The Gopen-Yang Superior Semicircular Canal Dehiscence Questionnaire: development and validation of a clinical questionnaire to assess subjective symptoms in patients undergoing surgical repair of superior semicircular canal dehiscence.

OBJECTIVE: To characterise subjective symptoms in patients undergoing surgical repair of superior semicircular canal dehiscence. METHODS: Questionnaires assessing symptom severity and impact on function and quality of life were administered to patients before superior semicircular canal dehiscence surgery, between June 2011 and March 2016. Questionnaire sections included general quality of life, internal amplified sounds, dizziness and tinnitus, with scores of 0-100 points. RESULTS: Twenty-three patients completed the questionnaire before surgery. Section scores (mean±standard deviation) were: 38.2 ± 25.2 for general quality of life, 52.5 ± 23.9 for internal amplified sounds, 35.1 ± 28.8 for dizziness, 33.3 ± 30.7 for tinnitus, and 39.8 ± 22.2 for the composite score. Cronbach's α statistic averaged 0.93 (range, 0.84-0.97) across section scores, and 0.83 for the composite score. CONCLUSION: The Gopen-Yang Superior Semicircular Canal Dehiscence Questionnaire provides a holistic, patient-centred characterisation of superior semicircular canal dehiscence symptoms. Internal consistency analysis validated the questionnaire and provided a quantitative framework for further optimisation in the clinical setting.

Rusty green stained temporal bone associated with exposure to tetracycline: an unusual presentation of black bone disease.

OBJECTIVE: To review the phenomenon and implications of temporal bone and craniofacial bone staining in the context of prolonged exposure to tetracycline antibiotic. METHODS: Case report and literature review. RESULTS: A 52-year-old male with a 5-year history of tetracycline use presented to undergo tympanomastoidectomy and was found to have an unusual rusty green pigmentation of the entire aspect of the exposed temporal bone. A literature review revealed more than 20 cases of tetracycline-induced pigmentation of intraoral maxillary and mandibular bone, and 2 prior cases involving the cranial bones. CONCLUSION: Tissue and organ pigmentation is an unexpected and unfavourable consequence of the use of tetracyclines, particularly minocycline. Tetracycline is contraindicated in children because of the risk for dysosteogenesis and enamel hypoplasia. In adults, although the unusual staining may present as an unexpected dilemma upon surgical exposure, current research shows no significant clinical consequences for this type of pigmentation.

A chromatographic approach to the determination of relative free energies of interaction between hydrophobic and amphiphilic amino acid side chains.

A liquid chromatographic stationary phase was prepared by covalently binding to the surface of microparticulate silica gel functionality (benzylsilane), which mimics the side chain of the amino acid phenylalanine. The chromatographic retentions of the N-acetyl C-(N'-methyl) amides of various hydrophobic and amphiphilic amino acids on this stationary phase were measured using an aqueous mobile phase. A retention order of Gly < Ala < Cys < Val < Met < Pro < Ile < Leu < Tyr < Phe < Trp is seen at room temperature. Chromatographic retentions were used to derive free energies of adsorption of the amino acid derivatives on the chromatographic support relative to that of the glycine derivative. The temperature dependencies of the retention of aromatic and aliphatic amino acid derivatives differ in curvature, indicating a qualitative difference in the absorption mechanism. An adsorption model for retention is proposed, and arguments are made as to the suitability of an adsorption model for describing the contacts between amino acid side chains during the initial steps of protein folding.

Anatomy of the normal human cochlear aqueduct with functional implications.

There is great variation in published descriptions of the shape, size, and patency of the human cochlear aqueduct. The first part of this paper describes the anatomy of the normal human cochlear aqueduct as determined from a study of 101 temporal bones. Nineteen bones aged 0-1 years and approximately 10 bones per decade of life until age 100 years were examined. The aqueduct was found to have a funnel shaped aperture at the cranial end with a dural sheath extending into it for a varying distance. The rest of the aqueduct was filled with a meshwork of loose connective tissue, often with a central lumen within it. Four types of patencies were noted: central lumen patent throughout length of aqueduct (34%), lumen filled with loose connective tissue (59%), lumen occluded by bone (4%), and obliteration of the aqueduct (3%). The mean value (+/- SD) of the narrowest portion was 138 (+/- 58) microns which occurred 200-300 microns from the cochlear end of the aqueduct. There was no correlation between age and narrowest diameter, or between age and category of patency. In the second part of this paper, we propose quantitative models of aqueduct function, based on measurements of ductal dimensions and known acoustical properties of the inner ear. Our model analyses suggest that in normal ears, the aqueduct (1) cannot support fluid flows large enough to explain stapedectomy gushers, (2) does filter out cardiac- and respiration-induced pulses in CSF and prevents them from affecting cochlear function, and (3) has little effect on normal ossicular transmission of sound for frequencies above 20 Hz. In pathological ears, such as those with ossicular disruption or after a type IV tympanoplasty, a patent aqueduct might affect hearing for frequencies below 150 Hz.

A human temporal bone study of acute bacterial meningogenic labyrinthitis.

It is well established that sensorineural hearing loss (SNHL) is an important sequela of acute bacterial meningitis. Previous human temporal bone histopathologic studies have suggested that such hearing loss is due to labyrinthitis. This study involved a detailed and systematic evaluation of the auditory and vestibular end-organs in 41 human temporal bones from patients with acute bacterial meningitis, aimed at describing the spectrum of histopathologic changes within the labyrinth, ascertaining likely routes for spread of infection from the meninges to the inner ear, and comparing the data from humans with those described in a rabbit model of meningogenic labyrinthitis. Our study revealed the following: (a) Suppurative labyrinthitis occurred in 20 (49%) bones. Of these 20 bones, the cochlea was affected in all, whereas the vestibular organs were involved in 10. Eosinophilic staining of inner ear fluids without the presence of inflammatory cells (so-called "serous" labyrinthitis) occurred in 14 of the remaining 21 bones. This staining occurred primarily within the vestibular system. Its significance and pathogenesis remains unknown; (b) Sensory and neural structures of the inner ear appeared intact in the majority of specimens, including bones with suppurative labyrinthitis and those with eosinophilic staining of inner ear fluids. This finding raises the possibility of preventing or reversing SNHL by therapeutic intervention. Spiral ganglion cells were severely degenerated in 12% of bones, indicating a retrocochlear site of hearing loss in addition to the cochlea. This subset of patients may perform poorly after cochlear implantation; (c) It has been traditionally assumed that irreversible and permanent SNHL is caused by suppurative labyrinthitis, whereas reversible SNHL is caused by serous labyrinthitis. Our findings question the validity of these assumptions; (d) The data were consistent with the hypothesis that both the cochlear modiolus and cochlear aqueduct can serve as potential pathways for spread of infection from the meninges to the inner ear; (e) There were many similarities in the histopathology of the inner ear in humans when compared with the rabbit model of meningogenic labyrinthitis. A notable difference was that the cochlear aqueduct appeared to be the sole pathway for spread of infection in the rabbit, whereas in the human, both the modiolus and aqueduct were possible pathways.