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.

The circulatory influence on development of age-related macular degeneration and hearing and equilibrium impairments.

This study attempts to answer the question if any level of head and neck circulation takes a part in development of Age-Related Macular Degeneration (ARMD) and hearing and equilibrium impairments. Condition of large blood vessels was examined by Color-Doppler ultrasound, and carotid and ophthalmic arteries were included. The microcirculatory changes were examined directly by fundus photography and fluorescein angiography and indirectly testing hearing and equilibrium. The study group included 40 patients (21 females, 19 males) aging from 53 to 84 years with different stages of ARMD. The control group included 40 patients (18 females, 22 males) aging from 51 to 82 years without ARMD. Patients were inhabitants of Primorsko-Goranska County. There was no relationship between ARMD and condition of large blood vessels because significant stenosis of carotid arteries was found in 2 patients (5%) in study group and 3 patients (7.5%) in the control group (p > 0.05). On the contrary, we found correlation between ARMD and hearing (p = 0.0127) and equilibrium impairments (p = 0.0242). Fluorescein angiograms shows raised number of ischemic retinal capillaries in patients with ARMD (p = 0.0053). Results lead to conclusion that circulatory disorders on microcirculatory level take a great part in development of ARMD and hearing and equilibrium impairments in the elderly. The key is damage of sensory cells of the retina and inner ear caused by microcirculatory disorders. Interesting data was noticed that 9 patients with more serious ARMD on one side of head had greater hearing loss on the same side. If we find a new treatment for microcirculatory disorders, maybe we can treat both sensory impairments in earlier stage.

Three-dimensional computed tomography imaging of the eustachian tube lumen in patients with patulous eustachian tube.

BACKGROUND: The eustachian tube (ET) has a complicated anatomy, which is related to middle ear pathology. The anatomy of the ET has been well investigated in cadavers, but may not accurately reflect that in living subjects. Three-dimensional (3D) computed tomography (CT) was used to examine the ET in patients with patulous ET. METHOD: The subjects were 35 patients (17 males, aged 59 +/- 16 years, and 18 females, aged 44 +/- 15 years) with patulous ET which could be continuously traced from the pharyngeal orifice to the tympanic orifice (53 ears). CT was performed in the sitting position at rest, followed by 3D reconstruction. The course of the ET from the middle ear to the pharynx was visualized in 3D surface images. Morphological measurements of the curvature angle (angle C) and the inclination angle (angle I) were determined from 3D coordinates on the CT images. RESULTS: The full length of the ET could be visualized in most patients suffering from patulous ET in the sitting position. Angle C was 21.7 +/- 5.8 degrees in the patients aged <40 years (n = 20), which is significantly larger than 16.7 +/- 6.8 degrees in the patients aged >59 years (n = 18; Student's t test, p < 0.05). Angle I was 26.5 +/- 4.2 degrees in the patients aged <40 years (n = 20), also significantly larger than 21.6 +/- 5.8 degrees in the patients aged >59 years (n = 18; Student's t test, p < 0.05). CONCLUSION: CT in the sitting position is a potential diagnostic tool of the ET and middle ear pathology.

Relationship between auditory pathway fractional anisotropy and audibility in patients with cerebellopontine angle tumors on diffusion tensor imaging.

OBJECTIVE: Recent reports demonstrated that acoustic nerve disorders affect the auditory pathway on diffusion tensor imaging (DTI). The aim was to investigate whether auditory pathway fractional anisotropy (FA) values are associated with audibility in patients with cerebellopontine angle tumors. PATIENTS AND METHODS: Patients with cerebellopontine angle tumors were included in this retrospective study. Preoperatively, all patients underwent magnetic resonance imaging (MRI) including DTI. Two regions of interest on the lateral lemniscus (LL) and inferior colliculus (IC) were set bilaterally on DTI. FA values were calculated using software. Correlations between FA values and audibility were evaluated using Spearman's rank correlation coefficient. Statistical significance was defined as p < 0.05. RESULTS: Seventeen patients with cerebellopontine angle tumors were included in this study. FA values in the bilateral LL showed a significant negative correlation with hearing impairment severity (r = -0.758, -0.600, p < 0.05). FA values on the ipsilateral side of the IC showed a significant negative correlation with hearing impairment severity (r = -0.477, p < 0.05). FA values on the contralateral side of the IC did not correlate with hearing impairment severity (r = -0.201, p > 0.05). One patient with a low FA value on the contralateral side of the IC had postoperative hearing impairment despite good preoperative hearing ability. CONCLUSIONS: FA values in the bilateral LL and on the ipsilateral side of the IC reflected hearing impairment severity. Decreased FA values on the contralateral side of the IC might predict hearing impairment postoperatively.

Diagnostic evaluation of neck torsion test in objective examination in patients with vertigo and/or hearing-impairment.

INTRODUCTION: The aim of the study was to evaluate the neck torsion test in objective examinations of patients with vertigo and/or hearing loss. MATERIAL AND METHODS: The study was conducted in 100 patients, including 54 women and 46 men aged 17-79 years, who were divided into two groups: I - 50 patients, including 30 women and 20 men aged 17-79 years (mean age 49.92 years) with dizziness and/or hearing impairments, and confirmed asymmetry of intracranial vessels, II - 50 patients - control group, including 24 women and 26 men aged 20-71 years without dizziness and/or hearing disorders and without disturbance in the construction of intracranial vessels. For each patient, the following tests were carried out: subjective, objective otorhinolaryngological, Doppler ultrasound specifying diameter of vertebral and carotid arteries and the velocity of blood flow in these vessels, audiological diagnostics, including the examination of latency of waves I, III, V of the auditory evoked potentials of the brain stem, otoneurological diagnostics with used the neck torsion test. RESULTS: It appears from the analysis of the material presented that the application of the neck torsion test in the Doppler ultrasound results in the fact that the difference in the mean systolic velocity of blood flow in vertebral artery is higher on the side opposite to the turning of the neck, and the increase in the average diastolic blood flow velocity in the vertebral artery on the side of the test being performed and its reduction on the opposite side in the study group, when compared to the control group. The value of the wave I, II, V latency in the ABR test during the neck torsion test is extended more in the study group than in the controls, on the side of the performed test. The performed neck torsion test in the VNG test increases the occurrence of both, square waves and nystagmus (much higher in the study group than in the controls). Conclussion. The application of the neck torsion test in the Doppler ultrasound, ABR and VNG test in patients with vertigo and/or hearing loss means that these tests become functional, thereby increasing their diagnostic value and may be used to monitor the rehabilitation of inner ear disorders.

Diagnostic evaluation of neck torsion test in objective examination in patients with vertigo and/or hearing impairment.

INTRODUCTION: The aim of the study was to evaluate the neck torsion test in objective examinations of patients with vertigo and/or hearing loss. MATERIAL AND METHODS: The study was conducted in 100 patients, including 54 women and 46 men aged 17-79 years, who were divided into two groups: I - 50 patients, including 30 women and 20 men aged 17-79 years (mean age 49.92 years) with dizziness and/or hearing impairments, and confirmed asymmetry of intracranial vessels, II - 50 patients - the control group, including 24 women and 26 men aged 20-71 years without dizziness and/or hearing disorders and without disturbance in the construction of intracranial vessels. For each patient, the following tests were carried out: subjective, objective otorhinolaryngological, Doppler ultrasound specifying the diameter of vertebral and carotid arteries and the velocity of blood flow in these vessels, audiological diagnostics, including the examination of latency of waves I, III, V of the auditory evoked potentials of the brain stem, otoneurological diagnostics with used the neck torsion test. RESULTS: It appears from the analysis of the material presented that the application of the neck torsion test in the Doppler ultrasound results in the fact that the difference in the mean systolic velocity of blood flow in vertebral artery is higher on the side opposite to the turning of the neck, and the increase in the average diastolic blood flow velocity in the vertebral artery on the side of the test being performed and its reduction on the opposite side in the study group, when compared to the control group. The value of the wave I, II, V latency in the ABR test during the neck torsion test is extended more in the study group than in the controls, on the side of the performed test. The performed neck torsion test in the VNG test increases the occurrence of both, square waves and nystagmus (much higher in the study group than in the controls). CONCLUSION: The application of the neck torsion test in the Doppler ultrasound, ABR and VNG test in patients with vertigo and/or hearing loss means that these tests become functional, thereby increasing their diagnostic value and may be used to monitor the rehabilitation of inner ear disorders.

Salicylate-induced frequency-map reorganization in four subfields of the mouse auditory cortex.

Salicylate is the active ingredient in aspirin, and in high-doses it is used as an experimental tool to induce transient hearing loss, tinnitus, and hyperacusis. These salicylate-induced perceptual disturbances are associated with tonotopic-map reorganization and neural activity modulation, and such neural correlates have been examined in the central auditory pathway, including the auditory cortex (AC). Although previous studies have reported that salicylate induces increases in noise-burst-evoked neural responses and reorganization of tonotopic maps in the primary AC, little is known about the effects of salicylate on other frequency-organized AC subfields such as the anterior auditory, secondary auditory, and dorsomedial fields. Therefore, to examine salicylate-induced spatiotemporal effects on AC subfields, we measured sound-evoked neural activity in mice before and after the administration of sodium salicylate (SS, 200 mg/kg), using flavoprotein auto-fluorescence imaging. SS-treatment gradually reduced responses driven by tone-bursts with lower (≤8 kHz) and higher (≥25 kHz) frequencies over 3 h, whereas evoked responses to tone-bursts within middle-range frequencies (e.g., 12 and 16 kHz) were sustained and unchanged in the four subfields. Additionally, in each of the four subfields, SS-treatment induced similar reorganization of tonotopic maps, and the response areas selectively driven by the middle-range frequencies were profoundly expanded. Our results indicate that the SS-induced tonotopic map reorganizations in each of the four AC subfields were similar, and only the extent of the activated areas responsive to tone-bursts with specific frequencies was subfield-dependent. Thus, we expect that examining cortical reorganization induced by SS may open the possibility of new treatments aimed at altering cortical reorganization into the normative functional organization.

The evaluation of the neck torsion test in subjective examinations of patients with vertigo and/or hearing loss.

INTRODUCTION: The aim of this work was to evaluate the diagnostic value of the neck torsion test in VNG, Doppler ultrasonography and brainstem auditory evoked potentials in patients with vertigo and/or hearing loss due to intracranial vascular malformations. MATERIAL AND METHODS: The study covered 47 patients, 30 female and 17 male (mean age, 55.5 years; range, 19-74 years) with vertigo and/or hearing disorders and the asymmetry of vertebral arteries. Each patient underwent a subjective examination, an otolaryngological examination, otoneurological diagnostics, VNG with gaze tracking in the straight ahead position and in the 600 left and right neck torsion, the neck torsion test, audiological diagnostics including I-, III- and V-wave latency of the brainstem evoked potentials in the straight ahead position and the right ear stimulation in the 600 right neck torsion and the left ear stimulation in the neck torsion to the left, Doppler ultrasonography with measuring the diameter of vertebral arteries and the velocity of the blood flow in these vessels with the use of the neck torsion test. RESULTS: In own study, in VNG, the positive neck torsion test was observed in 76.5% of the study patients, while square waves in both directions were found in 46.5% and in one direction in 10.6%. Cervical nystagmus was noticed in 19.1% of these patients. In the auditory evoked potentials test, the differences in I-, III- and V-wave latency time were not statistically significant, either at rest or in the neck torsion. In the Doppler ultrasound examination, the asymmetry of vertebral arteries were present (below 25%) in 7 women (14.9%) and 4 men (8.5%), whereas large asymmetries (above 25%) were observed in 23 women (48.9%) and 13 (27.7%) men (range, 25% - 215%) and was statistically insignificant. The resting blood flow velocity in vertebral arteries of large asymmetries, both in systole and diastole heart phases, was significantly higher in the artery with larger asymmetry. CONCLUSION: The neck torsion test can be diagnostically useful in monitoring the vertebrobasilar system as well as qualify for microsurgical procedures if the vertebrobasilar insufficiency has been diagnosed.

Prevalence and mechanisms of hearing loss in patients with resistance to thyroid hormone.

Hearing impairment was anecdotally reported in resistance to thyroid hormone (RTH), a condition caused by mutations in the beta-thyroid hormone receptor (beta TR) gene. Because of its ontogenic distribution in the cochlea, the beta TR may have a pivotal role in the development of auditory function. To assess the prevalence and mechanisms of hearing impairment in RTH, 82 RTH-positive (RTH+) patients and 55 unaffected relatives (RTH-) underwent systematic audiological examination, including puretone and speech reception thresholds, and tests studying middle ear (tympanometry and acoustic reflexes), cochlear (otoacoustic emissions), and retrocochlear integrity (brain stem auditory evoked potentials). Significant hearing loss was present in 21% of RTH+ patients vs. none in RTH- patients. More RTH+ patients had abnormal tympanometry (34% vs. 12%) and abnormal acoustic reflexes (39% vs. 19%). Isolated conductive deficit was found in 7 of 17 RTH+ patients with hearing loss, isolated sensorineural deficit in 7 cases, and mixed deficit in 3 cases. Cochlear dysfunction was found in 50% of all RTH+ patients, with or without hearing loss. Retrocochlear function was normal. No morphological cochlear abnormalities were detected on computed tomography of the temporal bone. In conclusion, hearing loss is a significant problem in RTH, with an equal frequency of conductive (probably related to the frequent ear infections) and sensorineural deficits. Abnormal otoacoustic emissions suggest that the mutant beta TR has a specific negative impact on cochlear function.

X-linked stapes gusher: CT findings in one patient.

A 31-year-old male patient presented with progressive mixed hearing loss since birth. A stapedectomy was attempted and was unsuccessful because of perilymph gushing. CT of the temporal bones showed bulbous dilatation of the fundi of the internal auditory canals and absence of the bone plates separating them from the base of the cochleas. This unusual abnormality was found after the attempted stapedectomy and explains the clinical findings. The findings in male patients are fairly typical X-linked congenital deafness.

Endolymphatic sac surgery in Mondini's dysplasia: a report of 16 cases.

This paper presents 12 patients (16 ears) with radiographic evidence of Mondini's dysplasia who underwent endolymphatic sac surgery. And additional 4 patients (7 ears) on whom surgery was not performed are included. Class I or II results were obtained in 81% of the ears. Pathophysiology, as it relates to the fluctuant nature of the hearing impairment, is discussed.

Cochlear implants in children.

Cochlear implants allow the rehabilitation of children with severe to profound hearing loss. They are beneficial for not only postlingual children with hearing loss but also for children with congenital or prelingual hearing loss. Issues regarding cochlear implant candidacy and surgery are discussed. The results of cochlear implants in children and the complications related to cochlear implant surgery in children are reviewed.

[High-resolution computed tomography in diseases of the inner ear]. / Hochauflösende Computertomographie bei Erkrankungen des Innenohres.

High-resolution CT of the petrous bone was carried out in 259 patients with clinically diagnosed abnormalities of the inner ear; in some the lesions were bilateral. In 62 patients (approximately 20%), the scans showed findings which related to the signs and symptoms. Patients with hearing loss and vestibular neuronitis showed no abnormalities. Amongst the remaining patients, the most common findings were acoustic neuromas (17 cases), cochlear otospongiosis (14 cases), malformations (13 cases) and tumours or cholesteatomas of the labyrinth (13 cases) as well as single rare isolated lesions.

Three-dimensional x-ray computed tomography of the temporal bone as an aid to surgical planning.

Three-dimensional x-ray computed tomography (3DCT) has been useful in planning surgical procedures involving craniofacial reconstruction, the pelvis, hip, spine, knee and shoulder. The clinical use of 3DCT in temporal bone surgery has not been evaluated. We used 3DCT to assess temporal bone anatomy in 9 patients. These cases evaluated two encephaloceles, two postinflammatory dehiscences, two temporal bone fractures, one glomus jugulare tumor, one acoustic neuroma, and one meningioma. We found 3DCT useful in these temporal bone applications as a supplement to standard two-dimensional CT scanning (2DCT). While 3DCT provided a better preoperative understanding of the underlying anatomy, no treatment was modified solely on the basis of the information derived from the 3-D presentation of data. We conclude that, although 3DCT images have some qualitative advantages over 2DCT techniques, their value in further defining temporal bone morphology must be evaluated against the cost entailed by their use.

Surgery of incidental intracranial aneurysms.

A series of nine patients with an unruptured asymptomatic aneurysm not associated with a ruptured aneurysm is discussed. Three had giant aneurysms. Two patients had bilateral aneurysms of the middle cerebral artery. Five had solitary aneurysms of the middle cerebral artery. One had an aneurysm of the anterior communicating artery. One had an ophthalmic aneurysm. All aneurysms were clipped. Two operations were necessary in the two patients with bilateral aneurysms. There was no mortality and no significant morbidity. Clipping of the aneurysm is recommended for those patients who have no other serious illness that significantly increases the surgical risk. If a combination of pituitary tumor and aneurysm is found, a subfrontal instead of transsphenoidal approach should be considered so as to treat both the tumor and aneurysm at the same operation.

Polytomography and congenital anomalies of the ear.

Conventional radiography and even high resolution computerized axial tomography leave much to be desired in demonstrating the minutiae of the anatomy of the temporal bone. Multidirectional tomography remains the examination of choice radiographically in cases of congenital anomalies of the temporal bone. Details of the inner, middle and even external ear in the presence of atresia are more clearly delineated by this method than any other to data. Such information is of inestimable value to the surgeon in the diagnosis and surgical correction of anomalies of the temporal bone. Important features of the vestibule, semicircular canals, cochlea, facial nerve, internal auditory canal, temporomandibular joint, pneumatization of the temporal bone, tegmen, tympanic cavity, ossicles, oval and round windows, jugular bulb and carotid artery and the external ear canal are discerned most clearly by multidirectional tomography.

Linear accelerator-based radiosurgery for vestibular schwannoma.

Despite major advances in skull base surgery and microsurgical techniques, surgery for vestibular schwannoma (VS) carries a risk of complications. Some are inherent to general anesthesia and surgery of any type and include myocardial infarction, pneumonia, pulmonary embolism, and infection. Some are specific to neurosurgery in this area of the brain, and include hydrocephalus, cerebrospinal fluid leak, facial nerve paralysis, facial numbness, hearing loss, ataxia, dysphagia, and major stroke. Even in the hands of very experienced acoustic surgeons, these risks cannot be eliminated. Radiosurgery provides an outpatient, noninvasive alternative for the treatment of small acoustic schwannomas. Initially radiosurgery was undertaken in "high-risk" patients, including the elderly, those with severe medical comorbidities, and those in whom tumors recurred after surgery. Additionally, a high rate of cranial nerve morbidity was reported. With improvements in dosimetry planning and dose selection, however, authors practicing at radiosurgical centers now report very low complication rates, as well as high tumor control rates. In this report the authors specifically review the results of linear accelerator-based radiosurgery for VS and compare these outcomes with the best surgical alternatives.

Preservation of functional hearing after gamma knife surgery for vestibular schwannoma.

OBJECT: The goal of this retrospective study was to define the rates of preservation of functional hearing and growth control of vestibular schwannomas (VS) treated by gamma knife surgery (GKS) involving a consistent 12-Gy prescription dose. METHODS: One hundred thirty-four patients with unilateral VS underwent GKS between 1994 and 2000. The mean magnetic resonance (MR) imaging follow-up period was 31.7 months (maximum 72 months), and the mean audiometry follow-up interval was 26.3 months (maximum 60 months). The mean marginal dose was 12 +/- 0.6 Gy. The mean maximum dose delivered to the tumor center was 25.4 Gy (range 17.4-34.3 Gy). The tumor control rate, defined as no change or a reduction in size at last follow up, was 96.7%. Of the patients studied, 97.7% remained free from the need to undergo tumor resection. Overall functional hearing preservation was 61.7%; the preservation rate for intracanalicular tumors was 63.6%, for those with an intracranial diameter less than 1.5 cm it was 54.5%, for those between 1.5 and 3 cm it was 68.2%, and for those larger than 3 cm it was 33.3%. Early in the series, three patients (2.2%) developed temporary facial weakness (House-Brackmann Grade II-III) in the posttreatment period, but this resolved within a few weeks. No case of facial weakness occurred after 1996. CONCLUSIONS: The authors demonstrated the efficacy, safety, and in many ways, the advantage of GKS over microsurgery for VS. Patients harboring tumors 3 cm or smaller in intracranial diameter, regardless of their age and medical condition, should be given the option of undergoing GKS as primary treatment.

Radiology of congenital hearing loss.

Thin-section high-resolution computed tomography with "bone algorithm" remains the examination of choice for evaluation of congenital ear malformations. It furnishes the best anatomic detail for planning the surgical approach and avoiding unfortunate intraoperative events secondary to variant courses of vessels and nerves.

Minute findings of inner ear anomalies by three-dimensional CT scanning.

In actual clinical situations, inner ear anomalies must be diagnosed by image diagnosis such as high resolution CT-scanning of the temporal bone before three dimensional (3D) CT-scanning was introduced. In this paper, the usefulness of 3D-CT was investigated in some anomaly cases. It was found that 3D-CT was useful in observing the minute structure of the inner ear in that it could ascertain spatial relationships and minute constrictions and protrusions that could not be detected by 2D analysis. This CT was also capable of assessing the stage of embryological injuries and evaluating anomalies in cochlear turning that are the hidden factors of hearing impairment.