The influence of race on the position of the jugular bulb

Influence of pneumatization on morphology of temporal bone-related vasculatures and their morphometric relationship with ear regions: a computed tomography study

Anatomical variations in the location and position of temporal bone-related vasculature are routinely encountered in clinical practice, contributing to clinical syndromes and complexities in ear-related and neurological surgeries. Pneumatization of the temporal bone (TB) is one of several factors that have been hypothesized to influence the variabilities and variations of these vessels. This study aimed to investigate the association between the degree of pneumatization and the morphologies of some TB-related vessels, as well as their morphometrical relationship with ear regions. Observational retrospective chart review of 496 TBs computed tomographic scans were examined. Different degrees of pneumatization were observed, with hyper-pneumatization being the most common and hypo-pneumatization being the least. Various anatomical variants of the sigmoid sinus (SS), jugular bulb (JB), and internal carotid artery (ICA) were observed. Distances of SS and JB to ear regions were observed to have significant differences (p < 0.05) in laterality. These distances increased relative to increased air cells, showing a significant association (p < 0.05). A significant association (p < 0.001) was also observed between the degree of pneumatization and variants of JB and ICA. High JB, JB dehiscence, and ICA dehiscence were significantly associated with increased pneumatization, while flat JB was significantly associated with decreasing pneumatization. However, no significant association (p = 0.070, p = 0.645) was observed between the degree of pneumatization and morphologies of SS. This study concludes that the degree of pneumatization influences only the jugular bulb variants and ICA dehiscence, as well as the distances of SS and JB to ear regions.

High jugular bulb in a cohort of patients with definite Ménière's disease

OBJECTIVE

To determine the incidence of high jugular bulb in a group of patients with definite Ménière's disease, and to investigate whether the position or size of the jugular bulb is significantly different in the affected ear than in the unaffected ear.

METHODS

Retrospective review of patient charts, audiograms, and computed tomography scans to determine the position and size of the jugular bulb in the affected and contralateral ears, as well as other abnormalities.

RESULTS

High jugular bulb was found in 57.1 per cent of affected ears. Encroachment of the cochlear and vestibular aqueducts was apparent in 39.3 per cent and 35.7 per cent, respectively, of affected ears. Diverticulum and dehiscence were observed in 28.6 per cent of affected ears. High jugular bulb was significantly associated with encroachment of the cochlear aqueduct (p = 0.003).

CONCLUSION

The mediolateral and anteroposterior position of the jugular bulb determines encroachment of the surrounding structures. An abnormal position is postulated to contribute to the development of Ménière's disease.

An anatomical and radiological study of the high jugular bulb on high-resolution CT scans and alcohol-fixed skulls of adults

Although many reports mention a "high jugular bulb" (HJB), it is often not clearly defined. We examined the relationship between the jugular bulb (JB) and the internal auditory canal (IAC) in 200 temporal bones on high resolution CT scans and alcohol-fixed skull bases of adults. The average distance (+/-standard deviation) between the IAC and the JB was 7.5+/-2.3mm (range, 1-16 mm). The JB was higher on the right side than its companion in 53.3% of patients (left side only in 22%; no side dominance in 23.7% of bases). When the JB reached or exceeded the floor of the IAC (16.5%), it was defined as a HJB; 61% of HJB were found in females. Bilateral HJB was found in 0.5% of patients. The HJB was not associated with a contralateral flat JB. Preoperative multiplanar high resolution CT reconstructions make the most detailed assessment of structural topography.

Uncommon otological manifestations of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is significant for the otologist although the nasopharynx is located outside the anatomical confines of the ear. Middle-ear effusion resulting from NPC is well-known. There are however, other less common ear symptoms of NPC that many physicians are not sufficiently aware of. A personal series of patients with NPC presenting with uncommon symptoms relating to the ear is presented. These include NPC presenting as a) haemotympanum b) a peri-auricular mass c) referred sensation to the ear d) blocked ear e) barotrauma f) an ear polyp g) sudden sensorineural hearing loss. These symptoms may pose diagnostic difficulties, resulting in the diagnosis of NPC being delayed. It was concluded that a high index of suspicion for NPC is warranted in high risk patients presenting with unexplained otological symptoms.

Influence of phylogeny on jugular fossa shape and otological disorders

We examined the shape of the jugular fossa and its protrusion into the tympanic cavity in 51 human skulls and in 355 various monkey skulls. All human specimens had a done-shaped fossa, and the right fossa was larger than the left in 60 per cent of the specimens. Fossae protruded into the tympanic cavity in 20 per cent of these specimens. In contrast, none of the monkey specimens had a dome-shaped fossa. Some monkeys had saucer-shaped jugular fossa; the frequency of such fossa became higher as phylogeny progressed. Furthermore, the jugular fossae in monkeys did not protrude into the tympanic cavity. The shapes of both the jugular fossa and sulcus of the transverse sinus were generally symmetrical. The shape of the jugular fossa and its positional relationship to the tympanic cavity were considered from the viewpoint of the influence of phylogeny and the possible relationship to various otological problems.