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Biomedical subjects

F H Linthicum

Publications and source records attributed to F H Linthicum.

At least 109 records · Page 6Linked to original sources
PubMed1985

Congenital atresia of the external auditory canal.

Children with congenital atresia of the external auditory canal require an early assessment of hearing and a determination of the degree of atresia and associated pathology by polytomography and/or high-resolution CT scanning. We analyzed the otologic findings in 302 ears (239 patients) with severe atresia of the external auditory canal. Eighty-seven primary or revision surgeries were performed. Fifty-three percent obtained a residual conductive deficit of 20 dB or less. Lateralization of the tympanic membrane graft was the primary cause of failure in obtaining good hearing results. The use of split-thickness skin graft instead of a full-thickness skin graft to cover the reconstructed external canal has decreased the incidence of restenosis and revision surgery.

Abnormalities, Multiple↗
PubMed1985

Residual high-frequency hearing in a patient with Mondini's deformity: clinical implications.

We reviewed records of a patient with Mondini's deformity who had hearing loss in the speech frequencies and preservation of hearing for frequencies above 4000 Hz. The patient seemed to be an example of a profoundly deaf child with good speech development secondary to preservation of ultra-audiometric hearing. We suggest that patients with Mondini's deformity have their ultra-audiometric hearing evaluated, and that those with profound deafness and ultra-audiometric hearing be radiographically evaluated to rule out Mondini's deformity for diagnostic and therapeutic purposes.

Auditory Threshold↗
PubMed1985

Labyrinthine ossification: differences between two types of ectopic bone.

We found histologic differences between two types of ectopic bone in the labyrinthine spaces of seven temporal bones from patients with various surgical procedures and diseases. Metaplastic bone, which originates from scar or connective tissue, is cellular, is not eosinophilic, and does not have lamellae, osteoblasts on the surface, or sharp margins. Osteoplastic bone, which originates from adjacent bone capsule, is not cellular but is eosinophilic and has lamellae, osteoblasts on the surface, and sharp margins. Surgical interference within the blood supply to the inner ear was responsible for metaplastic bone, and damage to the endosteum by surgery or disease caused osteoplastic bone. We assume that endosteum damage during cochlear implant surgery plays a role in osteogenesis.

Choristoma↗
PubMed1984

Otosclerosis and otospongiosis: clinical and histological comparisons.

The simultaneous occurrence of otosclerosis and otospongiosis in the same lesion is well documented. The logical sequence of events would seem to be softening and destruction of the bone by the otospongiotic lesion, which is subsequently converted to otosclerosis. Examination of 46 temporal bones has led us to further classify the lesion as: 1. an active lesion, both otospongiotic and otosclerotic, 2. an inactive lesion, also both otosclerotic and otospongiotic, or 3. a fibrous lesion. Hyalinization of the spiral ligament only occurs adjacent to active otospongiotic or very large otosclerotic lesions. If the lesion adjacent to the spiral ligament is inactive, there is no hyalinization. It seems illogical that a hyalinized spiral ligament will return to normal when the lesion changes from active otospongiosis to inactive otosclerosis. Otospongiotic and otosclerotic lesions are found side by side at the periphery of lesions, and both are adjacent to normal bone. These findings have implications concerning the mode of action of sodium fluoride and other medications that are under evaluation for the control of the sensorineural hearing loss due to otosclerosis.

Aged↗
PubMed1983

Membranous ruptures in Meniere's disease: existence, location, and incidence.

Whether or not attacks of Meniere's disease are related to ruptures in the membranous labyrinth is still a point of contention. To help clarify this point, we used light microscopy to study the membranous labyrinth in 14 temporal bones with hydrops from patients with Meniere's disease, four bones with hydrops from patients without Meniere's disease, and 11 normal bones. Findings suggest that ruptures are specific to bones with hydrops from patients with Meniere's disease and that they occur more frequently in Reissner's membrane than in the vestibular membranes.

Ear, Inner↗
PubMed1983

Otosclerosis: relationship of spiral ligament hyalinization to sensorineural hearing loss.

The sensorineural component of a mixed hearing loss due to otosclerosis is generally accepted as due to the otosclerotic lesion. The existence of pure cochlear otosclerosis without stapes fixation has been questioned. However, we are documenting 7 such cases in a separate publication. Results of this study, which evaluates 46 temporal bones with clinical or cochlear otosclerosis, demonstrate that the degree of sensorineural loss is directly related to the amount of hyalinization of the spiral ligament. The hyalinization occurs adjacent to active otospongiotic lesions but not next to inactive otosclerotic lesions. Both types of lesions may involve the cochlear endosteum. Small channels through the endosteal bone from the lesion to the spiral ligament have been found. The hyalinization spreads laterally from these channels. The hyalinization is presumably a result of the passage of toxic substances (proteolytic enzymes) from the lesion to the ligament. Strial atrophy is most pronounced on ligaments with the greatest degree of hyalinization. Hyalinization in only one ear produces decreased hearing compared to the other ear.

Cochlea↗
PubMed1983

Tissue reaction to prosthetic materials in human temporal bones.

We studied tissue reaction to polymeric silicone (Silastic), polyethylene, tantalum wire, and polytetrafluorethylene (Teflon) in temporal bones and to Silastic in removed shunt tubes. A purpose of this study was to determine which synthetic material is best for insulation of cochlear implant electrodes. We found fibrous tissue around all shunt tubes and in all bones, giant cells in some specimens, and lymphocytic infiltration in a few. We consider none of these findings to indicate bioincompatibility, except in one case with a presumed idiosyncratic reaction to Silastic. We conclude that all four materials are well tolerated by the human ear. Our finding that Silastic is well tolerated for long periods of time leads us to conclude that it is good choice for insulation for implanted wires.

Biocompatible Materials↗
PubMed1983

The effect of stapedectomy on hearing of patients with otosclerosis and Meniere's disease.

To determine new guidelines for stapedectomy in patients with both Meniere's disease and otosclerosis, we studied the position of the saccular membrane and Reissner's membrane in relation to the stapes footplate in eight temporal bones from patients with Meniere's disease. We also reviewed charts of four patients with both otosclerosis and Meniere's disease who had stapedectomy. Histologic and clinical findings were compared with preoperative bone conduction levels at 500 Hz and at high frequencies. We found that the saccular and Reissner's membranes did not contact the stapes footplate ain bones of patients with preoperative bone conduction levels of 35 dB or better at 500 Hz and no high-frequency loss. We also found that stapedectomy was successful in patients with the same criteria. We therefore conclude that stapedectomy does not increase the risk of sensorineural hearing loss for patients with otosclerosis and Meniere's disease who have bone conduction levels of 35 dB o better at 500 Hz and no high-tone loss, but it is contraindicated for patients with 45 dB at 500 Hz or worse and with high-tone loss.

Hearing Loss, Sensorineural↗
PubMed1982

Middle ear effusion in children: a report of treatment in 500 cases.

Records were studied of 500 children younger than 9 years of age with middle ear effusion who had received one of three treatment strategies: (1) administration of medication, including decongestants, antihistamines or antibiotics (or a combination), (2) administration of medication for a limited time and then surgical therapy if effusion did not resolve or (3) myringotomy done immediately with insertion of ventilation tubes and, in some cases, removal of adenoids. Early surgical intervention resulted in significantly shorter delay in hearing restoration. It did not result in a lower recurrence rate and it did not reduce the number of occasions when thick fluid, as compared with thin fluid, was found at operation. Four children for whom medical and surgical treatment failed were considered candidates for mild gain, low maximum-power-output hearing aids. All other children had normal hearing after treatment. Medication was successful in achieving this goal in 48 percent of the cases.

Child↗
PubMed1982

Acoustic tumor surgery with preservation of hearing. A histopathologic report.

The goals of acoustic tumor surgery are total tumor removal, intact facial nerve function, and preservation of hearing. the middle fossa approach offers the opportunity to achieve these goals in selected cases. This article presents the findings from the temporal bones of two patients who had undergone middle fossa removal of an acoustic tumor, nine and ten years before their deaths. Hearing was preserved in one case and lost in the other. The patient with profound postoperative deafness showed severe degenerative changes and ossification in the membranous labyrinth. This was explained on the basis of internal auditory artery occlusion. The goals of acoustic tumor surgery are discussed in light of the histopathologic findings in these two cases. the middle fossa approach is advocated as the best available to achieve these goals in intracanalicular tumors.

Audiometry↗
PubMed1980

Labyrinthine ossificans and cochlear implants.

We report two clinical and five histopathological examples of labyrinthitis ossificans and discuss the possible cause of this condition. Diagnosis can be established by polytomography. The advent of the cochlear implant makes ossification of the cochlea (labyrinthitis ossificans) of more than academic interest, since it requires alteration of the insertion of an electrode into the scala tympani and minimizes the chances of successful stimulation. Hearing losses due to meningitis, advanced cochlear otosclerosis, and trauma are likely to be due to cochlear ossification. Therefore, it is important to rule out this condition by means of polytomography in individuals being considered for cochlear implant surgery.

Adult↗
PubMed1980

Bilateral acoustic tumors. A diagnostic and surgical challenge.

Bilateral acoustic tumors present problems not only in diagnosis but in surgical correction as well. The usual auditory findings associated with acoustic tumors occur late in the development of these lesions. Although vertigo usually is not a complaint, electronystagmographic caloric vestibular tests often show reduced or absent responses bilaterally. In contrast to unilateral-type tumors, bilateral tumors are invasive. Thus, total removal often is not accomplished. However, it is our suspicion that the interruption of the blood supply to the residual tumor causes it to remain dormant.

Adolescent↗
PubMed1980

Pathology of congenital syphilitic labyrinthitis.

An alarming increase in the incidence of syphilitic labyrinthitis has prompted us to review the pathology of this condition. The temporal bones of two patients with congenital syphilis of the ear were studied histopathologically. They showed diffuse osteitic changes in the otic capsule associated with severe hydrops and degeneration of the membranous labyrinth. The posterosuperior wall of the external auditory canal as well as the auditory ossicles showed numerous connective tissue filled spaces surrounded by thin bony trabeculae. These lesions probably represent healed luetic osteitis. There was severe degeneration of the sensorineural structures in the cochlea. A finding of particular interest was the infiltration and fibrous obliteration of the ductus endolymphaticus in both cases. The significance of these findings in relation to the pathophysiology and treatment of syphilitic labyrinthitis is emphasized.

Bone Resorption↗
PubMed1980

Pathologic correlates of electronystagmographic tracings.

Electronystagmographic tracings were correlated with the histopathologic findings in the peripheral vestibular system of 66 temporal bones of 34 patients who complained of dizziness. Although some findings (e.g., spontaneous nystagmus, unilaterally reduced caloric response, and directional preponderance) seemed to have doubtful value in localizing vestibular system disease, other findings indicated a peripheral site of the vestibular lesions. Bilaterally reduced or bilaterally absent caloric responses were consistently associated with pathologic changes in the peripheral vestibular system. Similarly, a unilaterally absent caloric response consistently indicated peripheral disease. On the other hand, positional nystagmus and bilaterally equal caloric responses seemed to indicate the absence of a peripheral site of disease in the vestibular system. Although there is no reliable way to differentiate end organ from vestibular nerve lesions, the latter were more commonly associated with positional nystagmus and absence of a caloric response. The direction of nystagmus beating correlated with the side of the diseased peripheral site in two of four patients with spontaneous nystagmus, in five of seven with positional nystagmus, and in all with unilateral reductions in or absence of caloric responses. Electronystagmographic findings in the present study seemed to reflect diffuse rather than localized pathologic changes in the peripheral vestibular system.

Adolescent↗