Clinical tutorials: rationale and technique.
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MEDLARS↗
Biomedical subjects
J G Neely
Publications and source records attributed to J G Neely.
Induction of heat shock protein in interdental cells by hyperthermia.
The effect of hyperthermia on induction of the 72 kilodalton (kDa) heat shock protein (HSP72) was examined in interdental cells of the guinea pig cochlea. After being immersed in a water bath of either normal body temperature (37 degrees C, control condition) or 43 degrees C (hyperthermic condition), animals were killed either 0, 1, 2, 6, or 18 hours later. Cochlear sections were incubated with a monoclonal antibody raised against HSP72 and relative staining densities were quantified with a light microscopic image analysis system. Optical densities of the interdental cell region of animals receiving hyperthermia treatment were significantly greater than those of animals in the control group. Further analysis revealed that levels of HSP72 immunoreactivity began increasing by 1 hour after hyperthermia and continued to increase thereafter, to reach maximal levels at 6 hours. The maximal levels were maintained for the rest of the experiment--18 hours. The results indicate that hyperthermia leads to an increase in the synthesis of HSP72 in guinea pig interdental cells.
Animals↗
Computerized quantitative dynamic analysis of facial motion in the paralyzed and synkinetic face.
Diagnosis, treatment, prognosis, and the neurobiology of recovery of facial paralysis has been impeded by the inability to quantitate facial movement objectively. The purpose of this paper is to report our preliminary results in the study of the paralyzed face using a newly developed computerized quantitative dynamic analysis system. Five normal volunteer subjects, and 17 patients with facial paralysis or paresis, from a wide range of etiologies, were analyzed utilizing the computerized analysis system; eight of these patients had synkinesis. Raw data image-change intensity: duration curves, numeric and graphic displays of curve parameter descriptive statistics, and rank order correlation analyses showed high levels of correlation between the computerized facial motion analysis and the House-Brackmann facial nerve grading system and a clinical grading scale for synkinesis. These data suggest that it is possible to develop a computerized image-difference analysis system that approximates the human ability to access facial movement and, additionally, deliver an equal-interval continuous quantitative data scale dynamic over a spectrum of time during facial motion.
Adolescent↗
Detection and localization of heat shock protein 70 in the normal guinea pig cochlea.
Normal guinea pig cochlear sections were treated with an antibody against heat shock protein (HSP70). HSP70-like immunoreactivity was observed in Claudius' cells and in the interdental cells of the spiral limbus. In the organ of Corti, immunoreactivity was confined to pillar cells, as well as Hensen's and Deiters' cells.
Animals↗
Basic hearing tests.
This article contains a discussion of pure-tone and speech audiometry as these measures relate to primary audiologic evaluation of hearing. The scientific foundation underlying the development of stimulus-specific standards for normal hearing, test materials, and methods for basic tests are included. A rationale for test administration, masking, and interpretation of results is presented.
Audiometry, Pure-Tone↗
Lateral temporal bone resections.
Eighteen consecutive patients underwent a lateral temporal bone resection for the treatment of tumors originating in the auricle, the external auditory canal, the periauricular skin, or the parotid and were retrospectively analyzed. The different lateral temporal bone resections performed have been categorized into four types. The type I resection consists of the removal of the tympanic bone and the external auditory canal lateral to the tympanic membrane. The type II resection consists of the removal of the entire tympanic bone, the tympanic membrane, the incus, and the malleus, preserving the facial nerve and the inner ear. Type III resections remove, in addition to the those structures removed in type II resections, the distal facial nerve and fallopian canal, the mastoid tip, the styloid process, and the stylomastoid foramen. The type IV resection consists of the removal of only the mastoid tip and the inferior portion of the tympanic bone. When the techniques of lateral temporal bone resection are used appropriately, adequate surgical treatment of patients with selected advanced and recurrent malignant tumors of the external ear, the periauricular skin, and the parotid is possible with low morbidity and a high probability of local regional control.
Adult↗
Thickness of the lateral surface of the temporal bone in children.
The placement of implantable auditory prostheses in children has raised questions concerning the thickness of the temporal bone in the region of implantation. The purpose of this study is to describe the thickness at specific sites of the lateral surface of the temporal bone in children of different ages. One hundred twenty-five intact temporal bones from 83 children of known sex, race, and age between birth and 20 years were measured. Thickness was measured with a specially designed micrometer at specific locations from a fixed reference point by use of a surface projected grid for site identification. Thickness was plotted against age on scattergraphs for each site, and regression analysis revealed a bimodal linear relationship. Sites medial to the temporalis muscle were the thinnest; sites associated with the posteroinferior insertion of the temporalis muscle, along the supramastoid crest, were the thickest. However, wide interindividual variability was the rule.
Cephalometry↗
Growth of the lateral surface of the temporal bone in children.
The adaptation of implantable auditory prostheses for use in children has raised questions concerning both what effect growth may have on the implant and what effect the implant may have on growth. The purpose of this study is to describe temporal bone lateral surface dimensions in children of different ages to draw inferences about growth rates. Using a surface projected grid and point calipers, 158 intact temporal bones from 103 individuals of known ages between birth and 20 years were measured at six points from a fixed reference. These specimens were located in the skeletal collections of the Smithsonian Institute's Museum of Natural History, the Medical Museum of Walter Reed Hospital at the Armed Forces Institute of Pathology, and the Cleveland Museum of Natural History. Linear regression analysis helped clarify a bimodal pattern of growth in which marked increases in dimension occur from birth to 4 years of age and much less change is seen from age 4 to 20 years. These data suggest that implantation in children under 4 years of age is subject to maximal growth effects.
Adolescent↗
Histologic findings in two very small intracanalicular solitary schwannomas of the eighth nerve: II. "Onion bulbs".
An "onion bulb" is a descriptive histologic term referring to concentric layers of Schwann cell processes about a myelinated nerve fiber. Between the layers of Schwann cells are increased amounts of longitudinally oriented collagen fibers. It is thought that onion bulbs form as a result of sequential segmental demyelination and remyelination attempts. This process can become so severe that the myelinated fiber loses its myelin and ultimately degenerates; however, many fibers remain viable and thinly myelinated. The physiologic effect of "onion bulbs" is to markedly decrease conduction velocity in the fiber affected. In the auditory system, incompletely myelinated cochlear nerve fibers in the infant and in patients with multiple sclerosis show delays of the auditory evoked potential latencies and psychoacoustic retrocochlear patterns. No anatomic substrate has been identified for these auditory tests patterns in the acoustic tumor (solitary schwannoma of the eighth nerve). Two very small intracanalicular acoustic tumors were resected en bloc with the nerve of origin, serially sectioned, stained for neural tissue, and studied by light microscopy. In both tumors, histologic findings consistent with onion bulb formation were discovered about some of the myelinated nerve fibers found deeply incorporated in the tumor mass. These findings suggest that demyelination, perhaps with the formation of onion bulbs, may be a histopathologic correlate for retrocochlear dysfunction seen in acoustic tumors.
Cranial Nerve Neoplasms↗
Panel discussion: The surgical anatomy and fine points of endolymphatic system surgery.
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Ear, Inner↗
Classification of spontaneous cerebrospinal fluid middle ear effusion: review of forty-nine cases.
This article presents a classification system of spontaneous cerebrospinal fluid middle ear effusion to facilitate early diagnosis and lesion localization for surgical correction. Thirty-eight articles containing case histories of 45 patients with spontaneous cerebrospinal fluid middle ear effusion reported in the English literature from 1913 to 1983 were reviewed. Four additional personal cases, representing the largest single series, are described in detail. Classification of these cases into the following three types has been possible: (type I, abnormal connections through the otic capsule; type II, abnormal connections adjacent to the otic capsule; and type III, abnormal connections distant from the otic capsule. The diagnostic and therapeutic implications of each type are unique. Age, auditory and vestibular test results, and computerized or hypocycloidal tomography differentiate the three.
Adolescent↗
Diagnosis and treatment of iatrogenic cerebrospinal fluid leak and brain herniation during or following mastoidectomy.
Iatrogenic brain herniation, with meninges (meningoencephalocele) or without meninges (encephalocele), following mastoidectomy is rare. However, the seriousness of the complication and the potential for its prevention necessitate periodic review and emphasis. In this study, 6 patients with small iatrogenic dural injury during mastoidectomy, 1 patient with postoperative large encephalocele, and 2 patients with three spontaneous meningoencephaloceles are reviewed. These cases, and the literature, support the following: 1. A dural injury is necessary for herniation. 2. If the arachnoid remains intact, a meningoencephalocele results with the potential for cerebrospinal fluid leak into the middle ear and recurrent meningitis. 3. If the arachnoid is not intact, an encephalocele results which presents predominantly as a mass without a cerebrospinal fluid leak. 4. The dura and arachnoid may be torn during mastoidectomy, resulting in an immediate cerebrospinal fluid leak that can go easily unrecognized. Taking time to carefully inspect any area of dural exposure obviates this oversight. 5. A satisfactory technique of tegmen and dural-arachnoid repair in these ten cases is described.
Cerebrospinal Fluid Otorrhea↗
Mechanisms of hearing: cochlear physiology.
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Action Potentials↗
Hearing conservation surgery for acoustic tumors--a clinical-pathologic correlative study.
It has been estimated that hearing conservation is possible in 50% of patients with tumors extending medial to the porus acusticus 1.5 cm or less and who maintain speech discrimination scores of 80% or greater. Others have indicated that a hearing level of 30 dB or less and 80% discrimination are ideal candidates for hearing preservation surgery. Twenty-two cases of solitary schwannoma of the eighth nerve are reviewed in which adequate tissue was available for histologic fiber analysis, using the established preoperative predictive criteria for hearing preservation surgery. We describe the histology found in patients meeting these preoperative criteria. The tumors in ten cases measured less than 1.5 cm; five cases had a discrimination score of 80% or greater; and four cases had a pure-tone average of 30 dB or less. Only three cases satisfied any two criteria and only one case satisfied all three criteria. All cases had significant fiber destruction and tumor infiltration. The one case that met all three criteria demonstrated severe tumor infiltration within the cochlear nerve and the trunk of the eighth nerve; in two of five subserial en block tumor-nerve cross-sections no fibers could be identified crossing the tumor. Histologic data suggests that completely removing the tumor while attempting to preserve hearing may be beyond present surgical capabilities. They further suggest that the present preoperative criteria for selection of patients for hearing preservation are inadequate.
Cochlear Nerve↗
Is it possible to totally resect an acoustic tumor and conserve hearing?
Over the last 19 years there has been increasing interest in the conservation of hearing while acoustic tumors are being resected. As enthusiasm has increased for the conservation surgery, so has controversy. The key to the controversy is a dissociation between gross anatomic and histologic observations. The purpose of this paper is to summarize our laboratory experiments and clinical observations in three areas: (1) Our experiments and observations suggest that it is probably not possible to totally resect an acoustic tumor medial to Scarpa's ganglion and conserve hearing. (2) It has not been possible to predict from preoperative auditory and vestibular function tests the number of fibers present within the cochlear and vestibular nerves lateral to the tumor, nor the number of fibers in small aggregates that may pass the tumor periphery. (3) If microscopic amounts of tumor are left behind, is that significant? It is too early to answer this question.
Hearing Loss↗
Diagnosis and treatment of spontaneous cerebrospinal fluid otorrhea.
Two consecutively operated-on adult cases with spontaneous cerebrospinal fluid otorrhea were reviewed. Three meningoencephaloceles through tegmental defects were found. Each cele was peduculated through a small dural dehiscence partially obstructed by herniated brain. The otic capsule was normal in both cases. Bipolar cautery was used to reduce the size of the meningoencephalocele and to allow this tissue to assist in the closure of the defect. Conchal cartilage was placed through the tegmental defect to act as a self maintaining intracranial repair of the bony dehiscence. These cases and the literature suggest that fistulization of dura is more frequently the cause of spontaneous cerebrospinal fluid otorrhea in adults than is a defect in the otic capsule. Thus, direct surgical inspection of these areas is required.
Adult↗