Sigmoid Sinus Diverticulum, Dehiscence, and Venous Sinus Stenosis: Potential Causes of Pulsatile Tinnitus in Patients with Idiopathic Intracranial Hypertension?

The Pseudotumor Cerebri Syndrome

Pseudotumor cerebri syndrome is a syndrome of increased cerebrospinal fluid pressure without ventriculomegaly, mass lesion, or meningeal abnormality. It is either primary (idiopathic intracranial hypertension, IIH) or secondary. A secondary cause is unlikely when adhering to the diagnostic criteria. Permanent visual loss occurs if undetected or untreated, and the associated headaches may be debilitating. Fulminant disease may result in blindness despite aggressive treatment. This study addresses the diagnosis and management of IIH including new insights into the pathobiology of IIH, updates in therapeutics and causes of overdiagnosis.

Clinical Predictors of Pulsatile Tinnitus in Patients With Idiopathic Intracranial Hypertension: An Age-Matched Cohort Study

INTRODUCTION

Pulsatile tinnitus (PT) occurs in many but not all patients with idiopathic intracranial hypertension (IIH). It is poorly understood why some patients with IIH develop PT, yet others do not. The purpose of this study was to determine if any clinical findings differ between those with and without PT in IIH, potentially shedding light on a pathophysiologic mechanism.

METHODS

Age-matched cohort analysis of patients with documented IIH and presence or absence of PT was performed, collecting data including body mass index (BMI), blood pressure, visual acuity, cerebrospinal fluid (CSF) opening pressure, sleep apnea, migraines, and transient visual obscurations, among others. Independent-sample t test and χ2 test were used to analyze continuous and binary variables, respectively, with multivariate analysis conducted including variables statistically significant on univariate analysis.

RESULTS

Eighty subjects with IIH met the inclusion criteria (40 PT+, 40 PT-). CSF opening pressure showed no significant difference between the two groups. The PT+ cohort was found to have an average BMI of 45.1 kg/m 2 , which was significantly higher than the PT- group (37.7 kg/m 2 ; p = 0.0023). PT+ pulse pressure (60.1 mm Hg) was also significantly higher than the PT- group (51.6 mm Hg; p = 0.019). PT+ patients were also significantly more likely to have sleep apnea ( p < 0.001) and migraines ( p = 0.0036). Multiple logistic regression revealed an adjusted odds ratio of 13.9 for sleep apnea, 4.1 for migraines, and 1.01 for every increase in unit of BMI.

CONCLUSION

Among patients with IIH, presence of PT is associated with higher BMI and pulse pressure, and increased incidence of sleep apnea and migraines. Given no significant difference in CSF pressures between the two groups, PT may not be a product of increased disease severity but may be related to sequelae of obesity, such as increased pulse pressure and sleep apnea.

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.

Radiographic Sigmoid Sinus Wall Abnormalities and Pulsatile Tinnitus: A Case-Control Study

OBJECTIVE

Compare incidence of sigmoid sinus wall abnormalities (SSWAs) and other radiographic abnormalities in patients with pulsatile tinnitus (PT) versus controls.

STUDY DESIGN

Retrospective case-control.

SETTING

Tertiary referral center.

PATIENTS

Adults with PT and high-resolution computed tomography imaging were compared with adults undergoing cochlear implant workup including high-resolution computed tomography imaging.

MAIN OUTCOME MEASURES

Incidence of SSWA in PT cohort (n = 141) compared with control (n = 149, n = 298 ears). Secondary outcome measures included differences in demographics and in other radiographic abnormalities between cohorts.

RESULTS

Patients with PT had a higher incidence of SSWA (34% versus 9%, p < 0.001) and superior canal dehiscence (23% versus 12%, p = 0.017) than controls. Spearman product component correlations demonstrated that ipsilateral PT was weakly associated with SSWA ( r = 0.354, p < 0.001). When SSWA was present in the PT cohort (n = 48 patients, n = 59 ears), in 31 cases (64.6%), the SSWA correlated with PT laterality (e.g., left SSWA, left PT); in 12 (25.0%), SSWA partially correlated with PT laterality (e.g., bilateral SSWA, right PT); and in 5 (10.4%), the SSWA did not correlate with PT laterality (e.g., right SSWA, left PT).

CONCLUSIONS

For our patients with both PT and SSWA, the SSWA is likely a contributing factor in approximately 65% of cases. For a third of patients with PT and concomitant SSWA, the association between the two is either not causative or not solely causative. Surgeons counseling patients with PT and SSWA may be optimistic overall regarding sigmoid resurfacing procedures but must appreciate the possibility of treatment failure, likely because of untreated comorbid conditions.

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.

Dynamic Volume Computed Tomography for Characterizing Pulsatile Tinnitus Caused by Sigmoid Sinus Diverticulum with Bone Defects: Clinical Implications

OBJECTIVE

The objective of this study is to investigate the diagnosis of dynamic volume computed tomography (CT) for pulsatile tinnitus caused by sigmoid sinus diverticulum (SSD) and bone defects.

METHODS

Data obtained by dynamic volume CT from 35 patients with SSD were retrospectively collected. Then the ear morphological parameters, including bone defect, transverse sinus stenosis, position of the jugular bulb, jugular bulb diverticulum, defect of the jugular bulb wall, gross venous sinus thrombosis and SSD, and blood perfusion parameters, including cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT), were evaluated and compared between the tinnitus side and the asymptomatic side of the ear.

RESULTS

The maximum diameters of the bone defects on the tinnitus side were greater than those on the asymptomatic side (Horizontal 6.36±2.35mm vs. 1.12±0.78mm; Longitudinal 4.87±1.25 vs. 0.88±0.06mm). Dynamic volume CT visually displayed the SSD herniated into the adjacent mastoid via the bone defect. Transverse sinus stenosis, high position of the jugular bulb, jugular bulb diverticulum, defect of the jugular bulb wall, and gross venous sinus thrombosis were present more frequently on the tinnitus side than on the asymptomatic side (P < 0.05). Moreover, CBF, CBV, and MTT were significantly greater on the tinnitus side than on the asymptomatic side (P < 0.05).

CONCLUSION

Dynamic volume CT examination is an effective method for the diagnosis of pulsatile tinnitus caused by SSD with bone defects.

Evaluation of Clinical Findings with MRI Venography in Patients with Idiopatic Intracranial Hypertension

OBJECTIVES

To evaluate clinical data and Magnetic Resonance Venography (MRV) findings together in patients with idiopathic intracranial hypertension (IIH).

MATERIALS AND METHODS

In this retrospective study between January 2009 and February 2021, conventional MRI and MRV examinations were performed on 30 patients who were admitted to the neurology service of Erciyes University Medical Faculty with the pre-diagnosis of IIH, cerebrospinal fluid (CSF) pressure was measured in these patients to confirm the diagnosis of IIH. Transverse Sinus Stenosis Ratio (TS SR), Superior Sagittal Sinus (SSS) diameter, Sinus Rectus (SR) diameter, Stenosis Segment Length (SSL) were studied.

RESULTS

High CSF pressure was detected in 22 of 30 patients with IIH pre-diagnosis. CSF pressure was normal in 8 cases. TS SR was compared in all groups, right TS SR 0.63 ± 0.16, Left TS SR 0.55 ± 0.16 in the patient group with IIH, right TS SR 0.55 ±0.16 in the CSF pressure normal patient group, Right TS SR 0.28 ± 0.07 Left TS SR 0.31 ± 0.07 in the control group Right TS SR It was 0.28 ± 0.09, Sol TS SR was 0.30 ± 0.07.

CONCLUSION

Before LP, the cranial venous system must be monitored. TS SR and CSF pressure are directly proportional. The stenosis rate is important for IIH rather than SSL.

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.

Systematic Evaluation of the Efficacy of Acupuncture Associated with Physical and Mental Intervention when Treating Idiopathic Tinnitus and the Improvement of Tinnitus Symptoms

Objective

To systematically evaluate the efficacy of acupuncture associated with physical and mental intervention when treating idiopathic tinnitus and the improvement of tinnitus symptoms, so as to supply evidence-based medicine for its popularization and adoption.

Methods

PubMed, EMBASE, ScienceDirect, Cochrane Library, China knowledge Network Database (CNKI), China VIP Database, Wanfang Database, and China Biomedical Literature Database (CBM) online database were searched for the controlled trial of acupuncture associated with physical and mental intervention when treating idiopathic tinnitus. The retrieval time limit is from January 2010 to March 2022. Separately, two researchers extracted the data, and according to the Cochrane Handbook 5.3, the bias risk of each piece of literature was assessed. The collected data were measured using RevMan5.3 statistical software.

Results

Finally, 5 CT articles were included in this study, with a total sample size of 282. Meta-analysis showed that the effective rate of the study group was significantly higher than that of the control group (P < 0.05). The scores of tinnitus disorder scale (THI) after treatment were analyzed by Meta. The THI scores of the study group after treatment were significantly lower than those before treatment. Meta-analysis of the severity of tinnitus after treatment showed that the severity of tinnitus in the observation group after treatment was significantly lower than that before treatment. There is a certain publication deviation in the literature, which may be related to the heterogeneity of the research and the small number of literatures.

Conclusion

On the basis of acupuncture treatment, associated with physical and mental intervention is helpful to the recovery of patients with idiopathic tinnitus, can effectively improve their clinical symptoms, and is suitable for clinical application. A popularization of this concept in clinical practice is worth considering, but further research and follow-up with a higher methodological quality and longer intervention time are needed to confirm its efficacy.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension-From Physiopathology to Treatment

In this review, we provide an update on the pathogenesis, diagnosis, and management of adults with idiopathic intracranial hypertension (IIH) and implications of the cerebral venous system, highlighting the progress made during the past decade with regard to mechanisms of the venous outflow pathway and its connection with the cerebral glymphatic and lymphatic network in genesis of IIH. Early diagnosis and treatment are crucial for favorable visual outcomes and to avoid vision loss, but there is also a risk of overdiagnosis and misdiagnosis in many patients with IIH. We also present details about treatment of intracranial hypertension, which is possible in most cases with a combination of weight loss and drug treatments, but also in selected cases with surgical interventions such as optic nerve sheath fenestration, cerebral spinal fluid (CSF) diversion, or dural venous sinus stenting for some patients with cerebral venous sinus stenosis, after careful analysis of mechanisms of intracranial hypertension, patient clinical profile, and method risks.

Transtemporal Sigmoid Sinus Decompression: A Novel Surgical Procedure for the Treatment of Idiopathic Pulsatile Tinnitus

OBJECTIVE

Idiopathic pulsatile tinnitus (IPT) is associated with high patient morbidity although treatment methods remain unsatisfactory. In the present study, the transtemporal sigmoid sinus decompression is used in the treatment of idiopathic pulsatile tinnitus.

STUDY DESIGN

Retrospective case study.

SETTING

Tertiary referral center.

PATIENTS

From 2005 to 2020, 287 patients presented with a complaint of pulsatile tinnitus. After exclusion criteria, 25 patients were diagnosed with IPT. Those patients underwent treatment and were included in a retrospective study.

INTERVENTIONS

Following failed conservative therapies, the primary author performed a transtemporal sigmoid sinus decompression surgery on the patients under general anesthesia.

MAIN OUTCOME MEASURES

Long-term resolution of IPT was measured using the Tinnitus Handicap Inventory (THI). Outcome measurements were taken preoperatively, immediately postoperatively, three months postoperatively, and the status of all 25 patients is known at the time of this study.

RESULTS

Transtemporal sigmoid sinus decompression was performed on 25 patients (mean age: 51.7 years, 80.0% female). Out of the 25 patients, 23 (92.0%) patients experienced complete resolution of their IPT. Statistically significant differences based on preoperative THI (mean THI: 4.19) were evident immediately after surgery (mean THI: 1.31; p < 0.001), at 3 months postoperatively (mean THI: 1.19; p < 0.001), and over a mean follow-up time of 68.7 months (range, 3-168 months) (mean THI: 1.38; p < 0.001). Out of the two patients considered unsuccessful, Case 21 experienced a partial resolution. No major postoperative complications occurred.

CONCLUSIONS

Transtemporal sigmoid sinus decompression is a safe and effective surgical procedure demonstrated to give near total resolution in properly selected patients and provides long-term relief for patients with IPT.

Transverse Sinus Stenosis in Venous Pulsatile Tinnitus Patients May Lead to Brain Perfusion and White Matter Changes

Objective: Transverse sinus stenosis (TSS) is associated with various symptoms, but whether it can lead to pathological brain changes is unclear. This study aimed to investigate brain changes in venous pulsatile tinnitus (PT) patients with TSS.

Materials and Methods: In this study, fifty-five consecutive venous PT patients and fifty age- and gender-matched healthy controls (HCs) were investigated. In CT venography, the combined conduit score (CCS) was used to assess the degree of TSS in venous PT patients. Magnetic resonance venography was used to assess TSS in HCs. All the participants had undergone arterial spin labeling and structural MRI scans.

Results: Two patients without TSS and ten HCs with TSS were excluded. Fifty-three venous PT patients with TSS and 40 HCs without TSS were included in this study. All the patients had unilateral cases: 16 on the left and 37 on the right. Based on the CCS, the patients were divided into high-degree TSS (a score of 1–2) (n = 30) and low-degree TSS groups (a score of 3–4) (n = 23). In the whole brain and gray matter, the patients with high-degree TSS showed decreased cerebral blood flow (CBF) compared with patients with low-degree TSS as well as HCs (P < 0.05), and no significant difference in CBF was found in patients with low-degree TSS and HCs (P > 0.05). In white matter (WM) regions, the patients with high-degree TSS exhibited decreased CBF relative to the HCs (P < 0.05). The incidence of cloud-like WM hyperintensity was significantly higher in the above two patient groups than in the HC group (P < 0.05).

Conclusion: TSS in venous PT patients may lead to decreased CBF and cloud-like WM hyperintensity. These neuroimaging findings may provide new insights into pathological TSS in venous PT.

Anatomic Variation of the Lateral Sinus in Patients With Idiopathic Intracranial Hypertension: Delineation With Black-Blood Contrast-Enhanced MRI

Objectives: The purpose of this study was to describe the peculiar anatomic variations in the lateral sinus and analyze the patterns of cerebrospinal fluid (CSF) drainage by using high-resolution (HR) black-blood (BB) contrast-enhanced magnetic resonance imaging (MRI) in patients with idiopathic intracranial hypertension (IIH).

Methods: Total 33 IIH patients who were found cerebral venous sinus stenosis (CVSS) by MR venography (MRV) were enrolled in this study. HR-BB contrast-enhanced MRI was used to assess the features of anatomical variations in transverse sinus and sigmoid sinus. The development of bilateral sinuses was firstly evaluated, including unilateral hypoplasia with contralateral dominance or bilateral balanced development. Then, four kinds of anatomical variations were eventually recorded, including circumscribed stenosis, arachnoid granulation (AG), fibrous septum (FS), and brain herniation (BH) into dural venous sinus (DVS).

Results: Bilateral venous drainage dysfunction was found in 30(90.9%) patients, whereas only 3(9.1%) patients presented unilateral venous drainage dysfunction. There was no difference in clinical symptoms between the two groups. The most common case is hypoplasia in unilateral sinus combined with anatomic variation in the contralateral dominant transverse sinus such as AG and BH into DVS. Total of 52 anatomic variations were finally found in bilateral sinuses in 33 enrolled patients, including 19(36.5%)AGs, 12(23.1%)FS, 7(13.5%) BH into DVS and 14(26.9%) circumscribed stenoses. Moreover, 41(62.1%) lateral sinuses showed enhancement in T1-weight-enhanced MRI.

Conclusions: Patients with CVSS almost had CSF outflow disorders, whatever bilateral equalization or unilateral hypoplasia with contralateral dominance. Four types of main anatomic variations, including circumscribed stenosis, AG, FS, and BH into DVS, caused venous reflux obstruction by elevating the intracranial press (ICP).

Effect of Emissary Vein on Hemodynamics of the Transverse- Sigmoid Sinus Junction

Objective: To investigate the effect of the blood flow direction and afflux location of emissary veins (EVs) on the hemodynamics of the transverse-sigmoid sinus (TS-SS) junction.

Methods: A patient-specific geometric model was constructed using computed tomography venography (CTV) and 4D flow MR data from a venous pulsatile tinnitus (PT) patient. New EV models were assembled with the afflux at the superior, middle and inferior portions of the SS from the original model, and inlet and outlet directions were applied. Computational fluid dynamics (CFD) simulation was performed to analyze the wall pressure and flow pattern of the TS-SS junction in each condition.

Results: Compared to the model without EVs, the wall pressure was greatly increased in models with inlet flow and greatly decreased in models with outlet flow. The more closely the EV approached the TS-SS, the larger the pressure in models with inlet flow, and the smaller the pressure in models with outlet flow. The flow streamline in the lateral part of the TS-SS junction was smooth in all models. The streamlines in the medial part were regular spirals in outlet models and chaotic in inlet models. The streamlines showed no obvious changes regardless of afflux location. The velocity at the TS-SS junction of inlet models were uniform, medium-low flow rate, while in control and outlet models were the lateral high flow rate and the central low flow rate.

Conclusion: The flow direction and afflux location of EVs affect the hemodynamics of the TS-SS junction, which may influence the severity of PT.

Venous Causes of Pulsatile Tinnitus: Clinical Presentation, Clinical and Radiographic Evaluation, Pathogenesis, and Endovascular Treatments: A Literature Review

Tinnitus is an abnormal perception of a sound without external stimulation. Venous pulsatile tinnitus (VPT) is a specific form of tinnitus characterized by an objective and often subjective bruit that occurs as a result of localized venous abnormalities. Clinical evaluation relies on sound quality, duration, and precipitating factors. Idiopathic intracranial hypertension (IIH) and transverse sinus stenosis (TSS) are among the most common causes of VPT. Other causes include sigmoid sinus wall abnormalities (SSWAs), jugular vein anomalies (JVAs), and emissary veins anomalies. These anomalies can be detected on magnetic resonance imaging, magnetic resonance angiography/magnetic resonance venography, and high-resolution temporal bone computed tomography. The pathogenesis behind the VPT includes turbulent blood flow as a result of luminal stenosis or abnormal dilation, amplification of internal sound due to temporal bone defects, and abnormal position of the venous sinus system structures adjacent to the bony structures of the auditive apparatus. Based on these theories, different interventional treatment modalities can be applied to treat the underlying causes. Endovascular treatments have shown high efficacy and safety among those treatments which include stenting of the lateral sinus stenosis in IIH and TSS, coiling of the SSWA and JVA, and embolization of emissary veins anomalies. Further studies are needed to understand the natural history of these anomalies and the efficacy of treatments of VPT, which-unlike other types of tinnitus-can be cured with proper treatment.

Imaging Characteristics of Sigmoid Sinus Wall Anomalies, Idiopathic Intracranial Hypertension, and Spontaneous CSF Leaks

OBJECTIVE

To assess the frequency of radiographic features of elevated intracranial pressure (ICP) in patients with sigmoid sinus wall anomalies (SSWA) and compare to those in idiopathic intracranial hypertension (IIH) and spontaneous CSF (sCSF) leaks.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care center.

PATIENTS

110 patients - 62 SSWAs, 19 IIH, 29 sCSF leaks.

MAIN OUTCOME MEASURES

Demographics, comorbidities and radiographic features by diagnosis.

RESULTS

Imaging findings indicative of elevated ICP were similar across all three groups, as were body mass index, hyperlipidemia and diabetes. On univariate analysis, sCSF leak patients were significantly older than SSWA (60 vs. 41 years, p < 0.001) and IIH (60 vs. 40 years, p < 0.001) patients. They had a greater prevalence of arachnoid granulations than SSWA (75.8% vs. 37.1%, p < 0.01) and tegmen dehiscence than both SSWA and IIH (93.1% vs. 75.8% vs. 57.8%, p = 0.01), though a lower prevalence of empty sella than SSWA (44.8% vs. 72.5%, p < 0.001). SSWAs were present in roughly 44.3% of IIH and sCSF leak patients, and IIH in roughly 15.8% of SSWA and sCSF leak patients. Age (OR = 1.1, p = 0.001), hypertension (OR = 8.3, p = 0.01) and empty sella (OR = 0.1, p = 0.01) were predictive of sCSF leaks compared to SSWAs on multivariate analysis.

CONCLUSIONS

Many radiographic and clinical features of elevated ICP are found at similar rates among patients with SSWA, IIH and sCSF leaks, suggesting a common underlying process. SSWAs seem to present earlier along this spectrum of phenotypes, while sCSF leaks present later. Differences in age, metabolic syndrome and ICP may influence a patient's clinical presentation.

State of the Art: Venous Causes of Pulsatile Tinnitus and Diagnostic Considerations Guiding Endovascular Therapy

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.

Posterior Skull Base Anatomy and Pathology

A posterior skull base lesion is an uncommon radiological finding that may be noted incidentally or during targeted imaging of patients with clinical symptoms attributable to the lesion. It may be inflammatory or neoplastic in etiology, or may simply be an anatomic variant or a "don't-touch" lesion that should not be misinterpreted as something more ominous. A systematic approach to the evaluation of the posterior skull base is therefore required in order to differentiate lesions requiring immediate attention from those requiring a less urgent course of action or none at all. This review will focus on the imaging features of pathologic conditions that are more commonly encountered in posterior skull base CT and MR examinations.

Detecting causes of pulsatile tinnitus on CT arteriography-venography: A pictorial review

Pulsatile tinnitus (PT) can be a mild or debilitating symptom. Following clinical examination and otoscopy, when the underlying aetiology is not apparent, radiological imaging can be used to evaluate further. CT arteriography-venography (CT A-V) of the head and neck has recently been introduced as a single 'one catch' modality for identifying the many causes of PT including those which are treatable and potentially serious whilst also providing reassurance through negative studies or studies with benign findings. CT A-V is performed as a single phase study allowing both arterial and venous assessment, hence limiting radiation exposure. Additional multiplanar reformats and bone reconstructions are desirable. Understanding the limitations of CT A-V is also required, with an awareness of the scenarios where other imaging modalities should be considered. The causes of PT can be divided into systemic and non-systemic categories. Non-systemic aetiologies in the head and neck should be carefully reviewed on CT A-V and include a variety of vascular causes (arteriovenous malformations/fistulas, venous or arterial aetiologies) and non-vascular causes (tumours and bony dysplasias). Venous causes (dominant, aberrant, stenosed or thrombosed venous vessels) are more common than arterial aetiologies (aberrant or stenosed internal carotid artery, aneurysms or a persistent stapedial artery). Glomus tumours that are not visible on otoscopy and osseous pathologies such as bony dehiscence and otospongiosis should also be excluded. Careful assessment of all the potential vascular and non-vascular causes should be reviewed in a systematic approach, with correlation made with the clinical history. A structured reporting template for the reporting radiologist is provided in this review to ensure all the potential causes of PT are considered on a CT A-V study. This will help in providing a comprehensive radiological evaluation, hence justifying the radiation dose and for patient assessment and prognostication.

Lateralization effects in brain white matter reorganization in patients with unilateral idiopathic tinnitus: a preliminary study

Idiopathic tinnitus can cause significant auditory-related brain structural and functional changes in patients. However, changes in patterns of the lateralization effects in idiopathic tinnitus have yet to be established, especially on white matter (WM) reorganization. In this study, we studied 19 left-sided and 19 right-sided idiopathic tinnitus (LSIT, RSIT) patients and 19 healthy controls (HCs). We combined applied voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analyses to investigate altered features of the auditory-related brain WM. We also conducted correlation analyses between the clinical variables and WM changes in the patients. Compared with the HCs, both sided tinnitus patients showed significant auditory-related brain WM alterations. More interestingly, the LSIT patients demonstrated a greater decrease in white matter volume (WMV) in the right medial superior frontal gyrus (SFG) than the RSIT; meanwhile, we also found that compared with the RSIT group, the LSIT group showed significantly increased fractional anisotropy (FA) in the body of the corpus callosum (CC), left cingulum, and right superior longitudinal fasciculus (SLF) and decreased mean diffusivity (MD) in the body of CC. Moreover, relative to the RSIT group, the LSIT group also exhibited increases in WM axial diffusivity (AD) in the left SLF, left cingulum, right middle cerebellar peduncle (MCP), left thalamus, and bilateral forceps major (FM) and decreases in radial diffusivity (RD) in the genu of CC. Additionally, the FA value of the right SLF was closely associated with tinnitus severity in the LSIT. Our study suggests that lateralization has a significant effect on WM reorganization in patients with idiopathic tinnitus; in particular, LSIT patients may experience more severe and widespread alterations in WMV and WM microstructure than the RSIT group, and all these changes are indirectly auditory related. These findings provide new useful information that can lead to a better understanding of the tinnitus mechanisms.

Relentless pulsatile tinnitus secondary to dural sinovenous stenosis: is endovascular sinus stenting the answer?

AIM

To assess the efficacy of endovascular venous sinus stenting (EVSS) in treating pulsatile tinnitus (PT) caused by dural venous sinus stenosis (DVSS), and to determine whether it is an adequate remedy in cases with concurrent venous anomalies.

MATERIALS AND METHODS

Seventeen patients (13 female and four male) with PT due to DVSS were treated using EVSS. The trans-stenotic pressure gradient (PG) was measured before and after stenting. The effect of stenting on the tinnitus was evaluated by questioning the patients at day 0, and at 3, 6, and 9 months after stenting.

RESULTS

Except for one patient who continued to complain of PT, all of the patients, including two with concomitant sinus diverticula, described complete resolution of the tinnitus immediately following stenting. The post-stenting PG was significantly lower than the pre-stenting PG (p<0.0001). No procedure related complications occurred and no recurrence was recorded during the follow-up period.

CONCLUSION

EVSS is a safe and successful treatment for PT due to DVSS even in cases with coexistent sinus diverticula.

Beyond Tympanomastoidectomy: A Review of Less Common Postoperative Temporal Bone CT Findings

Postoperative temporal bone imaging after surgical procedures such as ossiculoplasty, tympanomastoidectomy, cochlear implantation, and vestibular schwannoma resection is often encountered in clinical neuroradiology practice. Less common otologic procedures can present diagnostic dilemmas, particularly if access to prior operative reports is not possible. Lack of familiarity with the less common surgical procedures and expected postoperative changes may render radiologic interpretation challenging. This review illustrates key imaging findings after surgery for Ménière disease, superior semicircular canal dehiscence, temporal encephalocele repairs, internal auditory canal decompression, active middle ear implants, jugular bulb and sigmoid sinus dehiscence repair, and petrous apicectomy.

Hemodynamic study of the therapeutic effects of the different degrees of sigmoid sinus diverticulum reconstruction on patients

Sigmoid sinus diverticulum (SSD) is a common pathophysiology of pulsatile tinnitus (PT) and mainly treated by SSD reconstruction surgery. The degree of reconstruction is an important indicator of SSD reconstruction surgery, but its impact on the effect of SSD reconstruction is unclear. This study aimed to clarify the effect of the degree of SSD reconstruction on diverticulum reconstruction surgical treatment. One patient-specific case (control subject) was reconstructed based on the computed tomography angiography (CTA) images of patients with PT. The SSD reconstruction degree was used as a new index in this study. And the case of 30% (case 1), 60% (case 2), and 100% (case 3) of the diverticulum reconstruction degree of control subject were constructed. Transient-state computational fluid dynamics was performed. Wall pressure distribution, wall average pressure (P_avg) of SSD, flow pattern (velocity streamlines and velocity vector), wall shear stress (WSS) and averaged WSS (WSS_avg) were calculated and used in evaluating the hemodynamic differences among the DRD cases. Results demonstrated that change in SSD pressure was not linear with increase in DRD. The DRD that reached 60% of the original diverticulum was effective. At the peak point of the inlet boundary condition (T1 = 0.22s), the P_avg of SSD had a nonlinear change (control subject, 126.967 Pa vs. case 1, 126.274 Pa vs. case 2, 106.897 Pa vs. case 3, 94.116 Pa). Flow vorticity decreased gradually, and the smoothness of the streamlines increased with DRD. WSS_avg slightly changed with increasing DRD. The high-speed flow blood hit the diverticulum entrance and then swirled to hit the area of the sigmoid sinus wall abnormal. It was concluded that flow patterns related to PT differ with DRD. In diverticulum reconstruction surgery, there is a threshold value, and only when the DRD exceeds this value (60% or 70% or 80%), it will have a noticeable effect. In this study, DRD should at least reach 60% of the original diverticulum. When DRD is insufficient, hemodynamic change in the diverticulum is small, and the PT may have remained. SSD may be caused by high-speed blood flow.

Venous sinus stenting for the treatment of isolated pulsatile tinnitus: Results of a prospective trial

OBJECTIVES

This prospective study evaluates the effectiveness and safety of venous sinus stenting for patients with isolated pulsatile tinnitus and lateral sinus stenosis.

METHODS

Patients with isolated pulsatile tinnitus and lateral sinus stenosis with a minimum trans stenotic gradient of 4 mm Hg were treated with stenting. Pulsatile tinnitus before and after treatment was assessed with the Tinnitus Handicap Inventory (THI). Periprocedural adverse events, neurological complications, clinical and radiographic follow-up were also recorded.

RESULTS

A total of 42 patients (41 females and 1 male) were included in the study (median age of 37.5 years). Thirty patients had post-stenotic fusiform and 12 had post-stenotic saccular venous sinus aneurysm. In addition to stenting, coils were used to treat the patients with saccular venous aneurysms. The median follow-up was 5 months (range 1 to 34 months). Most patients had complete (39/42) or near-complete (2/42) resolution of their pulsatile tinnitus post-procedure. There were no serious adverse events.

CONCLUSION

Stenting of the lateral venous sinus is a safe and effective treatment for patients with isolated pulsatile tinnitus due to venous sinus stenosis.

Association of pulse synchronous tinnitus and sigmoid sinus wall abnormalities in patients with idiopathic intracranial hypertension

PURPOSE

Pulse synchronous tinnitus (PT) is common in patients with idiopathic intracranial hypertension (IIH) and in those with sigmoid sinus wall abnormalities (SSWAs). Although patients with SSWAs and IIH share many clinical features, the incidence of SSWAs in patients with IIH and its relationship to PT in this cohort is less well established. The purpose of this study is to assess the incidence of SSWAs in patients with IIH and PT, and to determine if there is an association between SSWAs and PT in this population.

MATERIALS AND METHODS

Prospective computed tomography (CT) study of adults with IIH. Subjective PT was correlated with presence or absence of SSWAs on CT.

RESULTS

22 subjects were enrolled and 14 subsequently underwent CT. The incidence of SSWAs was significantly higher in subjects with PT than without (70% vs. 0%, p = 0.02). Mean age, BMI and opening pressures did not differ between those with and without SSWAs or PT.

CONCLUSIONS

There is a high incidence of SSWAs in subjects with IIH and PT. These findings support an association between SSWAs and PT, and implicate SSWAs as a possible cause of, or contributing factor to, PT in patients with IIH. Patients with IIH and PT that does not resolve with reducing intracranial pressure should undergo diagnostic CT and consider treatment of a SSWA if present.

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.

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.

Prevalence of Sigmoid Sinus Dehiscence and Diverticulum among Adults with Skull Base Cephaloceles

BACKGROUND AND PURPOSE

Cephaloceles are relatively rare conditions caused by a congenital and/or acquired skull defect. The incidence of associated venous brain anomalies with regard to cephaloceles remains to be fully elucidated. Accordingly, we sought to assess the prevalence of sigmoid sinus dehiscence and diverticula in patients with spontaneous skull base cephaloceles.

MATERIALS AND METHODS

Our institutional data base was retrospectively queried from 2005 to 2018. Patients in whom spontaneous skull base cephaloceles were identified were ultimately included in the study cohort. These patients subsequently had their sigmoid sinuses re-evaluated with focused attention on the possible presence of dehiscence and/or diverticula.

RESULTS

We identified 56 patients: 12 men and 44 women. After re-evaluation of the sigmoid sinuses, evidence of dehiscence and/or diverticula was noted in 21 patients. The right sigmoid sinus was involved in 11 patients, and the left sigmoid sinus was involved in 7 patients, including 3 cases of diverticulum. In 3 patients, evidence of bilateral sigmoid sinus dehiscence and diverticula was noted. Female sex was associated with sigmoid sinus dehiscence and diverticula by univariate analysis (P = .019). By linear regression, cephalocele volume was negatively associated with sigmoid sinus dehiscence and diverticula (coefficient, -2266, P value < .007, adjusted R ² = 0.1077). By univariate logistic regression using average cephalocele volume as a cutoff, we demonstrate a statistically significant finding of lower volumes being associated with sigmoid sinus dehiscence and diverticula with an odds ratio of 3.58 (P = .05).

CONCLUSIONS

The prevalence of sigmoid sinus dehiscence and diverticula in patients with cephalocele is high. Female sex is associated with sigmoid sinus dehiscence and diverticula. The cephalocele volume appears to be inversely proportional to sigmoid sinus dehiscence and diverticula.

Role of contrast-enhanced magnetic resonance high-resolution variable flip angle turbo-spin-echo (T1 SPACE) technique in diagnosis of transverse sinus stenosis

PURPOSE

Transverse sinus stenosis (TSS) is the most sensitive imaging characteristic of idiopathic intracranial hypertension (IIH). This study aimed to assess the diagnostic performance of contrast-enhanced magnetic resonance high-resolution variable flip angle turbo-spin-echo (T1 SPACE) technique in TSS patients and evaluate the diagnostic accuracy of enhanced T1 SPACE, and phase-contrast magnetic resonance venography (PC MRV) with digital subtraction angiography (DSA) as standard imaging.

METHOD

This prospective study enrolled 62 patients with suspected IIH and PC MRV-confirmed transverse sinus stenosis. All patients underwent lumbar puncture, PC MRV, enhanced T1 SPACE sequences and DSA examination. The accuracy, sensitivity, and specificity of enhanced T1 SPACE in detecting venous sinus stenosis were calculated and compared with those of PC MRV. Intermodality agreement (Kendall's rank correlation coefficients and weighted kappa statistic) was assessed.

RESULTS

Sixty-two patients were enrolled from November 2016 to October 2018. For the measured stenosis, better correlation was observed in enhanced T1 SPACE and DSA (AUC = 0.953) than PC MRV (AUC = 0.871). Intermodality agreement of enhanced T1 SPACE (r_k = 0.895 and weighted ĸ = 0.868) was better than PC MRV (r_k = 0.753 and weighted ĸ = 0.653) compared with DSA. Thirty-seven intrasinus filling defects were detected by contrast-enhanced T1 SPACE, while only twenty of them were detected on source imaging of PC MRV.

CONCLUSIONS

The contrast-enhanced T1 SPACE sequence was more sensitive and specific compared with PC MRV in assessing stenosis and detecting lesions in TSS patients. Accurate determination of the presence and extent of TSS using this technique might be useful in patient selection and guiding the treatment.

The Occipital Emissary Vein: A Possible Marker for Pseudotumor Cerebri

BACKGROUND AND PURPOSE

Transverse sinus stenosis can lead to pseudotumor cerebri syndrome by elevating the cerebral venous pressure. The occipital emissary vein is an inconstant emissary vein that connects the torcular herophili with the suboccipital veins of the external vertebral plexus. This retrospective study compares the prevalence and size of the occipital emissary vein in patients with pseudotumor cerebri syndrome with those in healthy control subjects to determine whether the occipital emissary vein could represent a marker of pseudotumor cerebri syndrome.

MATERIALS AND METHODS

The cranial venous system of 46 adult patients with pseudotumor cerebri syndrome (group 1) was studied on CT venography images and compared with a group of 92 consecutive adult patients without pseudotumor cerebri syndrome who underwent venous assessment with gadolinium-enhanced 3D-T1 MPRAGE sequences (group 2). The presence of an occipital emissary vein was assessed, and its proximal (intraosseous) and distal (extracranial) maximum diameters were measured and compared between the 2 groups. Seventeen patients who underwent transverse sinus stent placement had their occipital emissary vein diameters measured before and after stent placement.

RESULTS

Thirty of 46 (65%) patients in group 1 versus 29/92 (31.5%) patients in group 2 had an occipital emissary vein (P < .001). The average proximal and distal occipital emissary vein maximum diameters were significantly larger in group 1 (2.3 versus 1.6 mm, P <.005 and 3.3 versus 2.3 mm, P < .001). The average maximum diameters of the occipital emissary vein for patients who underwent transverse sinus stent placement were larger before stent placement than after stent placement: 2.6 versus 1.8 mm proximally (P < .06) and 3.7 versus 2.6 mm distally (P < .005).

CONCLUSIONS

Occipital emissary veins are more frequent and larger in patients with pseudotumor cerebri syndrome than in healthy subjects, a finding consistent with their role as collateral venous pathway in transverse sinus stenosis. A prominent occipital emissary vein is an imaging sign that should raise the suspicion of pseudotumor cerebri syndrome.

Long-term reactions to pulsatile tinnitus are marked by weakened short-range functional connectivity within a brain network in the right temporal lobe

BACKGROUND

There have been recent efforts to characterize brain functional activity features in patients with pulsatile tinnitus (PT). These efforts have revealed evidence of aberrant functional connectivity (FC) of the right middle temporal gyrus (MTG) in PT patients with prolonged disease duration.

PURPOSE

To assess the possible predictive effect of aberrant FC of MTG in PT patients with prolonged disease duration.

STUDY TYPE

Retrospective.

POPULATION

Thirty-four patients with recent-onset PT (RPTIN), 24 patients with long-term PT (LPTIN), and 35 age-, gender-, and education-matched healthy controls were enrolled.

FIELD STRENGTH/SEQUENCE

3.0T MRI system and echo-planar imaging (EPI) sequence, 3D brain volume imaging (BRAVO) sequence.

ASSESSMENT

Functional MRI data preprocessing was performed in Data Processing & Analysis for Brain Imaging (DPABI) and Statistical Parametric Mapping (SPM) 8. The FC analyses were conducted using the software REST.

STATISTICAL TESTS

One-way analysis of covariance was conducted between three groups with age and gender as covariates, and post-hoc analysis was used to identify the sources of group effects. Pearson's correlation analysis was conducted for the z-values of altered FC strength in the PT group and the clinical data.

RESULTS

Among hubs belonging to the executive control network, the default mode network (DMN), and limbic network, the strength of FC was mainly decreased in the patient groups compared with normal controls (P < 0.05). Relative to RPTIN patients and normal controls, LPTIN patients were further characterized by significantly decreased FC between several short-range brain regions adjacent to the seed (P < 0.05). Finally, disease duration was negatively correlated with decreased FC between the seed and right fusiform gyrus/parahippocampal gyrus, right inferior frontal gyrus, and right MTG (a brain area adjacent to the seed region).

DATA CONCLUSION

Long-term reactions to PT mainly involved weakened short-range FC, especially within a functional network in the right temporal lobe.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

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

PURPOSE

This aimed to evaluate the prevalence and extent of bilateral sigmoid sinus dehiscence (SSD) and to explore the presence of idiopathic intracranial hypertension (IIH) in patients with unilateral pulsatile tinnitus (PT) with CTA/V.

METHODS

Sixty PT patients (52 females; 40.4 ± 11.6 years [20-72]) who underwent CTA/V and 30 non-PT patients (27 females; 38.4 ± 14.7 years [12-62]) were enrolled in this study. The primary outcome measure was the radiographic presence of SSD. The index of transverse sinus stenosis (ITSS) was obtained by multiplying the stenosis scale values for each transverse sinus, and once was ≥ 4, the presence of IIH was suspected.

RESULTS

The prevalence and extent of SSD on symptomatic side (78%; maximum transverse diameter, MTD 0.49 ± 0.23; maximum vertical diameter, MVD 0.50 ± 0.26 cm) were significantly higher and larger than those on asymptomatic side (50%, P < 0.001; MTD 0.35 ± 0.18, P = 0.006; MVD 0.30 ± 0.15 cm, P < 0.001) in the study group and those (20%, P < 0.001; MTD 0.36 ± 0.18, P = 0.073; MVD 0.30 ± 0.22 cm, P < 0.048) in the control group. The presence of SSD showed significant correlation with both PT (logistic regression analysis, OR 4.167 [1.450-11.97]; P = 0.008) and suspected IIH (OR 16.25 [1.893-139.5]; P = 0.011).

CONCLUSION

In PT patients, SSD has a significant correlation with PT and a potential correlation with IIH.

Lateralization effects on functional connectivity of the auditory network in patients with unilateral pulsatile tinnitus as detected by functional MRI

Unilateral pulsatile tinnitus (PT) was proved to be a kind of disease with brain functional abnormalities within and beyond the auditory network (AN). However, changes in patterns of the lateralization effects of PT are yet to be established. Relationship between the AN and other brain networks in PT patients is also a scientific question need to be answered. In this study, we recruited 23 left-sided, 23 right-sided PT (LSPT, RSPT) patients and 23 normal controls (NC). We combined applied independent component analysis and seed-based functional connectivity (FC) analysis to investigate alteration feature of the FC of the AN by using resting-state functional magnetic resonance imaging (rs-fMRI). Compared with NC, LSPT patients demonstrated disconnected FC within the AN on both sides. Disrupted network integrity between AN and several brain functional networks, including executive control network, self-perceptual network and the limbic network, was also demonstrated in LSPT patient group bilaterally. In contrast, compared with NC, RSPT demonstrated decreased FC within the AN on the left side, but significant increased FC within the AN on the right side (symptomatic side). Enhanced FC between AN and executive control network, self-perceptual network and limbic network was also found mainly on the right side in patients with RSPT. Positive FC between the auditory network and the limbic network may be a reason to explain why RSPT patients are willing to be in the clinic. Briefly, LSPT exhibit disrupted network integrity in brain functional networks. But RSPT is featured by enhanced FC within AN and between networks, especially on the right (symptomatic) side. Corroboration of featured FC helps to reveal the pathophysiological changing process of the brain in patients with PT, providing imaging-based biomarker to distinguish PT from other kind of tinnitus.

Pressure Mapping and Hemodynamic Assessment of Intracranial Dural Sinuses and Dural Arteriovenous Fistulas with 4D Flow MRI

The feasibility of 4D flow MR imaging to visualize flow patterns and generate relative pressure maps in the dural venous sinus in healthy subjects (n = 60) and patients with dural arteriovenous fistulas (n = 7) was investigated. Dural venous drainage was classified based on torcular Herophili anatomy by using 4D flow MR imaging-derived angiograms and magnitude images. Subjects were scanned in a 3T clinical MR imaging system. 4D flow MR imaging enabled noninvasive characterization of dural sinus anatomy and mapping of relative pressure differences.