A high jugular bulb and poor development of perivestibular aqueductal air cells are not the cause of endolymphatic hydrops in patients with Ménière’s disease

Comparison of radiological abnormalities between the jugular bulb and the vestibular aqueduct in patients with Ménière's disease

Objective

Anatomical variations of the inner ear may contribute to the development of Ménière's disease (MD), which is a complex inner ear disorder histopathologically characterized by idiopathic endolymphatic hydrops (ELH). Abnormalities of the vestibular aqueduct (VA) and the jugular bulb (JB) have been suggested as predisposing factors. Yet, few studies have investigated the correlation between JB abnormalities and VA variations as well as its clinical relevance in these patients. In this retrospective study, we investigated the differences in the incidence of radiological abnormalities of the VA and JB in patients with definite MD.

Methods

Anatomical variations of JB and VA were evaluated based on high-resolution CT (HRCT) in a series of 103 patients with MD (93 unilateral cases and 10 bilateral cases). JB-related indices included JB anteroposterior and mediolateral diameter, JB height, JB type regarding to Manjila classification system, and incidences of JB diverticulum (JBD), JB related inner ear dehiscence (JBID), and inner ear adjacent JB (IAJB). VA-related indices included CT-VA visibility, CT-VA morphology (funnel, tubular, filiform, hollow, and obliterated-shaped type), and peri-VA pneumatization. Radiological indices were compared between MD ears and control ears.

Results

Radiological JB abnormalities were comparable between MD ears and control ears. As for VA-related indices, the CT-VA visibility was lower in MD ears than in control ears (p = 0.004). The distribution of CT-VA morphology was significantly different between MD and control ears (p = 0.013), with a higher proportion of obliterated-shaped type in MD ears (22.1%) than in control ears (6.6%).

Conclusion

Compared with JB abnormalities, the anatomical variations of VA are more likely to be an anatomically predisposing factor for MD.

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.

Cross-sectional Area of the Superior Petrosal Sinus is Reduced in Patients with Significant Endolymphatic Hydrops

Purpose: To evaluate the relationship between the size of the venous structures related to the inner ear and the degree of endolymphatic hydrops (EH).

Methods: Thirty-four patients with a suspicion of EH underwent whole brain MR imaging including the inner ear. Images were obtained pre- and post-administration, and at 4 and 24 hours after the intravenous administration of a gadolinium-based contrast agent (IV-GBCA). The cross-sectional areas (CSA) of the internal jugular vein (IJV), superior petrosal sinus (SPS), and inferior petrosal sinus (IPS) were measured on the magnetization prepared rapid acquisition of gradient echo (MPRAGE) images obtained immediately after the IV-GBCA. The grade of EH was determined on the hybrid of reversed image of positive endolymph signal and native image of positive perilymph signal (HYDROPS) images obtained at 4 hours after IV-GBCA as no, mild, and significant EH according to the previously proposed grading system for the cochlea and vestibule, respectively. The ipsilateral CSA was compared between groups with each level of EH grade. P < 0.05 was considered statistically significant.

Results: There were no statistically significant differences between EH grades for the CSA of the IJV or that of the IPS in either the cochlea or the vestibule. The CSA of the SPS in the groups with significant EH was significantly smaller than that in the group with no EH, for both the cochlea (P < 0.01) and the vestibule (P < 0.05). In an ROC analysis to predict significant EH, the cut-off CSA value in the SPS was 3.905 mm² for the cochlea (AUC: 0.8762, 95% confidence interval [CI]: 0.7952‒0.9572) and 3.805 mm² for the vestibule (AUC: 0.7727, 95% CI: 0.6539‒0.8916).

Conclusion: In the ears with significant EH in the cochlea or vestibule, the CSA of the ipsilateral SPS was smaller than in the ears without EH.

Value of CT and three-dimensional reconstruction revealing specific radiological signs for screening causative high jugular bulb in patients with Meniere's disease

Background

The aim of the present study was to investigate the pathological features of vestibular aqueduct (VA) related high jugular bulb (HJB) and explore the possible cause-consequence relation between HJB and endolymphatic hydrops (EH), and the potential specific radiological signs for screening causative HJB in Meniere’s disease (MD).

Methods

High-resolution computed tomography (HRCT) and three-dimensional reconstruction (3DRC) were used to detect the anatomical variables associated with VA and jugular bulb (JB) in hydropic and non-hydropic ears. The presence or absence of EH in the inner ear was determined by gadopentetate dimeglumine-enhanced magnetic resonance imaging. The presence of different types of HJB, the anatomical variables of the VA and JB and the three types of anatomical relationship between the VA and HJB were compared between the hydropic and non-hydropic ears using the χ² or Fisher’s exact tests. P < 0.05 was considered to indicate a statistically significant difference.

Results

JB was classified as: Type 1, no bulb; type 2, below the inferior margin of the posterior semicircular canal (PSCC); type 3, between the inferior margin of the PSCC and the inferior margin of the internal auditory canal (IAC); type 4, above the inferior margin of the IAC. There were no significant differences in the presence of types 1, 2 and 3 JB between two groups. The presence of type 4 JB, average height of the JB and prevalence of the non-visualization of the VA in CT scans showed significant differences between two groups. The morphological pattern between the JB and VA revealing by 3DRC was classified as: Type I, the JB was not in contact with the VA; type II, the JB was in contact with the VA, but the latter was intact without obstruction; type III, the VA was obliterated by HJB encroachment. There were no significant differences in the presence of type I and II between two groups. Type III was identified in 5 hydropic ears but no non-hydropic ears, with a significant difference observed between the two groups.

Conclusion

The present results showed that JB height and non-visualization of the VA on Pöschl’s plane could render patients susceptible to the development of EH. A jugular bulb reaching above the inferior margin of the IAC (type 4 JB) could obstruct VA, resulting in EH in a few isolated patients with MD. VA obliteration revealed by 3DRC, as a specific radiological sign, may have the potential for screening causative HJB in MD.

Different medications for the treatment of Ménière's disease by intratympanic injection: A systematic review and network meta-analysis

BACKGROUND

It is generally accepted that intratympanic injection provides an effective approach to manage severe vertigo in Ménière's disease. Although there are several medications available, that which is the most effective is still subject to debate.

OBJECTIVE

To assess the effectiveness and safety of the different medications used in the treatment of Ménière's disease by intratympanic injection using a network meta-analysis.

METHODS

PubMed, EMBASE, CINAHL and CENTRAL were searched. Only randomised controlled trials that compared the effectiveness of medications used for intratympanic injection to treat Ménière's disease with each other or a placebo were included. The primary outcome assessed was the effectiveness of medication in the management of vertigo symptoms. The effectiveness was expressed in terms of risk ratio (RR) with a 95% credible interval (CrI) for individual studies analysed. Network meta-analyses were performed by Stata version 15.0 using the network package.

RESULTS

Nine studies involving 314 patients treated with five different medications were included in the present analysis. A number of injections given varied from 1 to 10 and the follow-up time from 3 to 28 months. When compared to each other or to a placebo, Gentamicin was found to be the most efficacious medication, followed by Methylprednisolone, Latanoprost, Dexamethasone and Ganciclovir in order of effectiveness. However, no significant difference in efficacy was found between Gentamicin and Methylprednisolone when outcomes from studies with a follow-up time equal to or more than 24 months were analysed. It was not possible to conduct subgroup and sensitivity analysis because of the limited number of studies that were included.

CONCLUSION

All medications are more effective than a placebo in the treatment of Ménière's disease by intratympanic injection. According to the SUCRA, Gentamicin ranked the most effective, with Gentamicin and Methylprednisolone equally effective in the long-term effect. When the potential risk of hearing loss induced by Gentamicin is taken into consideration, Methylprednisolone may be the best choice for the treatment of Ménière's disease by intratympanic injection.