摘要:

We present a new approach to the skull base, medial and superior to the internal auditory canal, for tumors involving the anterior-superior cerebellopontine angle, petrous apex, and clivus. This approach is accomplished through a middle fossa craniotomy and involves removal of the bone anterior and medial to the internal auditory canal and medial to the cochlea and carotid artery. It combines the advantages of complete tumor removal, low mortality rate, and hearing preservation.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The prognostic value of electrocochleography and of the glycerol dehydration test in Meniere's disease is well recognized. Abnormal electrocochleographic waveforms carry a poorer prognosis. After adequate dehydration, significant threshold changes for better or worse predict the likely course of events following endolymphatic sac surgery.Meniere's disease frequently becomes bilateral. Vestibular aqueduct tomography in patients with Meniere's disease gives very different results, in both ears, compared with those in control patients. The acetazolamide cochlear hydration test can help detect latent hydrops. Plasma osmolality studies are an essential part of all these tests.Otoadmittance investigations show significantly higher baseline values in fluctuant endolymphatic hydrops compared with nonfluctuant Meniere's disease or control subjects. When the hearing improves after dehydration there is a paradoxical increased resistance to the flow of sound energy through the inner ear. Reduced hearing after glycerol is associated with an increase in maximum conductance or a decreased cochlear resistance. Otoadmittance studies on the “normal” ear of patients with “unilateral” Meniere's disease show similar abnormalities and changes.A study of serum levels of immune complexes and complement in patients with Meniere's disease shows elevated levels compared with controls. As yet the significance of this finding is unclear, though it may be related to disease activity.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Ototoxic drugs of the aminoglycoside type have been shown to accumulate to melanin, suggesting a possible mechanism for their ototoxicity. The present study was undertaken by combining electrophysiologic and morphologic methods to investigate whether the ototoxicity of kanamycin is different in pigmented and albino guinea pigs. In pigmented animals a kanamycin dose of 200 mg per kilogram of body weight per day resulted in hearing loss together with loss of both inner and outer hair cells. The albino animals in the same dose group showed significantly less hearing loss and hair cell degeneration. With daily doses of 20 and 60 mg/kg/day, no difference in ototoxicity was found between the pigmented and albino animals. The results support the hypothesis that affinity of kanamycin to inner ear melanin might be responsible for the difference in ototoxicity between albino and pigmented guinea pigs.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

In a previous study we demonstrated an increased ototoxicity in pigmented compared with albino guinea pigs given high doses of kanamycin. In the present investigation using scanning electron microscopy we studied the fine structure of the surface preparation of the organ of Corti to examine whether a qualitative difference in lesion pattern exists between albino and pigmented guinea pigs. Kanamycin was given by daily subcutaneous injections in the amounts of 20, 60, and 200 mg per kilogram of body weight until hearing impairment was noted. No difference in the pattern of degeneration was observed in the albino and pigmented guinea pigs. No giant cilia were seen. The classic gradient of degeneration of the outer hair cells (OHCs), with the most pronounced damage in the first row of OHCs in the basal coil and progressively diminishing lesions in the second and third rows, as observed in both species.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Two of four patients with active stapedial otospongiosis had abnormal filamentous structures in osteoblast-like cells. These structures were rare in these cells and did not occur in any other cells. The structures were 17 nm wide and clustered in a loose skein in dilated cisternae of the rough endoplasmic reticulum. They resembled the nucleocapsids of subacute sclerosing panenecephalitis, a variant of measles virus.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Retrolabyrinthine surgery is done to expose the cerebellopontine angle directly through the ear. It is indicated when the hearing in the ear to be operated upon is useful. The surgical technique entails four steps: complete mastoidectomy, extended posterior exposure of the sigmoid sinus, exposure of the posterior fossa dura, and exposure of the cerebellopontine angle.Retrolabyrinthine exposure of the cerebellopontine angle is indicated in tic douloureux, atypical facial pain, and hemifacial spasm. Recently, this approach has been used for sectioning the vestibular nerve, exploration of the posterior fossa to obtain a diagnosis, subtotal resection of large cerebellopontine angle tumors, and for the treatment of other cranial nerve problems.The histopathologic findings in the temporal bones of two patients who underwent retrolabyrinthine removal of cerebellopontine angle masses were reviewed. In one, subtotal resection of an acoustic tumor was attempted to preserve hearing in the presence of a bilateral tumor, with no adverse effect on the middle or inner ear. In the second, retrolabyrinthine exploration of the cerebellopontine angle was done for primary cholesteatoma, and operative injury to the nonampullated end of the posterior semicircular canal was noted.Retrolabyrinthine subtotal resection of large acoustic tumors is advocated in bilateral cases and in elderly persons to delay the inevitable loss of hearing by decompression and partial removal of the tumor mass. In primary cholesteatoma of the cerebellopontine exploration may be indicated to obtain a definintive diagnosis before surgical extirpation of the disease is planned.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Recurrent facial paralysis is an infrequent problem for the otolaryngologist. This paralysis may be associated with the Melkersson-Rosenthal syndrome, a triad of recurrent facial paralysis, relapsing facial edema, and associated fissured tongue. Most patients do not have the accompanying stigmata of this syndrome. This paralysis may occur unilaterally or bilaterally. The usual sequelae of recurrent facial paralysis are progressive synkinesis and increasing residual paresis with each episode, and total facial paralysis may be the final outcome. Two patients, one with unilateral Melkersson-Rosenthal syndrome and the other with a bilateral recurrent idiopathic facial paralysis, were treated wtih combined transmastoid and middle cranial fossa total facial nerve exposure, decompression, and slitting of the fibrous nerve sheath. Postoperatively they have not suffered from facial paralysis during a follow-up period of three years.It appears that this surgical management safely and effectively prevents recurrent facial paralysis unilaterally or bilaterally, whether or not it is associated with the Melkersson- Rosenthal syndrome. Until further experience with this particular management of recurrent facial paralysis is reported, however, caution should be used in recommending it. Additionally, it should not be assumed from this experience that surgical treatment for idiopathic facial paralysis in Bell's palsy is necessarily implied.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Clinical usefulness of the neodymium/yttrium aluminum garnet (Nd:YAG) laser in surgery of the middle ear is unproven. An animal study was designed to examine the influence of Nd:YAG laser irradiation on cochlear potentials following vaporization of the stapes. Electrocochleagraphic changes were observed in two of the five animals studied, and caution is advised before using this instrument in humans.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Labyrinthectomy is an effective technique in the surgical treatment of vertigo. We believe that the transmastoid approach is the most direct method of vestibular ablation. This technique provides direct visualization of vestibular neuroepithelium and allows for positive identification of the facial nerve. Vertigo was successfully controlled by this method in thirty-seven (97%) of thirty-eight patients.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID