Association between idiopathic intracranial hypertension and sigmoid sinus dehiscence/diverticulum with pulsatile tinnitus: a retrospective imaging study

Flow Analysis of Central Venous Outflow Tract: A New Approach to Understanding Pulse-Synchronous Tinnitus

OBJECTIVE

Pulse-synchronous tinnitus (PST) has been linked to multiple anatomical variants of the central venous outflow tract (CVOT) including sigmoid sinus (SS) dehiscence and diverticulum. This study investigates flow turbulence, pressure, and wall shear stress along the CVOT and proposes a mechanism that results in SS dehiscence and PST.

STUDY DESIGN

Case series.

SETTING

Tertiary Academic Center.

METHODS

Venous models were reconstructed from computed tomography scans of 3 patients with unilateral PST. Two models for each patient are obtained: a symptomatic and contralateral asymptomatic side. A turbulent model-enabled commercial flow solver was used to simulate the pulsatile blood flow over the cardiac cycle through the models. Fluid flow through the transverse and SS junction was analyzed to observe the velocity, pressure, turbulent kinetic energy (TKE), and shear stress over a simulated cardiac cycle.

RESULTS

Fluid flow on the symptomatic side showed increased vorticity in the presence of an SS diverticulum. Higher TKE with periodicity following the cardiac cycle was observed on the symptomatic side, and a sharp increase was observed if SS diverticulum was present. Shear stress was highest near the narrowest segments of the vessel. Pressure was observed to be lower on the symptomatic side at the transverse-SS junction for all 3 patients.

CONCLUSION

Computational fluid dynamics modeling of blood flow through the CVOT in PST suggests that low pressure may be the cause of dehiscence, and tinnitus may result from periodic increases in TKE.

Exploring the utility of retinal optical coherence tomography as a biomarker for idiopathic intracranial hypertension: a systematic review

This study aimed to examine the existing literature that investigated the effectiveness of optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A) as a biomarker for idiopathic intracranial hypertension (IIH). Our search was conducted on January 17th, 2024, and included the databases, Medline, Scopus, Embase, Cochrane, Latin American and Caribbean Health Sciences Literature (LILACS), International Standard Randomized Controlled Trial Number (ISRCTN) registry, and the International Clinical Trials Registry Platform (ICTRP). Our final review included 84 articles. In 74 studies, OCT was utilized as the primary ocular imaging method, while OCT-A was employed in two studies including eight studies that utilized both modalities. Overall, the results indicated that IIH patients exhibited significant increases in retinal nerve fiber layer (RNFL) thickness, total retinal and macular thickness, optic nerve head volume, and height, optic disc diameter and area, rim area, and thickness compared to controls. A significant correlation was observed between cerebrospinal fluid (CSF) pressure and OCT parameters including RNFL thickness, total retinal thickness, macular thickness, optic nerve head volume, and optic nerve head height. Interventions aimed at lowering CSF pressure were associated with a substantial improvement in these parameters. Nevertheless, studies comparing peripapillary vessel density using OCT-A between IIH patients and controls yielded conflicting results. Our systematic review supports OCT as a powerful tool to accurately monitor retinal axonal and optic nerve head changes in patients with IIH. Future research is required to determine the utility of OCT-A in IIH.

Causes and outcomes of revision surgery in subjects with pulsatile tinnitus

INTRODUCTION

Once the underlying pathology has been identified, pulsatile tinnitus (PT) can be treated successfully with surgical or interventional management. However, some patients experience residual or recurrent symptoms following initially successful surgical treatment, and require revision surgery or additional procedures. Here, we report a case series of patients who had undergone revision surgery or interventional treatment, and suggest possible ways of minimizing the need for revision.

METHODS

Between January 2014 and March 2023, a total of seven subjects underwent revision surgery or interventional treatment for persistent or recurrent PT after initial surgical treatment. Demographic data, reasons for revision, and changes in symptoms before and after revision were analyzed retrospectively. Temporal bone computed tomographic angiography images were reviewed to identify the causes and reasons for revision.

RESULTS

Of the seven subjects, six underwent sigmoid sinus (SS) resurfacing/reshaping due to ipsilateral diverticulum (Div) or dehiscence (Deh), and one underwent jugular bulb (JB) resurfacing due to a high-riding JB with bony Deh. Of the five subjects who underwent revision SS surgery due to recurrent SS-Div or SS-Deh, three showed marked resolution of PT, while the other two showed partial improvement of the symptoms. One subject who underwent revision JB resurfacing, and another who underwent additional transarterial embolization for a concurrent ipsilateral dural arteriovenous fistula, reported marked improvement of PT.

DISCUSSION

The possibility of recurrence should be taken into account when performing surgical intervention in patients with PT. The likelihood of recurrence can be minimized through a comprehensive evaluation to identify possible multiple etiologies, and through the use of durable materials and appropriate surgical methods.

Study on the correlation between hemodynamic status of the transverse sinus-sigmoid sinus and the clinical efficacy of sigmoid sinus wall reconstruction

BACKGROUND AND PURPOSE

For patients with pulsatile tinnitus who have both transverse sinus stenosis and sigmoid sinus wall anomalies, sigmoid sinus wall reconstruction surgery is the first-choice treatment when the trans-stenotic pressure gradient less than 10 mmHg. However, not all patients are cured by surgery. We hypothesized the abnormal hemodynamics caused by transverse sinus stenosis is associated with the clinical efficacy of surgery.

METHODS

Eight pulsatile tinnitus patients treated with surgery were retrospectively reviewed (4 rehabilitated, 4 nonrehabilitated). All patients had radiologically diagnosed transverse sinus stenosis and sigmoid sinus wall anomalies. A numerical simulation of the hemodynamics of the transverse sinus-sigmoid sinus was performed using computational fluid dynamics technology. Changes in the blood flow patterns before and after surgery were observed. The blood flow velocity at the stenosis, vorticity of blood flow in the sigmoid sinus and wall pressure distribution in the sigmoid sinus wall anomalies area were compared.

RESULTS

The blood flow velocity in the stenosis (preoperative P = 0.04, postoperative P = 0.004) and vorticity in the sigmoid sinus (preoperative P = 0.02, postoperative P = 0.007) pre- and post-surgery were significantly higher in the non-rehabilitation group than in the rehabilitation group. No significant difference was found in the wall pressure distribution in the sigmoid sinus wall anomalies area (preoperative P = 0.12, postoperative P = 0.24).

CONCLUSIONS

There is a clear correlation between the abnormal hemodynamic status caused by transverse sinus stenosis and the clinical efficacy of surgery. The blood flow velocity at the stenosis and vorticity of blood flow in the sigmoid sinus are factors influencing the clinical efficacy of surgery.

Pediatric tinnitus: The role of neuroimaging

Tinnitus is defined as the perception of sound without an external source and can be categorized as either pulsatile or nonpulsatile (ie, continuous). A variety of etiologies have been reported to cause pediatric tinnitus, many with long-lasting implications due to hearing and concentration impairments. Therefore, imaging can be an essential part of the accurate and timely diagnosis of treatable etiologies. We describe neuroimaging findings in different etiologies of pediatric tinnitus. Etiologies of pulsatile tinnitus are frequently vascular in nature and include vascular loops, congenital vascular anomalies or variants, high riding jugular bulbs with or without a jugular bulb diverticulum, idiopathic intracranial hypertension, aneurysms, internal auditory canal hemangiomas, and petrous apex cephaloceles. Etiologies of continuous tinnitus frequently affect the middle/inner ear structures and include vestibular schwannomas, cholesteatomas, trauma, Chiari malformations, and labyrinthitis ossificans. CT and MR are often complementary modalities: CT is better suited to evaluate the integrity of the temporal osseous structures and MR is better suited to evaluate the vestibulocochlear nerve and to assess for the presence of any masses or malformations. Prompt diagnosis of the etiology of tinnitus in pediatric patients is important to avoid any potential long-term developmental impairments. In the approach to pediatric tinnitus, categorizing the symptoms as either pulsatile versus nonpulsatile and then being aware of the possible causes and imaging findings of either can assist both the clinician and the radiologist in making an expeditious diagnosis.

Neurosurgical Causes of Pulsatile Tinnitus: Contemporary Update

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

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.

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.

Effects of different morphologic abnormalities on hemodynamics in patients with venous pulsatile tinnitus: A four-dimensional flow magnetic resonance imaging study

The effects of morphologic abnormalities, including sigmoid sinus wall dehiscence (SSWD), transverse sinus stenosis (TSS), and sigmoid sinus diverticulum (SSD), on hemodynamics in venous pulsatile tinnitus (PT) patients have not been established. The aim of this study was to evaluate the effects of SSWD, TSS, and SSD on the hemodynamics of transverse‐sigmoid sinus in venous PT patients. This was a prospective study with 44 venous PT patients and 12 healthy controls. A 3 T/four‐dimensional (4D) flow magnetic resonance imaging with fast field echo was used. Computed tomography arteriography/venography was used to assess ipsilateral SSWD, TSS, and SSD. Maximum velocity (V_max), average velocity (V_avg), and average flow (Flow_avg) were measured. Blood flow patterns were independently assessed by three neuroradiologists. One‐way analysis of variance or Kruskal–Wallis test was also used. On the symptomatic side, all patients had SSWD, 33 patients had TSS, and 22 patients had SSD. Compared with healthy controls, patients with TSS, without TSS, with SSD, and without SSD all showed higher V_max (all p < 0.050), V_avg (all p < 0.050), and Flow_avg (all p < 0.050). Patients with TSS showed higher V_max (p < 0.050) and V_avg (p < 0.050) than those without TSS, and no significant difference in Flow_avg was found between the two groups (p = 0.408). No significant differences in V_max, V_avg, and Flow_avg were found between patients with and without SSD (all p = 1.000). Jet‐like flow in the stenosis and downstream of the stenosis was observed in all patients with TSS. Vortex in SSD was observed in 15 patients with SSD (68%). High blood velocity and flow may be characteristic markers of venous PT. SSWD may be a necessary condition for venous PT. TSS may further increase the blood velocity and form a jet‐like flow. SSD may be related to vortex formation but had no significant effect on blood velocity and flow.

Level of Evidence

2

Technical Efficacy Stage

3

Hydroacoustic analysis and extraluminal compression surgical insights of venous pulsatile tinnitus

OBJECTIVE

This study aimed to quantitatively and qualitatively evaluate the hydroacoustic changes from "presence" to "disappearance" of pulsatile tinnitus (PT) with the extraluminal compression surgical technique. The recent issues of concern pertaining to the hydroacoustic characteristics of sigmoid sinus wall anomalies and distal transverse sinus stenosis (dTSS) were discussed.

METHODS

This study was based on a retrospective case series. Seventy-seven patients with PT and transverse-sigmoid sinus enlargement with or without transverse-sigmoid sinus junction anomalies and transverse sinus stenosis (TSS) who had undergone extraluminal compression surgery under local anesthesia were included. Management of intractable intraoperative challenges and techniques for reversal extraluminal compression were introduced. Anatomical measurements, intraoperative color-coded Doppler ultrasonography, spectro-temporal analysis, and computational fluid dynamics were employed to analyze the hydroacoustic characteristics of PT.

RESULTS

The efficacy of the extraluminal compression technique was evident with the significant reduction in peak turbulent kinetic energy, vorticity, and mean pressure gradient at the transverse-sigmoid junction, resulting in over 20% reduction in PT amplitude. dTSS is a common finding in patients with PT exhibiting transverse-sigmoid sinus enlargement. Patients with dTSS presented with significant differences in hemodynamic characteristics as compared to those without. Linear regression analysis showed that the flow disturbance (turbulent kinetic energy and vorticity) was closely associated with the degree of dTSS, whereas the flow amplitude was not related to the degree or location of TSS. Low-pulsatory vortex flow at the transverse-sigmoid junction was visualized during an intraoperative color-coded Doppler examination, and the displayed low-frequency PT sound corresponded to the patients' subjective perception of PT.

CONCLUSION

(1) A reduction of over 20% of the flow-induced noise is the therapeutic goal of extraluminal compression technique. Since reductions in the magnitude of hemodynamic parameters, including turbulent kinetic energy, vorticity, and mean pressure gradient, render the flow-induced noise inaudible, besides sigmoid sinus wall anomalies, it is likely that PT develops from the aggregation of flow-based pathologies. (2) Although dTSS and diverticulum may greatly affect the hemodynamics at the transverse-sigmoid junction, in contrast to dehiscence, dTSS and diverticulum may not be the limiting factors for PT development.

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.

Extraluminal Sigmoid Sinus Angioplasty: A Pertinent Reconstructive Surgical Method Targeting Dural Sinus Hemodynamics to Resolve Pulsatile Tinnitus

OBJECTIVES

1) To provide information on the treatment of pulsatile tinnitus (PT) with transtemporal extraluminal sigmoid sinus angioplasty (ESSA); and 2) to discuss the current clinical management of PT.

STUDY DESIGN

This was a retrospective study.

SETTINGS

Multi-institutional tertiary university medical centers.

PATIENTS

Fifty-four PT patients with transverse-sigmoid sinus enlargement and prominent transverse-sigmoid junction with or without sigmoid sinus wall anomalies or transverse sinus anomalies.

INTERVENTION

All patients underwent ESSA under local anesthesia.

MAIN OUTCOME MEASURES

Intraoperative discoveries and surgical resolution of PT, morphology, and computational fluid dynamics.

RESULTS

Fifty-three of the 54 (98%) patients experienced a significant reduction in, or complete resolution of, PT after ESSA. No major surgical complications occurred, except for one case where we observed a full collapse of the sinus wall. On average, this surgery reduced the cross-sectional area at the transverse-sigmoid junction by 61.5%. Our intraoperative discoveries suggest that sigmoid sinus wall anomalies may not be a definitive cause of PT. The transverse-sigmoid sinus system was significantly larger (in term of both cross-sectional area and volume) on the ipsilesional side compared with the contralesional side. Following ESSA, the vascular wall pressure and vortex flow at the transverse-sigmoid junction decreased considerably, and the flow velocity and wall shear stress increased significantly.

CONCLUSION

ESSA is a highly effective surgical technique for PT patients with transverse-sigmoid sinus enlargement and prominent transverse-sigmoid junction, regardless of whether they also have sigmoid sinus wall or transverse sinus anomalies. A large transverse-sigmoid system with prominent transverse-sigmoid junction is a predisposing factor for PT, and only by improving patients' intrasinus hemodynamics could PT be resolved efficiently. In cases without complete obstruction of venous return, ESSA is safe. No postoperative complications related to neurological disorders were observed.

Treatment of pulsatile tinnitus caused by anomalies of the sigmoid sinus wall via combined internal and external sigmoid sinus wall reconstruction with 3D temporal bone CT guidance

PURPOSE

The present analysis aims to describe a surgical approach wherein pulsatile tinnitus (PT) arising due to sigmoid sinus wall anomalies (SSWA) can be treated via combination internal and external sigmoid sinus wall reconstruction. We further evaluated the utility of temporal bone 3D-CT imaging during both the pre- and post-operative assessments of all treated patients.

METHODS

Data pertaining to 11 patients that had undergone sigmoid sinus wall reconstruction were retrospectively analyzed. All of these patients underwent preoperative 3D-CT imaging assessment. These patients were additionally subjected to sigmoid sinus wall reconstruction via a combined internal and external layer approach. Postoperatively, all patients underwent a radiological assessment of auricular cartilage and autologous bone powered displacement. Patients were additionally asked about any subjective changes in PT or associated symptoms at follow-up time points.

RESULTS

SSWA in the 3D-CT imaging from these patients were all distinct. In 10/11 patients, PT fully resolved following reconstruction of the sinus wall. The remaining patients exhibited significant improvements in symptoms postoperatively, with PT fully resolving within a 1-month follow-up period. No patients suffered any major complications.

CONCLUSIONS

Temporal bone 3D-CT imaging allow for effective visualization of SSWA, enabling effective pre- and post-operative assessments of treated patients. A combined internal and external layer approach to sigmoid sinus wall reconstruction can be implemented safely and effectively, yielding high rates of satisfactory outcomes and achieving rigid reconstruction of this surface. As such, there is clear value in the consideration of this approach when treating individuals suffering from PT as a result of SSWA.

Sandwich technique for sigmoid sinus wall reconstruction for treatment of pulsatile tinnitus caused by sigmoid sinus diverticulum/dehiscence

Background: If the pulsatile tinnitus caused by sigmoid sinus diverticulum/dehiscence cannot be diagnosed and treated, it can lead to significant morbidity and mortality.Aim: To assess the sandwich surgical technique for sigmoid sinus wall reconstruction for the treatment of pulsatile tinnitus caused by sigmoid sinus diverticulum/dehiscence.Methods: A chart review was conducted with 17 patients suffering from pulsatile tinnitus caused by sigmoid sinus diverticulum/dehiscence who underwent sinus wall reconstruction surgery between January 2014 and July 2019.Results: Of the total patients studied, 16 were female, and one was male. The procedure was performed on the right ear of 15 patients and on the left ear of 2 patients. The pulsatile tinnitus disappeared in all patients following the sinus wall reconstruction surgery using the sandwich technique. The mean follow-up time was 25 months (a range of 8-55 months). In the follow-up period, no recurrence of pulsatile tinnitus was found. None of the patients experienced major complications such as thrombosis.Conclusions: The sandwich surgical technique for sinus wall reconstruction as a treatment for pulsatile tinnitus caused by sigmoid sinus diverticulum is safe and effective.

Pattern and severity of transverse sinus stenosis in patients with pulsatile tinnitus associated with sigmoid sinus wall anomalies

OBJECTIVE

Describe the location and severity of transverse sinus stenosis (TSS) in a consecutive series of patients with intraoperatively confirmed sigmoid sinus wall abnormalities (SSWA).

METHODS

A retrospective review of imaging studies from patients undergoing sinus wall reconstruction for pulsatile tinnitus associated with SSWA "was performed." Qualitative and quantitative analyses of the TSS, including the side, type, location, extent, and severity, were performed and compared with normal controls and historical controls with idiopathic intracranial hypertension (IIH).

RESULTS

Twenty-six of 36 subjects had adequate imaging data. The majority of subjects had some degree of bilateral TSS, and the majority of stenoses involved the distal transverse sinus. Subjects with diverticulum were significantly more likely than those with dehiscence to have ipsilateral distal TSS (16 of 16 vs. 4 of 10, P = 0.009). The mean minimum transverse sinus diameter, stenosis severity grade, and overall posterior venous sinus outflow were significantly worse in the subjects as compared to normal controls (P = 0.002), although not as severe as the comparable values in historical controls with IIH (P < 0.003).

CONCLUSION

Subjects with SSWA have a high incidence of TSS, with patterns differing between those with dehiscence and diverticulum. Severity of TSS and overall posterior fossa venous outflow are worse as compared to normal controls but not as severe as in subjects with IIH. These findings have implications for the pathophysiology and management of SSWA.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1028-1033, 2020.

Pulsatile versus non-pulsatile tinnitus in idiopathic intracranial hypertension

INTRODUCTION

Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension (IIH) that can have a profound effect on quality of life. We aim to determine tinnitus symptom response after dural venous sinus stenting (DVSS) or CSF diversion with a shunt, in patients with both pulsatile (PT) and non-pulsatile tinnitus (NPT).

METHODS

Single-centre cohort of IIH patients (2006-2016) who underwent 24-h ICP monitoring (ICPM). An un-paired t test compared ICP and pulse amplitude (PA) values in IIH patients with PT vs. NPT.

RESULTS

We identified 59 patients with IIH (56 F:3 M), mean age 32.5 ± 9.49 years, 14 of whom suffered from tinnitus. Of these 14, seven reported PT and seven reported NPT. Patients with tinnitus had a mean 24-h ICP and PA of 9.09 ± 5.25 mmHg and 6.05 ± 1.07 mmHg respectively. All 7 patients with PT showed symptom improvement or resolution after DVSS (n = 4), secondary DVSS (n = 2) or shunting (n = 1). In contrast, of the 7 with NPT, only 1 improved post intervention (DVSS), despite 2 patients having shunts and 5 having DVSS.

CONCLUSIONS

NPT and PT were equally as common in our group of IIH patients. DVSS appears to be an effective management option for IIH patients with a clear history of pulsatile tinnitus. However, non-pulsatile tinnitus was more persistent and did not respond well to either DVSS or CSF diversion.

Clipping of sigmoid sinus diverticulum: how I do it

OBJECTIVE

To report two cases of transmastoid clipping of a sigmoid sinus diverticulum.

METHODS

Two patients with pulsatile tinnitus resulting from a sigmoid sinus diverticulum underwent clipping at the diverticulum neck using intra-operative Doppler ultrasonography.

RESULTS

At six months' follow up, both patients reported complete resolution of pulsatile tinnitus with no complications.

CONCLUSION

Transmastoid clipping of a sigmoid sinus diverticulum can be a safe and effective method of managing pulsatile tinnitus resulting from a sigmoid sinus diverticulum.

Evaluation and treatment of pulsatile tinnitus associated with sigmoid sinus wall anomalies

OBJECTIVE

Describe clinical and radiographic features of sigmoid sinus wall anomalies (SSWA) associated with pulsatile tinnitus (PT) and determine factors predictive of response to surgery.

METHODS

Preoperative diagnostic imaging and treatment response were reviewed after surgical repair of 40 ears among 38 consecutive patients presenting with PT associated with SSWA who underwent transtemporal sinus wall reconstruction.

RESULTS

Twenty-three ears had isolated sigmoid sinus dehiscence, and 17 had diverticulum. The rates of transverse sinus stenosis (TSS) and empty sella, 66% and 32% respectively, were significantly higher than in historical controls (P = 0.02 and 0.001). Thirty-six out of 40 subjects (90%) had complete resolution of their PT following surgery, including all those with a diverticulum. For subjects with dehiscence alone without diverticulum, a favorable response to surgery was strongly associated with the presence of TSS (P = 0.01) and empty sella (P = 0.02).

CONCLUSION

Sigmoid sinus diverticulum and dehiscence are a clinically important cause of PT. Women of childbearing age with an elevated body mass index (BMI) are commonly affected, and there is a high rate of associated TSS and empty sella. Transtemporal sinus wall reconstruction has a high rate of success in appropriately selected patients. Patients with isolated sinus wall dehiscence without diverticulum, TSS, or empty sella are less likely to respond to transtemporal sinus wall reconstruction. These data imply a multifactorial cause of PT in at least some patients with SSWA.

LEVEL OF EVIDENCE

4 Laryngoscope, 128:S1-S13, 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.

Utility of Intracranial Pressure Monitoring for Diagnosis of Idiopathic Intracranial Hypertension in the Absence of Papilledema

BACKGROUND

Idiopathic intracranial hypertension (IIH) is characterized by headaches, visual obscurations, and papilledema, and the diagnosis involves lumbar puncture (LP) with an elevated opening pressure (OP) ≥20 cm H₂0. When papilledema is absent, the diagnosis becomes less clear. Some physicians have argued that the absence of papilledema rules out IIH, whereas others maintain that elevated OP is sufficient for diagnosis.

METHODS

The authors performed a single-institution 4-year retrospective analysis of patients who underwent invasive intracranial pressure (ICP) monitoring for presumed IIH.

RESULTS

A total of 22 patients were reviewed, and 13 had classic symptoms of IIH, documented elevated OP, and absence of papilledema; 5/13 (38%) patients had proven intracranial hypertension as shown by invasive ICP monitoring, whereas 8/13 (62%) had normal ICP.

CONCLUSIONS

With the use of current diagnostic algorithms of clinical presentation and elevated OP, over half of patients without papilledema in our series would be falsely diagnosed with IIH, which could result in unnecessary medical and surgical intervention. Thus, elevated OP as determined by LP is insufficient to diagnose IIH. On the other hand, the absence of papilledema does not rule out intracranial hypertension.

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

BACKGROUND AND PURPOSE

Pulsatile tinnitus is experienced by most patients with idiopathic intracranial hypertension. The pathophysiology remains uncertain; however, transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence have been proposed as potential etiologies. We aimed to determine whether the prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence was increased in patients with idiopathic intracranial hypertension and pulsatile tinnitus relative to those without pulsatile tinnitus and a control group.

MATERIALS AND METHODS

CT vascular studies of patients with idiopathic intracranial hypertension with pulsatile tinnitus (n = 42), without pulsatile tinnitus (n = 37), and controls (n = 75) were independently reviewed for the presence of severe transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence according to published criteria. The prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence in patients with idiopathic intracranial hypertension with pulsatile tinnitus was compared with that in the nonpulsatile tinnitus idiopathic intracranial hypertension group and the control group. Further comparisons included differing degrees of transverse sinus stenosis (50% and 75%), laterality of transverse sinus stenosis/sigmoid sinus diverticulum/dehiscence, and ipsilateral transverse sinus stenosis combined with sigmoid sinus diverticulum/dehiscence.

RESULTS

Severe bilateral transverse sinus stenoses were more frequent in patients with idiopathic intracranial hypertension than in controls (P < .001), but there was no significant association between transverse sinus stenosis and pulsatile tinnitus within the idiopathic intracranial hypertension group. Sigmoid sinus dehiscence (right- or left-sided) was also more common in patients with idiopathic intracranial hypertension compared with controls (P = .01), but there was no significant association with pulsatile tinnitus within the idiopathic intracranial hypertension group.

CONCLUSIONS

While our data corroborate previous studies demonstrating increased prevalence of sigmoid sinus diverticulum/dehiscence and transverse sinus stenosis in idiopathic intracranial hypertension, we did not establish an increased prevalence in patients with idiopathic intracranial hypertension with pulsatile tinnitus compared with those without. It is therefore unlikely that these entities represent a direct structural correlate of pulsatile tinnitus in patients with idiopathic intracranial hypertension.

Idiopathic intracranial hypertension: Contemporary review and implications for the otolaryngologist

OBJECTIVES

1) Review controversies pertaining to the pathophysiology, diagnosis, and treatment of idiopathic intracranial hypertension. 2) Discuss the evolving role of otolaryngologists in managing this disease and related disorders.

DATA SOURCES

Primary literature review, Centers for Disease Control and Prevention website, International Classification of Headache Disorders, Second Edition.

METHODS

A comprehensive review of the primary literature was performed from 1990 to 2016 utilizing keywords idiopathic intracranial hypertension, pseudotumor cerebri, benign intracranial hypertension, spontaneous cerebrospinal fluid leak, and encephalocele. Articles were included at the discretion of the authors based on novel and/or historical contributions to the literature.

RESULTS

The incidence of idiopathic intracranial hypertension is increasing along with the obesity epidemic. Undiagnosed patients may present to otolaryngologists with pulsatile tinnitus, dizziness, sleep apnea, and spontaneous cerebrospinal fluid leaks. Although diagnosis is predicated upon imaging findings and lumbar puncture, radiographic signs including empty sella, optic nerve dilation, and globe flattening may suggest the diagnosis. The most effective intervention is weight loss combined with acetazolamide. Surgery is reserved for severe or refractory symptoms and can be highly morbid. Otolaryngologists are increasingly responsible for managing a number of secondary disorders including cerebrospinal fluid rhinorrhea and otorrhea. Failure to manage intracranial hypertension may lead to adverse surgical outcomes.

CONCLUSIONS

The knowledge base for idiopathic intracranial hypertension has greatly expanded over the past 25 years. This disease is associated with a number of conditions directly relevant to otolaryngologists. A keen understanding of this disorder and its management may optimize outcomes in a growing number of patients. Laryngoscope, 128:248-256, 2018.

An update on idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is still a grey area in the knowledge of the aetiology, diagnosis and management of neurosurgical diseases. The definition of IIH has been reviewed over time and many hypotheses have been expressed as cause of the disease. The literature supplies very little evidence-based information to guide our decision-making process when it comes to treat the disease. In this review we sum up the latest information regarding the aetiology and therapy of IIH. Additionally, we make an attempt to unify the diagnostic criteria of Dandy, Friedman and Wall established from 1937 to date.

METHOD

In this narrative review, we attempt to update the current standpoint to IIH, evaluate the input until now and consider future directions for research. The vast majority of the literature consisted of cohort studies, case control studies, systematic reviews and other narrative reviews.

RESULTS

Pathophysiology: The incidence of IIH is steadily increasing. Several pathophysiological theories have been proposed in the literature based on the flow of cerebrospinal fluid.

DIAGNOSIS

We attempt to fuse all the three diagnostic approaches published in the literature that detect IIH, while preserving the individual characteristics of each approach.

TREATMENT

Based on evidence-based trials, the current use of acetazolamide in comparison with placebo or with topiramate has been evaluated. In the interventions' field, there seems to be a consonance about the alarming symptoms and what the most suitable operation is in each case. There is some disagreement about the indications for venous sinus transversus stenting and its risk/benefit ratio.

CONCLUSIONS

Until now there is no class I guideline to which our decision-making can be based on for the management of IIH. A lack of systematic reviews and randomised control trials has been noted. If we focused our research on that, we could develop a standardised treatment protocol.

Sigmoid Sinus Wall Reconstruction for Pulsatile Tinnitus Caused by Sigmoid Sinus Wall Dehiscence: A Single-Center Experience

OBJECTIVE

To evaluate clinical characteristics and present surgical outcomes of PT caused by sigmoid sinus wall dehiscence (SSWD).

METHODS

This study retrospectively reviewed 34 patients with PT who were diagnosed with SSWD in our institution between December 2008 and July 2013. Among them, 27 patients underwent sigmoid sinus wall reconstruction (surgery group) and 7 patients refused surgery (non-surgery group). Preoperative data were obtained from the patients' medical records. All patients were followed up regularly for at least 25 months. Preoperative and postoperative computed tomography angiography (CTA) images were compared. Student's t-tests were used to compare age, body mass index (BMI) and preoperative Tinnitus Handicap Inventory (THI) scores between the surgery and the non-surgery groups and to compare pre- and follow-up THI scores.

RESULTS

There was no significant difference in age, body mass index, or preoperative THI scores between groups. Following surgery, 14 patients had complete resolution, 5 had partial resolution, 7 experienced no change and PT was aggravated in 1 patient. The difference between preoperative and postoperative THI scores was significant. No severe complications were found postoperatively. Comparison of the preoperative and postoperative CTA images revealed that remnant unrepaired dehiscences were the cause of unsatisfactory outcomes following surgery. In the non-surgery group, PT remained largely unchanged.

CONCLUSIONS

Sigmoid sinus wall reconstruction is an effective and safe treatment for PT caused by SSWD. It is imperative that all regions of the dehiscence are sufficiently exposed and resurfaced during surgery.

Association between the extent of sigmoid sinus dehiscence and an occurrence of pulsatile tinnitus: a retrospective imaging study

AIM

To assess the extent of sigmoid sinus dehiscence (SSD) on high-resolution computed tomography venography (HRCTV) or high-resolution computed tomography (HRCT) images in pulsatile tinnitus (PT) and non-PT groups to determine whether there is an association between the extent of SSD and occurrence of PT.

MATERIALS AND METHODS

Twenty-eight SSD patients with ipsilateral PT and 28 age- and gender-matched SSD patients without PT who underwent HRCTV or HRCT were enrolled in this study and categorised into two groups: "PT group" and "non-PT group". The extent of SSD in each group was calculated and compared.

RESULTS

The largest transverse diameter and largest vertical diameter of SSD in the PT group were 6.21±1.7 and 6.15±2.19 mm, respectively. The largest transverse diameter and largest vertical diameter of SSD in the non-PT group were 3.06±1.38 and 2.51±1.03 mm, respectively. The extent of SSD was statistically different between the two groups (p<0.001; p<0.001).

CONCLUSIONS

As a cause of PT, SSD can also occur in individuals without PT symptoms. Preliminary findings suggest that there may be a potential correlation between the extent of SSD and an occurrence of PT.

Obesity related complications in surgery

PURPOSE OF REVIEW

This article aims to review relevant implications of obesity and associated comorbid conditions for the otology and neurotology surgical subspecialties.

RECENT FINDINGS

Both the incidence and prevalence of obesity are rising worldwide. This condition, along with its many associated comorbidities, can adversely affect the perioperative management of patients undergoing otologic and neurotologic procedures. Preoperative assessment of the cardiopulmonary system and airway are imperative as compromise of either may lead to death. Physiologic changes found in patients with obesity have been shown to predispose to hemodynamic instability, intolerance of hypoxia, bleeding, thrombo-embolism, poor wound healing, and decreased drug clearance. An 'obesity paradox' may exist in which patients who are overweight or obese may have less perioperative morbidity and mortality. Patients who are underweight or morbidly obese seem to have worse surgical outcomes. Obesity has been associated with intracranial hypertension, risk of cerebrospinal fluid (CSF) leak recurrence, and skull base erosion leading to multiple pathologic conditions. These include spontaneous CSF otorrhea, semicircular canal dehiscence syndrome, and sigmoid sinus diverticulum.

SUMMARY

The obese habitus and physiology significantly affects patients undergoing otologic and neurologic surgeries. A thorough understanding of this condition is paramount to successful outcomes.

The relationship between tinnitus and vascular anomalies on temporal bone CT scan: a retrospective case control study

INTRODUCTION

Tinnitus is a common symptom in which etiology is unclear in a group of patients. Some of anatomic or vascular variations diagnosed on temporal bone computed tomography (CT) has been known to cause tinnitus particulary pulsatile form. Therefore significance of these anatomic variations has not been validated in patients with nonpulsatile tinnitus. The aim of this study is to ascertain several anatomic variations previously attributed to pulsatile tinnitus in nonpulsatile tinnitus patients. And secondly to assess the relationship between the amount of sigmoid sinus bulging and mastoid emissary vein (MEV), enlargement of those was not evaluated before in tinnitus patients.

METHODS

Retrospectively, temporal bone CT scans of 70 patients with an existing complaint of tinnitus with unexplained etiology were enrolled. As a control group, 70 patients were selected from paranasal sinus CT scans without any otological or clinical findings.

RESULTS

The type of tinnitus was subjective and nonpulsatile in the overall group. The diameters of enlarged MEV on the left side were significantly higher in the tinnitus group. Carotid canal dehiscence and high riding jugular bulb were significantly higher in the tinnitus patients. Petrous bone pneumatization was significantly lower in the tinnitus patients than in the control group.

CONCLUSIONS

In patients who complained of subjective nonpulsatile tinnitus with unknown etiology, some temporal bone vascular variations, including high riding jugular bulb, dehiscent carotid canal, left-sided MEV enlargement, and petrous bone pneumatization, seemed to have an association with tinnitus. Further studies comparing all these entities between pulsatile and nonpulsatile groups and healthy controls should be undertaken.