Sex-related differences in composition of otosclerotic and unafflicted stapes.

This research was undertaken to determine whether stapedial composition could be used to distinguish the sex of patients afflicted with otosclerosis and the sex of unafflicted controls. Energy dispersive-electron probe microanalyses (EDS/EPMA) of otosclerotic stapes from 10 male and 13 female patients were compared with analyses from four unafflicted men and five women. The composition of control stapes differed at p << 0.05 (discriminant analyses) from otosclerotic specimens. Thirteen elements analyzed are in two statistical categories: Group I: Ca, Cr, Fe, Zn, Mg, P, and S; and Group II: Al, K, Mn, Na, Si, and Ti. Elements of Group I distinguish unafflicted men from unafflicted women at a high level of significance (p << 0.05). The same group distinguished afflicted men from otosclerotic women at a lower level (p < or = 0.05), but only if comparisons are based on the single (rather than mean) maximum value of each trace element in each stapes, and only if both Cr and Zn are included in the group. Group I elements also distinguish control versus afflicted men and control versus afflicted women at p << 0.05. Group II elements do not distinguish any of the cohorts mentioned at p < or = 0.05, although they do more successfully classify control and afflicted women as to sex than they do men. They also more successfully predict the diseased status of afflicted men and women than the normal status of controls. The elements whose concentrations exhibit sex-related convergence in otosclerotic stapes are either fundamental constituents of stapedial hydroxyapatite in general or are specific activators of enzymes implicated in otosclerosis. Thus further investigation of the role of metal-potentiated enzymes in the origin of the disorder is warranted.

Composition of the otosclerotic stapes: electron microprobe analyses.

For the first time, otosclerotic stapes have been distinguished from unafflicted controls at a high level of significance by using a spectrum of elements measured by energy-dispersive spectrometer-electron probe microanalyses (EDS/EPMA). Discriminant analyses of the maximum concentration of 13 elements measured at several sites within each of 32 stapes differentiated otosclerotic from unafflicted individuals well above the 95% confidence level. Eight of the 9 control (unafflicted) and 21 of the 23 afflicted stapes were correctly classified. In descending order of contribution to the discriminant function, the elements are Zn > Cr > K > Ca > Si > Mn > Na > Al > Mg > P > Fe > S > Ti. Zinc and chromium account for much of the difference, but discriminant analyses excluding them still distinguish the two groups at the 95% confidence level. These results are consistent with previous reports of high levels of alkaline phosphatase, a zinc-containing enzyme, in afflicted stapes. But the broad spectrum of elements capable of distinguishing otosclerotic stapes warrants study of additional zinc-containing and other metal-containing or metal-activated moieties.

Current diagnosis of acoustic tumors.

This article discusses the most direct and cost-effective means of diagnosing acoustic tumors. The sensitivity and specificity of current diagnostic tests are reviewed. Newer techniques, including magnetic resonance imaging (MRI), have changed the diagnosis of acoustic neurinomas. Our current recommendation is to do a screening auditory brainstem evoked response (ABR) if the neurotologic examination and audiometry indicate a possibility of tumor. If the audiogram and examination indicate a high probability of tumor, we may proceed directly to magnetic resonance scanning.

Transmastoid labyrinthectomy.

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.

Isolated intralabyrinthine schwannoma.

Although most vestibular schwannomas arise in the internal auditory canal, a more peripheral site of origin is possible. We report a case of isolated schwannoma limited to the labyrinthine vestibule. Our description of the location of this tumor is further documentation that schwannomas can arise from the terminal vestibular nerve fibers to the cristae or maculae. Either the nerve roots of the superior vestibular nerve to the utricle and horizontal and superior semicircular canal cristae, or the nerve roots of the inferior vestibular nerve to the saccule and posterior semicircular canal crista may have been the locus of origin of this unusual tumor. Intralabyrinthine schwannoma should be included in the differential diagnosis in the face of progressive auditory and vestibular dysfunction. Because conventional roentgenographic studies usually fail to demonstrate the presence of schwannoma in this location surgical exploration of the labyrinthine vestibule in the presence of unserviceable hearing and incapacitating vertigo is indicated.

An unusual congenital middle ear ossicular anomaly.

Unilateral congenital absence of the stapes suprastructure occurred in association with displaced attachment of the stapedial tendon on an abbreviated incudal lenticular process. The stapes footplate was intact and mobile, and the middle ear was otherwise normal. This is interpreted to be a developmental aberration involving partial absence of a second branchial arch derivative. The preoperative history of no trauma or surgery and the audiologic analysis correlated with the occurrence of this anomaly. This appears to be the first reported case of this unusual congenital anomaly. In addition, it adds a unique item to the differential diagnosis of the pathologic features implicated in an ear with a conductive deficit, intact stapedius reflex, and tympanogram consistent with ossicular discontinuity.

Unilateral complete aplasia of the inner ear with associated tracheoesophageal fistula: report of a case.

A case of unilateral complete aplasia of the petrous apex and inner ear associated with H-type tracheoesophageal fistula is reported. polytomography, computerized axial tomography, and plain film radiography confirmed the presence of this rare variant of inner ear aplasia. This patient, who has normal facial nerve function, is, to our knowledge, the first reported case of a nonthalidomide, Michel-type aplasia since the original report of Michel more than a century ago. Unilateral complete inner ear aplasia associated with tracheoesophageal fistula has not been previously reported.