Otolaryngology and head and neck surgery最新文献

Fifteen infants at risk for sudden infant death syndrome by clinical criteria were tested using brain stem auditory evoked potential (BAEP) techniques. All infants demonstrated abnormalities on two or more of the seven criteria employed to assess results. The data indicate that BAEP testing may play a significant role in the identification and monitoring of these children.

Generators of the frequency-following response (FFR) were assessed in 13 guinea pigs by cooling of the whole body and by experimental lesions of the brain stem. In the temperature study, the amplitude-temperature function of the FFR contained a significant cubic component that was absent from that of the cochlear microphonic potential (CM) recorded from the round window. The phase shift of the FFR increased with decreasing body temperature. In experimental lesions of the brain stem, a significant phase shift of the FFR was obtained following contralateral postcollicular section. The FFR amplitude with transection of the auditory nerve was similar to that found before surgical sections of the brain stem. The duration of the FFR after the transection corresponded precisely to that of the round window CM. These results indicate that the origin of the FFR contains both nonneural (ie, cochlea) and neural (ie, involving the inferior colliculus) generators.

Histiocytosis X is characterized by a proliferation of cytologically benign histiocytes and occurs in a severe form (type 1) with a short course and poor prognosis and a milder form (type 2) with a protracted course and favorable prognosis. Otolaryngologists will encounter the type 2 form of the disease and must include it in the differential diagnosis of osteolytic lesions of the skull.

Bromate has not been regarded as an ototoxic drug. Potassium bromate, marketed as a neutralizer in home permanent cold wave hair kits, has caused several cases of accidental poisoning in children, resulting from the ingestion of this solution. Two cases of hearing loss following ingestion of this solution for the purpose of suicide have been reported here and in the literature review.

Increasingly aggressive surgical attack upon disease in and about the base of the skull will continue to produce various combinations of deficits of the 8th through 12th cranial nerves. Although isolated paralyses of these nerves usually can be managed with little difficulty, various combinations of paralyses can result in loss of airway, voice, or swallowing functions that are challenging to the head and neck surgeon. A thorough understanding of the disordered physiologic conditions that these lesions can produce, coupled with a logical medical and surgical approach to their management, may result in better rehabilitation of these patients.

Five cases of carotid artery lesions at the skull base or temporal bone, treated surgically, are presented. These lesions include mycotic aneurysms and carotid stenosis secondary to angiofibroma and a glomus caroticum. One case demonstrated an anomalous carotid anatomic pattern with a persistent stapedial artery. A description is provided of the technique of subtotal petrosectomy with permanent anterior displacement of the facial nerve, and middle ear obliteration, thus achieving a safe exposure of the temporal course of the internal carotid artery. The cases indicate that cooperation between temporal bone surgeons and vascular surgeons is a prerequisite to successful repair of such lesions, as good recovery in all five cases was achieved. The techniques allow maintenance of carotid flow during and after repair, reducing the potential for neurologic complications or mortality.

An animal model for pneumococcal otitis media was studied histologically at varying intervals postinoculation. Histologic changes generally associated with acute inflammation (edema, diffuse infiltration with polymorphonuclear leukocytes, and hemorrhage) occurred early in the disease while the ears were culture positive. Changes generally associated with chronic otitis media (lymphocyte infiltration and osteoneogenesis) occurred later in the course of the disease when the ears were culture negative. Metaplasia of middle ear mucosa and middle ear granulation tissue were observed as early as five days following inoculation. Middle ear granulation tissue was identified in 82% of all cases; cholesteatoma was seen in only one ear. Tympanic membrane perforation did not occur. Labyrinthitis and endolymphatic hydrops were fairly common findings. The former was identified in 56% of ears examined, and the latter, in 45%. These two conditions coexisted in 34% of ears studied, while endolymphatic hydrops alone occurred in 11%.

When the mastoid cavity infection is the result of breakdown of the skin lining, the cavity should be obliterated. Many types of material have been used, but postauricular tissue has been most effective. Instead of a pedicled flap, a free graft of tissue is recommended because it allows better placement of the graft deep into the cavity. It undergoes a more uniform contracture and does not tend to pull out of the depths of the cavity. The principle of obliteration is not only to obliterate the cavity but also to bring a layer of vascularized subcutaneous tissue between the skin lining and the bone.

Primary cholesteatoma of the petrous apex is an uncommon congenital lesion that is suspected clinically by such indirect methods of examination as conventional and tomographic radiology, computerized axial tomographic scan, and angiography. If these indirect methods indicate a petrous apex lesion, the area should be investigated by biopsy through the sphenoid, middle fossa, or translabyrinthine routes. Tumor extension, sphenoid pneumatization, and normal labyrinthine function are factors that determine the surgical approach. Once a diagnostic surgical procedure confirms the presence of an epidermoid cyst at the petrous apex, permanent fistulization through the sphenoid or the middle ear is recommended as definitive management.

Total surgical excision of a glomus jugulare tumor is the treatment of choice for this benign tumor. If the tumor has extended beyond the temporal bone into the intracranial spaces, most often the posterior fossa, the surgical excision becomes more difficult. If the tumor has extended anteriorly and posteriorly into the posterior fossa or if a portion of the tumor is exposed in the external auditory canal with the concurrent infection that is seen with this presentation, the intracranial portion of the tumor should be removed as a first step in a planned two-stage removal of the tumor. If the intracranial extension is limited and there is no infection present with the tumor, a combined otologic-neurosurgical approach using transtemporal and suboccipital access to the temporal bone will allow successful total removal of the tumor in a one-stage procedure. Details are presented to demonstrate this combined otologic and neurosurgical approach to large glomus tumors with intracranial extension.