives

To investigate the correlation between transverse sinus stenosis (TSS) and transstenotic pressure gradient (TPG) in unilateral pulsatile tinnitus (PT) patients with sigmoid sinus wall anomalies (SSWA).

Methods

Fifty-seven patients with unilateral venous PT were retrospectively included. All of them underwent CT venography and catheter manometry, accompanied with SSWA. The degree, length, shape (intrinsic/extrinsic/dysplasia), location (proximal/middle/distal, referring to the relative position of TSS and the Labbé vein junction) of TSS, the types of SSWA (dehiscence/diverticulum), and the degree of transverse sinus outflow laterality were assessed, and the correlations with ipsilesional TPG were analyzed.

Results

The mean value of ipsilesional TPG was 7.61 ± 0.52 mmHg. The degree and length of ipsilesional TSS were positively correlated with TPG (p < 0.001, p’ < 0.001), respectively. TPG was significantly larger in patients with contralateral transverse sinus dysplasia than those without (p = 0.023) and significantly smaller in patients with ipsilesional sigmoid sinus diverticulum than those with isolated dehiscence (p = 0.001). No statistical difference in TPG was shown between ipsilesional TSSs of different shapes or locations (p > 0.05). No correlation was noted between the degree of ipsilesional transverse sinus outflow laterality and TPG (p = 0.051). Stepwise linear regression indicated that the degree (β = 9.207, 95% CI = 3.558–14.856), length (β = 0.122, 95% CI = 0.025–0.220) of ipsilesional TSS, and contralateral transverse sinus dysplasia (β = 1.875, 95% CI = 0.220–3.530) were significantly correlated with TPG (R² = 0.471).

Conclusions

The degree, length of ipsilesional TSS, and contralateral transverse sinus dysplasia may be used to predict TPG in unilateral PT patients with SSWA.

Key Points

• CT venography may act as a screening tool to help low-probability unilateral pulsatile tinnitus (PT) patients with sigmoid sinus wall anomalies (SSWA) avoid invasive catheter manometry.

• The degree and length of ipsilesional transverse sinus stenosis (TSS) are positively correlated with transtenotic pressure gradient (TPG) in unilateral PT patients with SSWA.

• Ipsilesional TPG is larger in unilateral PT patients with contralateral transverse sinus dysplasia than those without and is smaller in unilateral PT patients with sigmoid sinus diverticulum than those with isolated dehiscence.

Longitudinal analysis of surgical outcome in subjects with pulsatile tinnitus originating from the sigmoid sinus

A dominant sigmoid sinus with either diverticulum or dehiscence (SS-Div/SS-Deh) is a common cause of pulsatile tinnitus (PT). For PT originating from SS-Div/SS-Deh, an etiology-specific and secure reconstruction using firm materials is vital for optimal outcomes. As a follow-up to our previous reports on transmastoid SS resurfacing or reshaping for SS-Div/SS-Deh, this study aimed to evaluate the long-term results of transmastoid resurfacing/reshaping. We retrospectively reviewed 20 PT patients who were diagnosed with SS-Div/SS-Deh, underwent transmastoid resurfacing/reshaping, and were followed up for more than 1 year postoperatively. For PT, immediate and long-term changes (> 1 year) in loudness and annoyance were analyzed using the visual analog scale (VAS). Additionally, pre and postoperative objective measurements of PT using transcanal sound recording and spectro-temporal analysis (TSR-STA), imaging results, and audiological findings were comprehensively analyzed. Significant improvements in PT were sustained or enhanced for > 1 year (median follow-up period: 37 months, range: 12–54 months). On TSR-STA, both peak and root mean square amplitudes decreased after surgery. Also, the average pure-tone threshold at 250 Hz improved after surgery. Thus, our long-term follow-up data confirmed that the surgical management of PT originating from SS-Div/SS-Deh is successful with regard to both objective and subjective measures.

Why does unilateral pulsatile tinnitus occur in patients with idiopathic intracranial hypertension?

PURPOSE

To investigate the relevant factors of unilateral pulsatile tinnitus (PT) in patients with idiopathic intracranial hypertension (IIH) using CT.

METHODS

CT angiography images of IIH patients with unilateral PT (n = 19), without PT (n = 13), and controls (n = 32) were reviewed. The characteristics including transverse sinus stenosis (TSS), venous outflow laterality (VOL), sigmoid sinus wall dehiscence (SSWD), and sigmoid sinus diverticulum (SSD) were quantitatively or/and qualitatively detected. VOL was compared between the symptomatic side of IIH patients with PT and the larger side of IIH patients without PT and the controls. TSS, SSWD, and SSD were compared between the symptomatic side of IIH patients with PT, and both sides of the latter two groups.

RESULTS

There was no statistical difference in body mass index or cerebrospinal fluid pressure between IIH patients with and without PT. The prevalence of TSS was significantly higher in IIH patients than that in the controls (p = 0.000), but TSS had no correlation with PT within IIH patients. The prevalence of SSWD successively decreased in IIH patients with PT, without PT, and the controls, with significant differences between each two of three groups (p = 0.000, p' = 0.000, p″ = 0.031). The proportion of VOL and the prevalence of SSD were significantly larger in IIH patients with PT than in the latter groups respectively (p_VOL = 0.005, p'_VOL = 0.000; p_SSD = 0.040, p'_SSD = 0.000). All SSDs in IIH patients with PT were accompanied with SSWD.

CONCLUSION

The dominant VOL and ipsilateral SSWD with/without SSD may be correlated with the occurrence of unilateral PT in IIH patients.

The styloid process and the formation of sigmoid sinus diverticulum: is there a link?

INTRODUCTION

Sigmoid sinus diverticulum has been considered the most common cause of pulsatile tinnitus; the mechanism underlying sigmoid sinus diverticulum formation is unclear. To the best of our knowledge, no previous studies have assessed whether the formation of sigmoid sinus diverticulum is related to compression of the internal jugular vein by the styloid process.

OBJECTIVE

To discuss the relationship between the styloid process and the formation of sigmoid sinus diverticulum.

METHODS

The medical records of nine patients diagnosed with venous pulsatile tinnitus caused by sigmoid sinus diverticulum were reviewed between April 2009 and May 2019. All patients underwent high-resolution computed tomography of the temporal bones, computed tomography venogram of the head and neck, magnetic resonance venography, and brain magnetic resonance imaging. The length and medial angulation of the styloid process were measured, and compression of the internal jugular vein was recorded.

RESULTS

The study population consisted of nine female right-sided pulsatile tinnitus patients with a mean age of 53.8±4.6 years. The mean lengths of the styloid process were 3.9±0.6cm on the right side and 4.1±0.7cm on the left side. The mean medial angulation of the styloid process was significantly smaller on the right side than the left side (65.3°±1.2° vs. 67.8°±1.7°, p<0.05). In addition, computed tomography venogram of the head and neck demonstrated the left internal jugular vein was compressed by the styloid process in eight of the nine patients.

CONCLUSION

The formation of sigmoid sinus diverticulum with venous pulsatile tinnitus may be related to compression of the contralateral internal jugular vein by the styloid process. However, accumulation of data in additional cases is required to verify this suggestion.