CT and MRI features of cavernous haemangioma of internal auditory canal

A left internal auditory canal (IAC) cavernous haemangioma is reported in a 45-year-old Saudi male. The lesion was associated with rapidly deteriorating hearing loss and facial nerve dysfunction. CT showed a calcified enhanced IAC lesion while T1 weighted MRI showed an isointense contrast enhancing lesion bulging into the porus acousticus. The imaging features of the three usual IAC lesions--meningioma, acoustic neuroma and cavernous haemangioma--were compared. Calcification/ossification appear more commonly in cavernous haemangioma than in the other two lesions while facial nerve dysfunction is a clinical hallmark of IAC cavernous haemangioma.     

Hemangioma of the temporal bone in a patient presumed to have Ménière's syndrome

This case report describes a patient with a facial nerve hemangioma of 8 years' duration that initially caused most of the symptoms of Ménière's syndrome: fullness, sensorineural hearing loss, dizziness, tinnitus, and disruption of balance. The hearing loss was in the high-frequency range (> or = 3,000 Hz); typically, the initial hearing loss in Ménière's syndrome is in the low-frequency range. Mild facial nerve weakness and punctate keratitis due to corneal exposure appeared 8 years later. Contrast-enhanced magnetic resonance imaging and high-resolution computed tomography depicted the lesion and made preoperative diagnosis possible. With meticulous surgical removal of the tumor, which was intertwined with the facial nerve, facial nerve function was preserved.     

A case of reversible deafness in cystic arachnoiditis (author's transl)

A patient studied preoperatively by a neuro-otological test battery showed signs of an extensive cerebellopontine angle tumour. During the operation dense fibrotic tissue was found extending from the choroid plexus to the right acoustic nerve, which was freed and thus decompressed. Postoperatively, low frequency hearing improved markedly in the right ear. In contrast to the well-known documented cases of successful decompression of the optic nerve it has not been possible up to now to achieve a successful outcome in similar procedures on the acoustic nerve. In the described case the fibrotic lesion had obviously just caused reversible damage to the myelin sheaths of the eighth nerve, which can be interpreted as "neurapraxia" (Seddon, 1943). Further investigations in regard to the systematic elucidation of possibly reversible damage to the acoustic nerve are currently being performed at the IInd ENT department of Vienna University.     

Rare differential diagnosis in "vertigo" symptoms

The diagnosis of vestibulocochlear nerve and statoacoustic organ lesions is based on the symptoms vertigo, hearing loss and tinnitus. The most common diseases are vestibular neuronitis, Ménière's disease, benign positional vertigo and sudden hearing loss. 6 patients are presented, complaining of at least one of the symptoms vertigo, hearing loss or tinnitus. They were suspected of suffering from a peripheral audiovestibular disease when admitted to the clinic, but all of them revealed other pathologies. A careful history and step-wise otoneurologic diagnostics including clinical examination, otoneurologic testing, audiologic tests, electronystagmography, acoustic evoked potentials and imaging techniques finally resulted in the correct diagnosis.     

Prognostic factors for hearing preservation following observation-only versus stereotactic irradiation (STI) in patients with acoustic neuroma

Prognostic factors for hearing preservation following observation-only versus STI were compared in patients with acoustic neuroma. There were 48 patients with acoustic neuroma treated by fractionated STI. Between 1991 and 1997, patients were given 36 Gy in 20 fractions over 5 weeks (36 Gy/20 Fr/5 wks) to 44 Gy/22 Fr/6 wks followed by a 4 Gy boost. A linear accelerator was used for irradiation. Twenty-three patients with acoustic neuroma who were followed without any treatment (observation-only group) were selected as matched controls. The largest hearing loss was observed at the frequency of 2 kHz in the observation-only group and at 1-2 kHz in the STI group. Hearing loss at 1 kHz was more frequent in the STI group (p < 0.01). There were no significant prognostic factors which predicted hearing preservation in the observation-only group. Stereotactic irradiation has been suggested to damage to cochlear nerve function in patients whose cochlear nerve had been impaired already. Tumor control rate of STI appeared to be as good as single fraction radiosurgery rates in the literature and better than in the observation-only group. Hearing preservation rate in the STI group was as good as in the observation-only group and appeared to be better than single fraction radiosurgery. In conclusion, because there were no factors predictive of hearing preservation in the observation-only group, it is difficult to select patients for observation only. Fractionated STI is potentially the treatment of choice, resulting in the same hearing preservation rate as achieved with observation only, although longer follow-up periods are needed.     

MRI findings of VIIth cranial nerve involvement in sarcoidosis

Right facial nerve palsy in a 58-year-old woman was due to sarcoidosis demonstrated by Gd-DTPA enhanced MRI. Abnormal enhancement of the right VIIth cranial nerve in the distal internal acoustic canal was seen on MRI. The enhancing lesion was smaller after 1 month of prednisolone 50 mg day-1. This is the first report on facial nerve involvement in neurosarcoidosis examined by Gd-DTPA enhanced MRI. The use of Gd-DTPA enhanced MRI with thin slicing, e.g. 3 mm slice thickness and 1 mm interslice gap, is effective in detecting small extramedullary lesions.     

Mucin-producing tumor of the pancreas: diagnostic value of diffusion-weighted echo-planar MR imaging

It is generally accepted that hemifacial spasm (HFS) and trigeminal neuralgia are caused by compression of the facial nerve (seventh cranial nerve) or the trigeminal nerve (fifth cranial nerve) at the nerve's root exit (or entry) zone (REZ); thus, neurosurgeons generally perform neurovascular decompression at the REZ. Neurosurgeons tend to ignore vascular compression at distal portions of the seventh cranial nerve, even when found incidentally while performing neurovascular decompression at the REZ of that nerve, because compression of distal portions of the seventh cranial nerve has not been regarded as a cause of HFS. Recently the authors treated seven cases of HFS in which compression of the distal portion of the seventh cranial nerve produced symptoms. The anterior inferior cerebellar artery (AICA) was the offending vessel in five of these cases. Great care must be taken not to stretch the internal auditory arteries during manipulation of the AICA because these small arteries are quite vulnerable to surgical manipulation and the patient may experience hearing loss postoperatively. It must be kept in mind that compression of distal portions of the seventh cranial nerve may be responsible for HFS in cases in which neurovascular compression at the REZ is not confirmed intraoperatively and in cases in which neurovascular decompression at the nerve's REZ does not cure HFS. Surgical procedures for decompression of the distal portion of the seventh cranial nerve as well as decompression at the REZ should be performed when a deep vascular groove is noticed at the distal site of compression of the nerve.     

Spin-glass ordering of Fe-doped La2-xSrxCuO4

A series of 238 consecutive patients with acoustic neuromas, operated on in Paris has been studied to identify unusual presentations and varied symptomatology. The most common history was that of a progressive unilateral hearing loss (in 68.1%), with tinnitus (in 49.1%) or disequilibrium (in 49.1%) or both. Sudden hearing loss (in 14.7%) or fluctuating hearing loss (in 6.3%), and a single or repeated episodes of acute vertigo (in 8.8%) were seen less commonly. Headaches occurred as an associated symptom in 10.5%, tinnitus was the sole symptom in 2.8% and other uncommon symptoms included otalgia, facial nerve palsy, facial or ocular pain, altered sensation in the face or eye, or tingling of the tongue. Some 11.3% of patients presented with normal pure tone auditory thresholds and a 100% speech discrimination score and of these patients acoustic reflex thresholds were normal in 53% and brainstem auditory evoked responses were suggestive of the retro-cochlear abnormality in only 76.2%. Amongst the less common presentations, the initial symptoms mimicked such diagnoses as Meniére's disease, benign positional vertigo, vertebro-basilar migraine, vertebro-basilar insufficiency, Bell's palsy and Trigeminal neuralgia. Overall, 20.6% of patients had unusual initial presenting symptoms, 36.5% of the symptoms were unusual and these were found in isolation in 11.8% of patients. An awareness of the spectrum of more subtle symptoms of acoustic tumours may lead to the correct diagnosis at an earlier stage.     

Analyses of neuro-otological complications after radiosurgery for acoustic neurinomas

PURPOSE: To find out the optimum treatment parameters and the proper indications for treatment of acoustic neurinomas, univariate and multivariate actuarial analyses of neuro-otological complications after stereotactic radiosurgery for acoustic neurinomas were performed. METHODS AND MATERIALS: The subjects were 46 patients with acoustic neurinomas who underwent unilateral radiosurgery between June 1990 and June 1994 and were followed up at the University of Tokyo. Age ranged from 13 to 77 years (median, 54 years). Tumor diameter ranged from 0 to 25 mm (mean, 12 mm) at the cerebellopontine angle and from 2 to 15 mm (mean, 8.3 mm) in the internal auditory meatus. Maximum tumor doses ranged from 20 to 40 Gy (mean, 31.4 Gy), and peripheral doses from 12 to 25 Gy (mean, 16.8 Gy). One to eight isocenters were used (mean, 3.2). Median follow-up was 39 months. Eight events concerning neuro-otological complications were chosen, and the potential risk factors for them were analyzed by the actuarial analyses (univariate and multivariate). The events examined include hearing loss, vestibular function loss, facial palsy, and trigeminal nerve dysfunction. In order to point out potential risk factors for neuro-otological complications, univariate analyses were performed using both the Wilcoxon test and the log rank test, and multivariate analyses were performed with the Cox proportional hazards model. Variables nominated as potential risk factors were 1) demographic variables such as patient age and sex, 2) tumor dimensions, 3) treatment variables such as tumor doses and number of isocenters, and 4) pretreatment hearing levels. A variable with significant p-values (p < 0.05) in two or more of the three actuarial analyses (two univariate and one multivariate) was considered a possible risk factor. RESULTS: The possible variables that increase the risk for each event analyzed were: neurofibromatosis type II (NF2) and the number of isocenters for total hearing loss; experience of prior operation, the tumor diameter in the internal auditory meatus, and NF2 for hearing threshold elevation; peripheral tumor dose for vestibular function loss; patient age or midporus transverse tumor diameter (the two variables were correlated), and the number of isocenters for facial palsy; and the number of isocenters for trigeminal neuropathy. CONCLUSION: NF2 and the tumor diameter were the common risk factors for hearing loss in previous studies and ours. For the 5th/7th nerve dysfunction, the tumor diameter was the common risk factor. The risk of using more isocenters remains controversial. The difference in risk factors for hearing impairment and vestibular function loss suggests different mechanisms for the two. Further studies with larger populations and longer follow-up periods are required in order to draw conclusions on the risk factors in radiosurgery.     

Abnormal branching of facial nerve with ossicular anomalies: report of two cases

Two cases with almost identical anomalies of the facial nerve and ossicles were reported. The two girls, ages 9 and 14 years, with unilateral hearing loss underwent exploratory tympanotomy. A huge suprameatal spine and tumor-like swelling of the facial nerve at the tympanic portion as well as its abnormal branching at the pyramidal bend were noted; one of the branches of the facial nerve appeared on the surface of the temporal bone running through the tympanomastoid suture. The distal parts of the long process and lenticular process of incus were missing as if they were eroded by the swollen facial nerve, and the superstructure of the stapes also was absent. No anomaly was seen in any other part of their ears or bodies. This specific type of anomaly is considered rare and important in that surgeons may misdiagnose the swollen facial nerve as a tumor, resulting in facial nerve paralysis due to injury or unnecessary biopsy.     

An evaluation of predicting hearing loss from the acoustic reflex

Three different formulas used in predicting hearing level from acoustic reflex data have been suggested. Acoustic reflex information is also used in predicting slope of hearing loss. Seventy-four normal and hearing-impaired persons were tested, and predictions of level and slope of hearing were compared with pure tone hearing thresholds. The results indicate that the Niemeyer-Sesterhenn and Jerger unweighted formulas yield comparable results and are preferable to the Jerger weighted formula. Predictions of slope of hearing loss are equivocal.     

Active electronic cochlear implants for middle and inner ear hearing loss--a new era in ear surgery. I: Basic principles and recommendations on nomenclature

Hearing aids have fundamental disadvantages: (1) stigmatization of the patient; (2) the sound is often found to be unsatisfactory due to the limited frequency range and undesired distortion; (3) in many patients, the ear canal fitting device generally necessary leads to an occlusion effect; (4) acoustic feedback when amplification is high. Conventional hearing aids transmit sound into the ear canal via a small microphone. Sound has the disadvantage of requiring high output sound pressure levels for its transmission. This along with the necessary miniaturization of the loudspeaker as well as the resonances and reflections in the closed ear canal contribute to the disadvantages mentioned. In contrast, implantable hearing aids do not make sound signals but micromechanical vibrations. An implantable hearing aid has an electromechanical transducer instead of the loudspeaker of a conventional hearing aid. The hearing signal does not leave the transducer as sound but as a mechanical vibration which is directly coupled to the auditory system bypassing the air. This implantable hearing aid is either coupled to the tympanic membrane, the ossicular chain, the perilymph of the inner ear, or the skull. An implantable hearing aid is expected to have: 1 Better sound fidelity than a hearing aid 2 No ear canal fitting device, free ear canal 3 No feedback 4 Invisibility Requirements on electronic hearing implants designed for patients with conductive hearing loss differ from those on implants for sensorineural hearing loss. Conductive hearing loss requires the implant to replace the impedance transformation, thus being an impedance transformation implant (ITI). In various respects, the demands on an ITI are lower than the demands on an electronic hearing aid for patients with sensorineural hearing loss. The latter are mostly patients with a failure of the cochlea amplifier (CA). A damage to the CA is clinically discernible by a positive recruitment and loss of otoacoustic emissions (OAE). Since these patients form the majority of cases with sensorineural hearing loss, an active hearing implant for such patients should partially replace the function of the CA. Therefore, the suggestion is to refer to a CAI (cochlea amplifier implant). The implant expressions ITI (for patients with conductive hearing loss) and CAI (for patients with sensorineural hearing loss) used in this context allow nomenclatural association with the CI (cochlear implant) for complete inner ear failure as well as with the BSI (brainstem implant) in the case of hearing nerve failure.     

Surgery of acoustic neuromas. Preliminary experience with a translabyrinthine approach

Inspired by the works of William House, the authors formed an otoneurosurgical team in order to improve the results after surgery for acoustic neuromas. This paper deals with the preliminary results obtained with the translabyrinthine approach in 13 patients with acoustic neuromas. In 9 patients it was possible to remove the tumor totally with this approach, in 4 patients a second suboccipital operation was necessary to secure total removal. One small, 7 medium and 5 large tumors were encountered. The facial nerve was preserved in 83 per cent of the patients. One patient with a large tumor died after the second suboccipital operation. The relation between size of the tumor and the outcome of the operation is stressed, and in order to reduce the number of large tumors it is suggested that all patients with unilateral hearing loss should be suspected of having a neuroma, until the diagnosis has been disproved. It is concluded that the surgery for acoustic neuromas is otologic-neurosurgical teamwork, and that the treatment should be centralized.     

Fear of childbirth during pregnancy may increase the risk of emergency cesarean section

The clinical features of progression sensorineural hearing loss and vertigo in combination with the radiologic finding of a contrast-enhancing mass within the inner auditory canal are suggestive of an acoustic neuroma. We report our findings in a 57-year-old woman with known mixed connective tissue disease who was presumed to have a neuroma. A large malignant lymphoma of the cerebellopontine angle presented clinically with a primary acoustic none palsy and no other central neurological deficits. Both the primary radiological examinations and the exclusively peripheral nerve palsy failed to indicate manifestations of a lymphoma. The development of a progressive facial palsy within 8 weeks of presentation and an atypical occipital headache were uncommon findings for an acoustic neuroma. Such changes in symptoms despite the occurrence of cardinal symptoms require further diagnostic measures. Manifestations of a malignant lymphoma in the cerebellopontine angle are extremely rare. To our knowledge a case of an intracerebral lymphoma in a patient with Sj?gren's syndrome has never been reported before.     

Accuracy of seven different tests for the diagnosis of Helicobacter pylori infection and the impact of H2-receptor antagonists on test results

The financial burden for the evaluation of patients for acoustic neuroma in an otolaryngology practice is substantial. Patients with sudden sensorineural hearing loss represent a portion of that population seen with unilateral, asymmetric auditory symptoms who require investigation for acoustic neuroma. For these patients, gadolinium-enhanced magnetic resonance imaging is the diagnostic gold standard. Auditory brain stem response testing has been used in the past as a screening test for acoustic neuroma, but its apparent sensitivity has fallen as the ability to image smaller acoustic neuromas has improved. Fast spin echo magnetic resonance imaging techniques without gadolinium have been shown to be as effective in the detection of acoustic neuroma as contrast-enhanced magnetic resonance imaging. Limited nonenhanced fast spin echo magnetic resonance imaging now provides an inexpensive alternative for high-resolution imaging of the internal auditory canal and cerebellopontine angle. Fast spin echo magnetic resonance imaging can now be done at a cost approximating auditory brain stem response testing while providing the anatomic information of contrast-enhanced magnetic resonance imaging. Cost analysis was done in the cases of 58 patients with sudden sensorineural hearing loss by comparing the costs for routine workup and screening of acoustic neuroma with the cost of fast spin echo magnetic resonance imaging with the use of screening protocols based on literature review. The potential cost savings of evaluating patients with sudden sensorineural hearing loss with fast spin echo magnetic resonance imaging for acoustic neuroma was substantial, with a 54% reduction in screening costs. In an era of medical economic scrutiny, fast spin echo magnetic resonance imaging has become the most cost-effective method to screen suspected cases of acoustic tumors at our institution by improving existing technology while reducing the cost of providing that technology and eliminating charges for impedance audiometry, auditory brain stem response testing, and contrast-enhanced magnetic resonance imaging.     

Establishing a link between cultural evolution and sexually transmitted diseases

Measurement results of click evoked otoacoustic emissions (EOAE) and distortion products otoacoustic emissions (DPOAE) in a case of sensorineural hearing loss in a case of sensorineural hearing loss in a patient with a history of oticus zoster with nerve VII palsy are presented. Feasibility of using otoacoustic emissions measurements for hearing loss type identification is discussed.     

Detection of restricted junctional diversity of peripheral T cells in SLE patients by spectratyping

Three patients presented with unilateral sensori-neural hearing disturbance as the initial symptom of cerebellar tumors: a 19-year-old female with a medulloblastoma (Case 1), a 45-year-old male with a cerebellar low-grade glioma (Case 2), and a 49-year-old female with a cerebellaer hemangioblastoma (Case 3). In Cases 1 and 2, the whole length of the eight cranial nerve was intact according to magnetic resonance imaging and intraoperative findings. In Case 3, the intracerebellar tumor had bulged into the cerebellopontine cistern, compressing the eighth cranial nerve near the brainstem. Auditory evoked brainstem responses showed only the first wave in all three patients, and the following waves could not be discriminated. Unilateral sensori-neural hearing disturbance occurs very rarely in patients with intramedullary cerebellar lesions because the auditory neural pathway is bilaterally innervated. Intramedullary tumors may cause unilateral sensori-neural hearing disturbance by infiltrating or causing edematous changes of the eighth cranial nerve or the cochlear nucleus in the brainstem, or by compressing the nerve in the cistern. The symptoms are the same as those of acoustic neurinoma, so intramedullary cerebellar tumors should be considered in the differential diagnosis of unilateral sensorineural hearing disturbance.     

Cholesteatoma of the cerebellopontine angle

Congenital cholesteatoma is the third most common tumor found in the cerebellopontine angle. It must be differentiated from acoustic neuromas, meningiomas, metastatic tumors, arachnoid cysts and lipomas. Symptoms include hemifacial spasm, progressive facial paralysis, hearing loss, tinnitus, vertigo, pain and otorrhea. Radiologic and magnetic resonance imaging frequently can be useful to establish a preoperative diagnosis. The treatment of choice is total removal of the lesion. Complete removal with preservation of normal structures is the most difficult and technically exacting procedure performed by the neurotologic surgeon. The clinical features and results from a series of 19 cases, nine of which extended into the cerebellopontine angle, are discussed.     

Otoacoustic emissions in full-term newborns at risk for hearing loss

Distortion product otoacoustic emissions (DPOEs) and click-evoked otoacoustic emissions (CEOEs) characteristics of the normal newborn population have been previously reported in the literature. There is little information about DPOE evaluations in the newborn population at risk for hearing loss. The authors now report the DPOE and/or CEOE data from six full-term subjects at risk for hearing loss or with highly suspected hearing loss. These subjects were less than 1 year of age and at risk for hearing loss secondary to a history of hereditary hearing loss, meningitis, hyperbilirubinemia, and ototoxic drug exposure. Audiometric evaluation included auditory brainstem responses (ABR), behavioral observation audiometry, and tympanometry. The CEOEs and DPOEs were found to be decreased or absent in the subjects with suspected hearing loss secondary to cochlear pathology; they were found to be normal in a subject with a suspected central hearing loss. This study's data suggest that otoacoustic emissions when combined with ABR can provide a frequency-specific evaluation of cochlear function and help determine the anatomic site of a pathologic lesion.     

Effect of restricted cortical lesions on absolute thresholds and aphasia-like deficits in Japanese macaques.

The effect of small bilateral cortical lesions on pure-tone audiograms and on the ability to discriminate between two types of Japanese macaque coo vocalizations was determined in 4 Japanese macaques. A lesion that included the middle portion of the superior temporal gyrus of both hemispheres, that is, the primary and secondary auditory areas, resulted in a partial hearing loss as well as an inability to discriminate the vocalizations. Lesions that included the ventral portions of the superior temporal gyrus of both hemispheres but spared auditory cortex on one side also resulted in a partial hearing loss but had either a small effect or no effect on the ability to discriminate the vocalizations. Bilateral ablation of the dorsal superior temporal gyrus and adjacent parietal and occipital areas did not result in a hearing loss and had no effect on the ability to discriminate the vocalizations. Results suggest that a hearing loss may be produced by lesions that involve small portions of the ventral two-thirds of the superior temporal gyrus bilaterally although the resulting loss is not as great as that observed with larger lesions. However, the aphasia-like deficit appears to result from a lesion of primary and/or secondary auditory cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)