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Biomedical subjects

A F Jahn

Publications and source records attributed to A F Jahn.

At least 19 recordsLinked to original sources
PubMed1996

Semon's law revisited: an electromyographic analysis of laryngeal synkinesis.

Felix Semon's fascination with vocal fold paralysis led to his theory attributing medialization to isolated abductor paralysis. Later, the Wagner-Grossman hypothesis explained the vocal fold position on the basis of cricothyroid muscle activity. Other authors since that time have dispelled the notion of a role for the cricothyroid muscle in vocal fold position with paralysis. Utilizing laryngeal electromyography, several authors have found electrical activity suggestive of variable reinnervation and synkinesis. This current study included patients with persistent vocal fold immobility. Fourteen patients were studied: half with good voice and half with poor voice. The patients with good voice had a relatively normal arytenoid position and evidence of synkinesis. The group with poor voice had an arytenoid that tipped into the laryngeal inlet and had denervation or poor reinnervation. This suggests that the medialization and upright position of the arytenoid is due to synkinesis.

Electromyography↗
PubMed1994

Osteoma of the internal auditory canal. Case report and literature review.

Osteomas of the internal auditory canal are rare lesions, with only 12 reported cases in the world literature. Symptoms are those of eighth nerve compression, and include unilateral hearing loss and vestibular weakness, thus mimicking symptoms of acoustic neuroma. We report a patient with an osteoma of the internal auditory canal, along with a review of the literature. We note age and sex characteristics from the literature, give evidence of localized trauma as a possible etiologic factor for this lesion, and discuss the pitfalls of relying exclusively on magnetic resonance imaging in the workup of suspected retrocochlear lesions.

Female↗
PubMed1994

Menière's disease: diagnosis and management.

Ménière's disease is an inner ear disorder manifesting as attacks of vertigo, hearing loss, tinnitus, and aural fullness. Successful management includes an accurate diagnosis, ruling out other causes of vertigo, salt restrictions, and use of diuretics.

Adolescent↗
PubMed1993

Neonatal respiratory distress: sequela of bilateral nasolacrimal duct obstruction.

Neonatal respiratory distress is a commonly seen entity whose causes are legion. Nasal obstruction secondary to intranasal masses is significant because neonates are obligate nasal breathers. Congenital nasolacrimal duct obstruction (NLDO) causing respiratory distress is an extremely rare event since most cases of NLDO do not compromise the nasal airway. We report two cases of neonatal respiratory distress secondary to bilateral NLDO with cystic mucocele formation and intranasal extension; only two similar cases have been previously described. Pertinent embryology and anatomy are reviewed as is a brief discussion of congenital NLDO. MRI and a nasal endoscopic photograph are provided demonstrating the nasolacrimal and nasal pathology. Treatment strategies are outlined. Consideration of nasolacrimal duct pathology in the differential diagnosis of neonatal respiratory distress and nasal obstruction is stressed.

Female↗
PubMed1993

Traumatic pneumomediastinum in a child secondary to corn chip perforation of the esophagus.

Esophageal perforations, while an infrequent form of trauma in the pediatric population, are of concern because of their life-threatening complications. If not recognized and treated promptly, esophageal injuries can result in mediastinitis and death. An unusual case is presented, describing traumatic esophageal perforation in a child resulting from laceration by an ingested corn chip. A study is reported investigating the rigidity of three types of these popular snack chips. Stress testing and statistical analysis of the resultant measurement data indicated that the three brands of chips were equally rigid. The mean force of compression required to fracture the chips was approximately three pounds, a force great enough to damage the fragile structures of the upper aerodigestive system. Physicians and parents alike should be aware of the possible dangers of this type of snack food to avert the possibility of esophageal injury with its resultant morbidity and potential mortality.

Child↗
PubMed1993

Middle ear ventilation with HydroxylVent tube: review of the initial series.

Thirty HydroxylVent tubes were implanted in twenty-seven patients. The chief indications were unresolving eustachian tube dysfunction, with either collapse or perforation of the tympanic membrane. Every patient had undergone a lengthy course of treatment with conventional ventilation tubes. Twenty ears (66%) showed good results, with prolonged ventilation and restoration of middle ear function. Two tubes appeared to be open, with the development of a pinpoint perforation of the drum. Eight tubes occluded as a result of displacement of the tube, middle ear pathology, or debris. Indications and techniques of management are discussed, along with an analysis of complications.

Adolescent↗
PubMed1993

Biointegrated ventilation tube: current status and new developments.

The biointegrated (HydroxylVent) ventilation tube has been used over the past 3 years in a variety of clinical cases. The chief indication for its use is unresolving eustachian tube dysfunction and failure of more conventional medical and surgical therapy. The surgical technique and a postoperative management are described. New directions in clinical research include a larger lumen prosthesis and a compound prosthesis of hydroxylapatite with Teflon lining.

Child↗
PubMed1992

Experimental applications of porous (coralline) hydroxylapatite in middle ear and mastoid reconstruction.

Hydroxylapatite is a ceramic implant material which has been extensively investigated in the orthopedic and oral surgical literature. A set of animal experiments was carried out to determine the feasibility of the use of porous (coralline) hydroxylapatite for middle ear and mastoid reconstruction. Coralline hydroxylapatite was placed in the mastoid bulla of dogs and was carved into struts which were placed into the middle ear and against the tympanic membrane. Coralline hydroxylapatite is a highly biocompatible material which showed abundant ingrowth when in contact with host bone. There was also good soft-tissue ingrowth and fibrous tissue fixation within the middle ear and against the tympanic membrane. Hydroxylapatite is generally accepted to be osteoconductive, but not osteogenic. However, one of the specimens described with chronic inflammatory mucosal changes, shows de novo new bone formation within the pores of the graft. While normally the bone formed in coralline hydroxylapatite is secondary (lamellar), in this specimen primary (woven) bone was found. Porous (coralline) hydroxylapatite appears to be an excellent otologic graft material. It biointegrates with the host, is osteoconductive, and under certain circumstances may be osteogenic.

Animals↗
PubMed1992

Small fenestra stapedotomy: technique and results.

Small fenestra stapedotomy can improve hearing, improve speech discrimination, and reduce the associated risks of conventional stapedectomy. The authors discuss the advantages and disadvantages of small fenestra, as well as the results of their own stapedotomies.

Adolescent↗
PubMed1991

Chronic otitis media: diagnosis and treatment.

Very few problems are as frustrating as persistent otitis media and the draining ear. The draining ear may present in a variety of ways and may persist despite the use of routine otic drops and oral antibiotics. This article addresses the medical and surgical options available in the management of otitis media and its complications.

Anti-Bacterial Agents↗
PubMed1991

Sudden hearing loss due to AIDS-related cryptococcal meningitis--a temporal bone study.

We have presented the clinical history and temporal bone findings in a patient who manifested sudden hearing loss, and who subsequently was found to have cryptococcal meningitis associated with AIDS. The histopathologic findings are similar to earlier reports in patients without AIDS. Because cryptococcal infection is so much more common in AIDS patients than in the general population, it must be considered a causative factor when presented with an AIDS patient with progressive or sudden hearing loss. This offers the patient a chance for timely and effective treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1991

A biointegrated hydroxylapatite ventilation tube for definitive treatment of chronic eustachian tube obstruction.

A dense hydroxylapatite ventilation tube has been designed for the purpose of providing prolonged ventilation of the middle ear. The tube is placed beneath the fibrous annulus of the eardrum, into a groove within the bony annulus and canal. The device takes advantage of the documented biocompatibility of hydroxylapatite to achieve biointegration with the soft tissues of the fibrous annulus, drum, and canal skin, as well as the bone of the deep ear canal. The tube does not appear to cause a foreign body reaction, and does not seem to extrude over time. The device is proposed for patients with unresolving eustachian tube obstruction who require a permanent tympanic stoma for normal middle ear function.

Biocompatible Materials↗
PubMed1989

MRI findings in two cases of acute facial paralysis.

This article describes the use of magnetic resonance imaging (MRI) in the evaluation of the facial nerve paralysis of Bell's palsy and herpes zoster oticus. Identification of the nature of inflammatory facial nerve paralysis often presents a diagnostic dilemma. The site of involvement along the course of the nerve may have importance when treatment options are being considered. We have found MRI to be a unique method for localizing the site of nerve injury in both Bell's palsy and Ramsay Hunt syndrome.

Adult↗