1/10. Isolated metastases of adenocarcinoma in the bilateral internal auditory meatuses mimicking neurofibromatosis type 2--case report.A 56-year-old male with a history of lung cancer presented with isolated metastases of adenocarcinoma in the bilateral internal auditory meatuses (IAMs), mimicking the bilateral acoustic schwannomas of neurofibromatosis type 2, and manifesting as rapidly worsening tinnitus and bilateral hearing loss. magnetic resonance imaging showed small tumors in both IAMs with no sign of leptomeningeal metastasis. The preoperative diagnosis was neurofibromatosis type 2. Both tumors were removed and the histological diagnoses were adenocarcinoma. neuroimaging differentiation of a solitary metastatic IAM tumor from a benign tumor is difficult, although rapidly progressive eighth cranial nerve dysfunction suggests a malignant process. Metastases should be considered as a rare diagnostic possibility in a patient with small tumors in both IAMs.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/10. Intraosseous dural arteriovenous fistula of the skull base associated with hearing loss. Case report.The most common clinical presentations of dural arteriovenous fistulas (DAVFs) are bruit, headache, increased intracranial pressure, and intracranial hemorrhage. In particular locations, such as the cavernous sinus or middle cranial fossa, cranial nerve involvement due to dural arterial steal or venous occlusion may develop. A case in which a DAVF is associated with hearing loss, however, has not previously been reported. The authors report a case in which an intraosseous DAVF and associated hearing loss probably resulted from cochlear nerve or vascular compression caused by the draining vein or nidus of the DAVF.- - - - - - - - - - ranking = 2keywords = nerve (Clic here for more details about this article) |
3/10. Postoperative hearing recovery in a case of delayed hearing loss after acoustic neurinoma removal.Delayed postoperative hearing loss after acoustic neurinoma removal is seldom observed. The presented case illustrates the phenomenon of delayed postoperative hearing loss which was observed 4 days after removal of a large acoustic neurinoma. Intraoperative brainstem auditory evoked potentials (BAEP) revealed a gradual loss of wave V with preservation of wave I. In animal experiments a dissociated loss of BAEP has been associated with impairment of microcirculation due to secondary edema. Vasoactive treatment was initiated and after 11 days a partial hearing recovery could be documented. Transient disturbance in microcirculation of vasa nervorum of the cochlear nerve is assumed to be responsible for postoperative hearing fluctuation.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
4/10. Is preservation of hearing in acoustic neuroma worthwhile?In a series of 300 translabyrinthine removals of acoustic neuromas, comprising almost all tumours operated on in denmark during a period of 10 years, the preoperative hearing in the tumour ear and in the contralateral ear was analysed in 72 patients with tumours smaller than 2 cm in extrameatal diameter. These patients constitute likely candidates for a hearing preserving operation via the suboccipital approach. In the tumour ear in 4 patients there was a pure-tone average (PTA) of 0-20 dB and a discrimination score (DS) of 81-100%. Applying this criterion to the whole series, 1% of the patients would be candidates for a hearing preserving procedure. Changing the criterion to a PTA of 0-40 dB and a DS of 61-100%, the number of candidates would increase to 8 patients (3%), and with a PTA of 0-50 dB and a DS of 51-100% 14 candidates (5%) would have been found. In all of these patients, contralateral hearing was normal (SRT 0-20 dB, DS 95-100%). Since preservation of hearing would be achieved in only half of those subjected to suboccipital removal and since the hearing retained in patients with successful operations is generally poorer than the preoperative level, the number of patients obtaining serviceable hearing is so modest that preservation of hearing cannot be considered an argument in favour of suboccipital tumour removal. It should be borne in mind that contralateral hearing is normal in these patients and that, according to most reports, the mortality rate is higher and paralysis of the facial nerve more frequent with the suboccipital approach than with the translabyrinthine procedure.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
5/10. Auditory Brainstem Response audiometry. Applications in central disorders.ABR is the most sensitive and specific test in the audiology battery for detecting disorders that affect the brainstem. When combined with central speech audiometry, ABR can detect most intra- and extra-axial tumors, demyelinating lesions, and polyneuropathies that affect brainstem auditory structures. Alone, it is a promising tool for monitoring neural maturation, tumor growth, coma, and neurologic or vascular therapies. The test can be severely compromised by peripheral hearing loss and knowledge of the audiogram is a prerequisite for any central testing application of ABR. Six cases of intra- or extra-axial brainstem pathology are described here. ABR results were abnormal in all but one case, based on response latency measurements. In two cases, ABR was the only audiologic test that detected the abnormality. In general, ABR was sensitive to and conventional tests were insensitive to central lesions involving the eighth nerve. ABR abnormalities were not in themselves sufficient to define the precise site of the lesion, nor could they determine the kind of lesion present. However, they were indicative of the level and extent of direct involvement by the disease process or of the pressure and distortion effects of the lesion on the brainstem. In one case where ABR failed to detect the lesion, central speech testing was abnormal. The potential usefulness of ABR to monitor brainstem status is emphasized. A case is described where ABR provided valuable information on the effects of an experimental embolic therapy for AVM. Special precautions are described for monitoring ABR in neonates. ABR is an important screening test for the detection of brainstem disorders, especially those that cannot be detected radiographically. Its greatest use, however, may prove to be as inexpensive and noninvasive monitor of brainstem status in patients with confirmed or suspected brainstem disorders.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
6/10. The effect of degree of hearing loss on diagnostic test strategy: report of a case.We discuss test results in a single case of eighth nerve disorder. The patient was evaluated twice, once when sensitivity loss was only mild and once when sensitivity loss was severe. Diagnostic contribution of individual test measures depended on degree of sensitivity loss. When the loss was only mild, the acoustic reflex test and auditory brain-stem response (ABR) audiometry were most sensitive to eighth nerve disorder. When sensitivity loss was severe, results of the acoustic reflex test and ABR audiometry became ambiguous. At that time, the more "traditional" audiometric test battery of Bekesy audiometry, suprathreshold adaptation test (STAT), and speech audiometry provided the most useful diagnostic information. Since degree of sensitivity loss at the time of initial evaluation is an uncontrollable variable, diagnostic strategy must include tests appropriate to a wide range of hearing loss.- - - - - - - - - - ranking = 2keywords = nerve (Clic here for more details about this article) |
7/10. Auditory brainstem responses in leptomeningeal metastatic spread. Presentation of 2 cases.Auditory brainstem responses (ABRs) were recorded in 2 patients with hearing loss caused by leptomeningeal metastatic spread. These recordings showed similar characteristic findings. The absolute latencies of wave V and interwave latencies I-V were exceedingly increased. Definite effects on the wave morphology and latency of wave V were observed with the use of high repetition rates. It is surmised that the hearing loss caused by leptomeningeal metastatic spread is mainly an effect on the auditory nerve and/or the cochlear nucleus. ABR examination is of clinical value in detecting functional abnormalities resulting from leptomeningeal metastatic spread.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
8/10. A case of cerebellar infarction occurred with the 8th cranial nerve symptoms.A rare case, 32-year-old man, of cerebellar infarction with the occurrence of the 8th cranial nerve symptoms was reported. On the neuro-otological examination, hearing test and caloric test showed a severe hearing loss and no response on the right side, respectively, and the spontaneous horizontal nystagmus fixed to the left direction was observed. Magnetic resonance (MR) imaging showed the infarctions in the areas of anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (pica) on the right side. On the 14th illness day, the 8th cranial nerve symptoms disappeared, and on the 12th illness day, right hearing level and caloric response were significantly improved. We suggested that such an early recovery of the subjective symptoms and neuro-otological findings may be attributable to the recanalized circulation disturbance or the development of collateral circulation.- - - - - - - - - - ranking = 6keywords = nerve (Clic here for more details about this article) |
9/10. role of acute cochlear neuritis in sudden hearing loss in multiple sclerosis.We report a patient with definite multiple sclerosis (MS) who developed unilateral sudden hearing loss coincident with exacerbation of central nervous system symptoms. Involvement of the peripheral cochlear nerve, suggested by auditory findings including auditory brainstem response, was confirmed by magnetic resonance imaging. The clinical, electrophysiological and neuroradiological abnormalities disappeared in response to steroid pulse therapy. These findings suggest that acute inflammatory demyelinative lesion of the peripheral cochlear nerve can occur in MS, manifesting sudden hearing loss.- - - - - - - - - - ranking = 2keywords = nerve (Clic here for more details about this article) |
10/10. Unilateral sensori-neural hearing disturbance caused by intramedullary cerebellar tumors--three case reports.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.- - - - - - - - - - ranking = 4keywords = nerve (Clic here for more details about this article) |
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