Medial High Jugular Bulb

The relationship between jugular bulb position and jugular bulb related inner ear dehiscence: a retrospective analysis

OBJECTIVE

High jugular bulb (HJB) can erode inner ear structures creating a jugular bulb related inner ear dehiscence (JBID). The aim of this study was to analyze the relationship between the position of jugular bulb (JB) and JBID using high-resolution computed tomography (HRCT).

MATERIAL AND METHODS

In this retrospective study HRCT images of 552 ears of 276 patients with hearing loss, otogenic vertigo, tinnitus or idiopathic peripheral facial nerve paralysis were analyzed. HJB type-1 was defined when JB dome reached above the inferior part of the round window, but was below the inferior edge of the internal acoustic meatus (IAM). HJB type-2 was defined when the dome of JB was higher than the inferior edge of IAM. The frequencies and types of HJB were evaluated. JBID for each HJB type was determined. Frequencies of JBID eroding the vestibular aqueduct (VA), the cochlear aqueduct and the posterior semicircular canal were examined.

RESULTS

HJB type-1 and HJB type-2 were found in 19% (105/552) and in 15.8% (87/552) of studied ears. JBID showed to be in 3.8% (21/552) of all ears. 90.5% (19/21) of JBID revealed eroding of VA. Jugular bulb related cochlear aqueduct dehiscence and jugular bulb related posterior semicircular canal dehiscence were found in one ear each. The frequency of jugular bulb related vestibular aqueduct dehiscence (JBVAD) in patients with HJB reaching above IAM was higher than in patients with HJB lower than IAM.

CONCLUSIONS

HJB is common, but JBID is rare. JBID prevalently erodes VA. HJB rising above IAM is most at risk to show JBVAD.

High and dehiscent jugular bulb: clear and present danger during middle ear surgery

PURPOSE

Internal jugular vein is anatomic continuation of cranial dural sinuses in the neck region. During the course of skull base the first enlarged segment of jugular vein is described as jugular bulb. The aim of this study is to evaluate the jugular bulb abnormalities and define the risk of high and dehiscent jugular bulb injury during middle ear surgery.

METHODS

This is a retrospective radiologic study of 1,010 patients (2,020 temporal bones) with various ear symptoms who had high resolution temporal bone computed tomography scans between 2007 and 2011.

RESULTS

High jugular bulb was seen in 308 (15.2 %) temporal bones. Jugular bulb dehiscence was encountered in 153 (7.5 %) temporal bones. High jugular bulb and jugular bulb dehiscence were more common in the right ears and females. Forty-one (2 %) temporal bones revealed high and dehiscent jugular bulb which can be vulnerable during middle ear surgery. High and dehiscent jugular bulb was more common in the right ears and males. Male predominance becomes more significant in the left ears. Of the 308 temporal bones with high jugular bulb, 87 (28.2 %) also had coexisting carotid canal dehiscence.

CONCLUSION

High and dehiscent jugular bulb is an important anatomic variation that can result in catastrophic outcomes during middle ear surgery. Our series show that 2 % of patients can be considered in the "high-risk" group. Precise assessment of the preoperative computed tomography scans by both the radiologist and the ENT surgeon is of utmost importance. Preoperative awareness will minimize morbidity and mortality.

Prevalence of Jugular Bulb Abnormalities and Resultant Inner Ear Dehiscence

Objective

Jugular bulb abnormalities (JBA), including high-riding jugular bulb (HRJB) and jugular bulb diverticulum (JBD), can erode into the inner ear. In this study, the authors investigate the prevalence and consequences of JBA and their erosion into inner ear structures using temporal bone histopathology and computed tomography (CT).

Study Design

Cross-sectional study of temporal bone histopathology and radiology.

Setting

Academic medical center.

Subjects and Methods

In total, 1579 temporal bone specimens and 100 CT of the temporal bones (200 ears) were examined for JBA and any associated dehiscence of inner ear structures. Temporal bone specimens were examined for histological consequences of inner ear erosion. Jugular bulb dimensions were measured on axial CT scans and compared across groups. Accompanying demographic and clinical information were reviewed.

Results

High jugular bulbs were noted in 8.2% (130/1579) of temporal bone specimens and in 8.5% (17/200) of temporal bone CT. The prevalence of JBA increases during the first 4 decades of life and stabilizes thereafter. High-riding jugular bulbs eroded inner ear structures such as the vestibular aqueduct, vertical facial nerve, or posterior semicircular canal in 2.8% (44/1579) of cases histologically and 1.5% (3/200) radiologically. In most, jugular bulb–mediated inner ear dehiscence was clinically and radiologically silent.

Conclusion

Jugular bulb abnormalities are common. They are present in 10% to 15% individuals and are primarily acquired by the fourth decade of life. In 1% to 3% of cases, the HRJB erodes into the inner ear and most frequently involves the vestibular aqueduct.

Ménière's disease in children aged 4-7 years

This is a retrospective review of clinical data and audiovestibular test results from four children in whom symptoms suggesting Ménière's disease started at 4-7 years of age. The four patients all had spontaneous recurrent attacks of (spinning) vertigo and fluctuating low frequency sensorineural hearing loss from an early age, suggesting a diagnosis of definite Ménière's disease. Presumably, due to age-related inability to communicate auditory symptoms, the children did not initially meet requirements for a diagnosis of Ménière's disease. However, by 8 years of age, all four children reported tinnitus and/or fullness in the affected ear and, thus, met the AAO criteria for Ménière's disease. Even if information on subjective auditory symptoms is missing, it is reasonable to consider young children with idiopathic spontaneous recurrent attacks of vertigo in whom audiograms reveals fluctuating low frequency hearing loss to have Ménière's disease. This report is a reminder that Ménière's disease may also occur in young children.

The relationship between jugular bulb-vestibular aqueduct dehiscence and hearing loss in pediatric patients

OBJECTIVE

To determine the prevalence of jugular bulb and vestibular aqueduct dehiscence (JBVAD) in pediatric patients undergoing temporal bone computed tomography (CT) scans and to assess the relationship between JBVAD and hearing loss.

STUDY DESIGN

Cross-sectional study with chart review.

SETTING

Tertiary academic medical center.

SUBJECTS AND METHODS

All patients 18 years of age or younger who had undergone temporal bone CT scans and audiometric testing between 2004 and 2009 were retrospectively reviewed. JBVAD was determined by blinded review of CT images. Hearing loss was determined by review of audiometric data and was correlated with imaging findings.

RESULTS

CT images and audiometric data were available for review in 927 patients (1854 ears). Overall prevalence of JBVAD was 8.6%, with a prevalence of 6.6% in right ears and 3.6% in left ears. JBVAD was present in 8.3% and 7.1% of patients with and without sensorineural or mixed hearing loss, respectively (95% confidence interval [CI], -2.3% to 4.6%; P = .51). Similarly, JBVAD was present in 5.5% of ears with and 4.6% of ears without sensorineural or mixed hearing loss (95% CI, -1.1% to 2.9%; P = .37).

CONCLUSION

The prevalence of JBVAD is 8.6% in pediatric patients undergoing temporal bone CT scans, 65% of which occur in the right ear. We were unable to identify any relationship between JBVAD and hearing loss. A major contribution to pediatric sensorineural hearing loss from JBVAD is therefore extremely unlikely.

Clinical spectrum of patients with erosion of the inner ear by jugular bulb abnormalities

OBJECTIVES/HYPOTHESIS

Anatomic variants of the jugular bulb (JB) are common; however, abnormalities such as large high riding JB and JB diverticulum (JBD) are uncommon. Rarely, the abnormal JB may erode into the inner ear. The goal of our study is to report a large series of patients with symptomatic JB erosion into the inner ear.

STUDY DESIGN

Retrospective review in an academic medical center.

METHODS

Eleven patients with JB abnormality eroding into the inner ear were identified on computed tomography (CT) scan of the temporal bone.

RESULTS

Age at presentation was from 5 years to 82 years with six males and five females. The large JB or JBD eroded into the vestibular aqueduct (n = 9) or the posterior semicircular canal (n = 4). The official radiology report usually identified the JB abnormality; however, erosion into these structures by the JB was not mentioned in all but one case. All patients were symptomatic with five having conductive hearing loss (CHL) and three complaining of pulsatile tinnitus. Those with pulsatile tinnitus and four of five with CHL had erosion into the vestibular aqueduct. Vestibular evoked myogenic potential (VEMP) findings in three of six patients were consistent with dehiscence of the inner ear.

CONCLUSIONS

High riding large JB or JBD can erode into the inner ear and may be associated with CHL and/or pulsatile tinnitus. CT scan is diagnostic and should be examined specifically for these lesions. As patients with pulsatile tinnitus may initially undergo a magnetic resonance imaging scan, identification of JB abnormality should prompt CT scan or VEMP testing to evaluate for inner ear erosion.

Pathology and pathophysiology of Meniere's disease

Histopathologic study of the human temporal bone entails microscopic examination and analysis of a series of histologic sections. This is currently the most effective method for observing the pathologic conditions of MD by examining the entire inner ear. Complete temporal bone histopathology cannot be replaced by either clinical pathologic study of small biopsy specimens obtained during surgery, or experimental animal studies that can create endolymphatic hydrops but not create MD. We believe that the histopathologic findings together with clinical information on MD is valuable in enhancing our understanding of the pathophysiology of the inner ear in MD. For example, a hypoplastic VA and ES in MD seem to indicate that there may be congenital predisposing factors in the development of MD. The exact pathologic findings characteristic of MD remains unclear, however. Many of the temporal bone specimens were obtained years after patients were diagnosed with MD and those specimens were involved with moderate postmortem changes. For these reasons, further collection of temporal bone specimens with fewer postmortem changes, obtained within a shorter premortem time period between occurrence of the disease and the time of the patients' death, and from patients with a well-characterized clinical history of MD, is imperative. Contemporary temporal bone studies now include in situ hybridization histochemistry or polymerase chain reaction (PCR) analysis for protein, enzymes, or viral antigens that can be directed at specimens from patients with MD [54,55]. It is hoped that in the near future such advanced research studies with human temporal bone histology sections will support and enhance the significant contribution of temporal bone histopathology to clinical otology.