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PubMed1987

Flow cytometric DNA analysis of malignant lymphomas with primary bone manifestation.

Malignant lymphomas with primary skeletal manifestation have received controversial evaluation with regard to histological classification and histogenesis. Recent histological and immunohistological studies on the rare bone lymphomas conducted by our team, have shown that they do not differ from primary nodal lymphomas with regard to the spectrum of histological subtypes. The present flow cytometric DNA analysis of paraffin-embedded material from 17 lymphomas documented in the Bone Tumor Registry of Westfalia yielded the following distribution pattern of DNA ploidy: among 12 non-Hodgkin's lymphomas (NHL) (according to the Kiel classification) there was only 1 case of low grade malignancy; this centroblastic-centrocytic lymphoma showed a unimodal diploid DNA histogram. Of 11 highly malignant NHL, 6 were DNA hyperdiploid. Among the 5 cases of Hodgkin's lymphoma, 4 were DNA diploid, (1 nodular sclerosing, 3 mixed types) and one DNA tetraploid (lymphocytic depletion type). Comparison with data from the literature reveals that even with regard to DNA ploidy, malignant lymphomas primarily manifesting in bone do not differ from those of exclusively nodal manifestation.

Bone Neoplasms↗
PubMed1983

Sensorineural hearing loss in posttraumatic incus dislocation.

In 34 posttraumatic incus dislocations, the initial sensorineural hearing loss (primary) after the trauma and that 11 years after trauma (late) were analyzed. Primary hearing loss measurements following the trauma showed that 53% of patients had sensorineural hearing loss of more than 10 dB for at least one of the frequencies from 1,000 to 4,000 cps, 18% for more than 30 dB. For late hearing loss after the trauma, the corresponding percentages were 50% and 15%, respectively. No reliable progression of the posttraumatic sensorineural hearing loss was found, although a few exceptions were seen. It may be concluded that sensorineural hearing loss is not a progressive disorder of the inner ear.

Adolescent↗
PubMed1998

Distortion products otoacoustic emissions in diagnosis of hearing loss in Down syndrome.

This study was carried out to investigate the features of hearing impairment in subjects with Down syndrome. Forty-seven children and 14 adults with Down syndrome were included in the study. In all cases, a complete otorhinolaryngological examination was performed, followed by audiological assessment. Depending on age, intellectual level and middle ear status the following examinations were performed: pure-tone 'play audiometry', tympanometry, acoustic reflex, auditory brain response (ABR) and distortion products otoacoustic emissions (DPOAE). The results were compared with age matched control groups. Among the group of children with Down syndrome, we have frequently found impairment of the conductive function of the middle ear which was expressed by pathological tympanometry. Tympanometry of B and C type was detected in 56% of ears. The amplitude of DPOAE was lower in children with Down syndrome than in the control group. This difference was more expressed in adults with Down syndrome. DPOAE examination results in subjects with Down syndrome without conductive hearing loss indicate early age related inner ear impairment.

Acoustic Impedance Tests↗
PubMed1996

Effects of earmold type on ability to locate sounds when wearing hearing aids.

OBJECTIVE: To determine whether the choice of earmold type can affect aided auditory localization. HYPOTHESES: 1) for sensorineural hearing losses with good low-frequency hearing (Low group, n = 10), the use of open earmolds could avoid decrements in horizontal plane localization found with closed (occluding) earmolds; 2) for sensorineural losses with good high-frequency hearing (High group, n = 12), the use of open earmolds could result in better vertical plane localization than could the use of closed earmolds; and 3) for conductive/mixed hearing losses (CM group, n = 19), the choice of earmold type-hard short, soft short, or soft long-could affect aided localization. DESIGN: Aided and unaided auditory localization was tested for the above three groups of hearing-impaired listeners when wearing bilaterally fitted hearing aids. RESULTS: For the Low group, results were inconclusive because nine listeners showed virtually perfect horizontal localization with both closed and open earmolds. For the High group, two listeners showed improved vertical plane localization with open earmolds. These were the only listeners with HTLs of 30 dB or better at 6000 Hz and 8000 Hz. For the CM group, aided horizontal plane localization was significantly better than unaided localization for about half of the listeners and was similar for the other half. There was no significant group difference for the three earmold types. For some individuals, one earmold type was better than the others. CONCLUSIONS: The choice of earmold can effect aided localization, but the specific effects need further elucidation. Audiologists should be aware that people with conductive or mixed hearing losses may have poor auditory localization and that this may be improved by the fitting of hearing aids.

Bone Conduction↗
PubMed1991

The influence of model parameters on the inverse solution based on MEGs and EEGs.

The influence of parameters describing the head on the localization of two simultaneous active dipoles is studied. The head is described by a set of five concentric anisotropic spheres. The uncertainties in the conductivity parameters and their effects on the dipole parameters are discussed. Finally the applicability of EEG and MEG is compared.

Adult↗
PubMed1996

State of the art on the development of the implantable hearing device for partial hearing loss.

This article summarizes the state of the art of the implantable hearing devices for partial hearing loss. Devices such as temporal bone stimulators and piezoelectric and electromagnetic middle and inner ear transducers are discussed. Cochlear implants are excluded. (See "Update on Cochlear Implantation" in this issue.) Those readers interested in a more in-depth study of implantable hearing devices should consult the February 1995 issue of The Otolaryngologic Clinics of North America which is dedicated to this matter (Guest Editor: Anthony J. Maniglia, MD).

Bone Conduction↗
PubMed1986

Hearing improvement after stapedectomy: up to 19 years' follow-up period.

The long-term results of 925 stapedectomies were analysed after a mean follow-up period of 15 years. Patients who had the operation before the age of 30 were analysed separately. The entire group deteriorated by an average of 0.91 dB/year at 500-2000 Hz, while the under-30 group deteriorated by 0.67 dB/year. There were but slight differences in the conductive component, considering frequencies and age. The perceptive loss/year was not far from that in a normal population.

Adolescent↗
PubMed1997

Hearing loss (in nonoperated ears) in relation to age in osteogenesis imperfecta type I.

Hearing loss was studied in relation to age in nonoperated ears in a group of 142 subjects with autosomal dominant osteogenesis imperfecta type I, which was compared to that in a random subsample of 70 subjects. In the n = 142 group, particularly below the age of 30 years, considerable selection (ie, for ear surgery) had occurred on hearing loss. The hearing threshold increased gradually with age. A hearing loss of greater than 30 dB (Fletcher index) was observed for 51% of the subjects older than 20 years and younger than 60 years. The median hearing loss progressed from the 10th to the 45th years of life with an average annual threshold increase (ATI) of 1 dB/y (0.5 to 4 kHz) up to 1.7 dB/y (8 kHz). Sensorineural loss accounted for 0.6 dB/y ATI at 0.5 to 4 kHz and 1.3 dB/y ATI at 8 kHz; conductive loss accounted for 0.4 dB/y ATI at all frequencies.

Adolescent↗
PubMed1990

Early alterations of cochlear function in experimental perilymph fistulas.

Alterations of cochlear function secondary to perforation of the round window membrane in guinea pigs were expected to reveal sensitive and/or specific audiometric parameters in perilymph fistulas. A perforation of the round window membrane either did not affect acoustic compound action potential thresholds, or induced a delayed, possibly conductive, inner ear hearing loss. Also, evoked suprathreshold responses deteriorated progressively and independently of the increase of compound action potential thresholds. A sudden (conductive) hearing loss and a poor response to suprathreshold stimulation might indicate inner ear damage secondary to a perilymphatic fistula.

Animals↗
PubMedDate not supplied

Superior Canal Dehiscence Syndrome.

The Superior Canal Dehiscence Syndrome (SCDS) was first reported by Minor at. Al. (1998), and has been characterized by vertigo and vertical-torsional eye movements related to loud sounds or stimuli that change middle ear or intracranial pressure. Hearing loss, for the most part with conductive patterns on audiometry, may be present in this syndrome. We performed a literature survey in order to to present symptoms, signs, diagnostic and therapeutic approaches to the SCDS, also aiming at stressing the great importance of including this syndrome among the tractable cause of vertigo. We should emphasize that this is a recent issue, still unknown by some specialists. The Correct SCDS diagnosis, besides enabling patient treatment, precludes misdiagnosis and inadequate therapeutic approaches.

Acoustic Stimulation↗
PubMed1989

Clinical results with a percutaneous bone-anchored hearing aid.

During a 2-year period ending in July 1987, nine patients were implanted with a percutaneous bone-anchored hearing aid developed at the University of Gothenburg and Chalmers University of Technology, Sweden. Patients selection was based on the presence of conductive or mixed hearing loss in patients who are unable to wear a conventional hearing aid because of infection or ear canal problems. Patients had speech discrimination scores of at least 60% for phonetically balanced monosyllables (CID lists) at 40 dB above threshold, and a pure tone bone conduction average of 45 dB hearing loss or better. Patients were evaluated in sound field, preoperatively and postoperatively using warble tones, speech reception threshold, speech discrimination, and synthetic speech identification. The patient's unaided hearing and hearing with a bone-anchored hearing aid were compared with the patient's hearing with a standard bone conduction hearing aid. Signal to noise ratio testing with the synthetic speech identification test demonstrated that the bone-anchored hearing aid was comparable to a standard bone conduction aid. There were no complications in our series. Five patients who reported otorrhea with conventional hearing aids experienced no otorrhea after implantation. Patient satisfaction, as assessed by questionnaire, revealed that all patients preferred the bone-anchored hearing aid to previously worn hearing aids.

Adult↗
PubMed1998

[Embryology of the human carpal bones (triangular cartilage, central carpal bone, morphogenesis of the scaphoid)].

Wax reconstructions according to Born's methods were performed from serial 10-micron sections of the wrists of human embryos (B. Tardif) to study the triangular cartilage and central bone of the carpus. A subsequent morphological study of the adult scaphoid bone was conducted in the light of embryological data. The triangular cartilage was observed in 4 of 38 carpi of embryos with a craniocaudal length of 40 to 69 mm, flatten between the ulna and triquetrum, on the inferior surface of the mesenchymal bud of the triangular ligament. The central bone of the carpus is constant in the embryo, between the inferior surface of the radial chondrification centre, capitatum, trapezium and trapezoid. In one case, the two wrists of the same embryo presented two central nuclei, leading to the distinction of two different formations:--the constant C2 embryonic central bone, trapped between capitatum, trapezoid and trapezium, which participates in the constitution of the scaphoid by fusion with the radial chondrification centre;--the C1 central bone, a rare supernumerary bone in adults, close to the inferolateral angle of the lunatum, on the dorsal surface of the carpus. These embryological data support. Westoll's theory concerning the filiation of the thoracic limb since the fin of crossopterygians, with deviation of the mechanical axis related to the development of weightbearing on the ground. The scaphoid bone must to be assimilated to a cube, but to an irregular tetrahedron, composed of two inverted pyramids joined by their bases. The inferior pyramid, articulating with he trapezium, trapezoid and capitatum, is concerned by morphological variations of the bone, which can present variable configurations between the two extreme morphotypes: the massive type and the strangulated type. The inferior pyramid, constituting the scaphoid, is derived from the central cartilage and presents the same relations. Variations of the volume of this inferior part of the bone are related to the more or less marked regression of this chondrification centre of the embryonic carpus. These variations of the bone can be expressed in terms of a scaphoid index, by calculating the relationship between the greatest dimension and the width of the narrowed portion.

Adult↗
PubMed1997

Assessment of bioactivity for orthopedic coatings in a gap-healing model.

In order to study bone growth conducting capacities of new biomaterials under standardized conditions, a goat model was developed based on a canine model by Soballe. Titanium alloy implants with and without a hydroxyapatite coating were used as positive and negative controls, and these were implanted with a circumferential gap of one millimeter in the spongious bone of the knee condyles of two groups of four goats. These goats were sacrificed at 6 and 25 weeks. A second experiment was done on two groups of four goats with the same type of titanium alloy and hydroxyapatite-coated implants as controls and with Polyactive 55-45 coated titanium alloy implants for testing. These goats were sacrificed at 9 and 25 weeks, respectively. Qualitative and quantitative differences in gap healing were evaluated through light microscopy, and initiation and direction of bone apposition were determined with fluorescence microscopy. Apposition of bone was seen directly on all hydroxyapatite surfaces and on some of the noncoated titanium alloy surfaces. The difference between the percentage of bone growth on the titanium alloy implants and the hydroxyapatite-coated implants appeared to be divergent in time: the bone growth on the noncoated implants declined after 9 weeks in contrast to the steady increase of bone growth on the hydroxyapatite-coated implants towards the 25 week follow-up time (p = 0.02). No significant difference was found between the first and the second experiment: apposition of bone on the implants differed only 6.6% on a scale of 0% to 100%. Only scarce bone growth was seen on the polyactive-coated implants in this model. The newly tested Polyactive 55-45 coating apparently needs initial bone contact for bone-bonding and therefore showed hardly any direct bone formation on its surface. The clear differences in the reaction of bone to the coated and noncoated implants in this goat study and the reproducibility of these reactions of bone to the different controls indicate the sensitivity of the currently used animal model and its suitability for use as a bioactivity assay.

Animals↗
PubMed1994

The bone-anchored hearing aid: principal design and audiometric results.

The principle of the bone-anchored hearing aid (BAHA) is simple: sound vibrations are directly transmitted to the skull bone via a skin-penetrating titanium implant, and then are further transmitted to the cochlea, bypassing the middle ear. The present paper summarized the audiometric results from 122 patients with an average follow-up time of 5.6 years. When herein-suggested indications for treatment with the bone-anchored sound processor HC 300 are followed, the success rate is very high. The improved quality of life reported by the patients is a combination of improved quality of sound (warble tone threshold, speech reception threshold, and discrimination in noise), improved comfort, and relief from middle ear and ear canal disease occasioned by conventional hearing aids.

Audiometry↗