[Spiral CT in arytenoid cartilage dislocation: the optimization of the study parameters with a cadaver phantom and its clinical evaluation]. / Spiral-CT bei Aryknorpel-Dislokation: Optimeirung der Untersuchungsparameter am Leichenphantom und klinische Evaluation.

PURPOSE: To evaluate an optimal scan protocol in a cadaver phantom and its clinical assessment in 40 patients. MATERIALS AND METHODS: In a cadaver larynx phantom helical CT (HiSpeed Advantage; GE, Milwaukee, Wis) was performed with increasing collimation (1-10 mm) and pitch (1.0-3.0). 40 patients with an immobile vocal cord were randomly assigned to undergo CT with a certain protocol. RESULTS: Best resolution was obtained with a collimation of 1 mm and pitch 1. The pitch could be increased up to 2 without losing information. With a collimation of 3 mm and higher, anatomical details were missed. In the patient studies a combination of 1 mm collimation with a pitch of 2.0 showed less motion artifacts than a pitch of 1.0. CONCLUSION: The quality of CT imaging of the arytenoid cartilage depends greatly on the scanning parameters, the compliance of the patients and the mineralisation of the cartilage. For clinical assessment a collimation of 1 mm with a pitch of 2 is recommended. The increase pitch has the advantage of shorter acquisition times and decreased radiation exposure.

[Quality control in pediatric hearing aid fitting]. / Qualitätskontrolle der kindlichen Hörgeräteversorgung.

Specific hearing aid selection and careful fitting are essential for successful rehabilitation of hearing-impaired children. For this reason the different hearing aid types prescribed, the type and frequency of hearing aid insufficiencies reported and the effectiveness and regularity of our follow-ups were studied evaluating 253 followup exams in 39 children (71 ears) suffering of a sensorineural hearing loss, including all degrees, supplied with a behind-the-ear hearing aid. Most of the devices had been prescribed outside our department on an initial trial basis. After critical evaluation, the number of hearing aid types was reduced from 33 to 23 when corresponding devices failed to match well with the degrees and types of hearing losses present. A further decrease in hearing aid types could not be achieved as a consequence of many being already end-prescribed. Insufficiencies (n = 222) were found in 60% of the hearing aid evaluations: 59% involved dynamic hearing aid adjustments requiring better amplification (37%), distortion (18%) and dynamics (4%). Additionally, 16% affected hearing aid function and another 16% form (9%) and material (4%) of the otoplasty and the tube (3%). The last 9% of the deficiencies concerned the potentiometer cap: it hadn't been fitted in about half of the cases and had been lost in the other half despite being needed. Routine followup evaluations of the hearing aids occurred regularly in 76% of the cases with an effectiveness of 73%. Our results confirm the importance and necessity for pedaudiologic qualitative hearing aid controls in children.

[Vestibular function: a prerequisite for normal language development?]. / Die Vestibularisfunktion: Eine Voraussetzung der normalen Sprachentwicklung?

BACKGROUND: First language acquisition depends on intermodal perception, especially auditive, tactile-kinesthetic, and partly visual in addition to sensomotoric integration. The influence of the vestibular function for a physiological language development is still unknown. PATIENT: A case history of a child with bilateral aplasia of all semicircular canals, normacusis in the right ear, and severe sensorineural hearing loss in the left (hearing aid supplied), without mental deficiency, allows us to draw initial conclusions. RESULTS: Logopedic diagnostics revealed only a mild articulation disorder (interdental sigmatism, inconstant gammacism) as a possible consequence of recurrent middle ear effusions since early childhood. Language development diagnostics did not demonstrate any significant norm deviation. CONCLUSIONS: In contrast to the statomotoric disorder, no evidence for a specific language impairment was found. Our report elucidates the importance of a selected diagnostic imaging (spiral CT and MIP MRI) in the phoniatric-ped-audiological field.

[Early detection and hearing aid management of pediatric unilateral hearing loss]. / Früherkennung und Hörgerätversorgung unilateraler kindlicher Schwerhörigkeiten.

BACKGROUND: Unilateral hearing loss in children is frequently an incidental diagnosis, usually late. As in binaural hearing disorders, early detection is extremely important to protect the function of the "remaining ear" and thus ensure acquisition of speech. Prompt initial probatory treatment with a conventional hearing aid is necessary to take advantage of the sensitive phases of development and maturation of the auditory pathways. This allows lateralisation as well as a better discrimination, avoiding cocktail party and non-physiologic head shadow effects. PATIENTS: The study includes 32 children with a conventional hearing aid. The average age of diagnosis was 5.5 years. The children were initially treated with a conventional hearing aid. RESULTS: The etiology remained unknown in the majority of the cases. Twenty-seven of the children were observed over a longer period, averaging 2 years. Hearing aid acceptance was found to be 63% with a measurable hearing improvement in 59% of the patients, even in the presence of severe hearing disorders. In the majority of the cases, the etiology remained unknown. CONCLUSION: More knowledge about risk factors for unilateral hearing losses in children should improve the chances for early detection, making hearing aid supply at a younger age possible. This should happen firstly in a probatory manner and in cases with hearing aid acceptance and a measurable hearing improvement definitely.

[Contact allergy-induced tracheal stenosis caused by vulcanization accelerators in the endotracheal tube?]. / Kontaktallergisch bedingte Trachealstenose durch im Tubus vorhandene Vulkanisationsbeschleuniger?

Tracheal stenoses occur mainly under iatrogenic conditions: they develop specially after long-term intubation, but also after tracheotomy. Etiological-pathogenic relevant factors include the mechanical irritation of mucosa, perichondrium and cartilage in addition to infected tracheal secretions. An allergic cell-mediated reaction in the respiratory tract has been already described. It is seldom recognized. The possibility of such a hyperergic, allergic, delayed reaction (Type IV Coombs-Gell response) with subsequent tracheal stenosis caused by rubber chemicals (accelerators) found in endotracheal tubes is presented in the following case report.

Are implantable hearing devices really necessary?

Indications, advantages and disadvantages of different types of bone-anchored hearing aids and middle ear implants are discussed and compared with conventional hearing devices. The hearing results obtained at the University of Würzburg in 4,195 middle ear surgeries, from January 1988-August 1993, are presented. In those cases where tympanoplasty wasn't able to provide a good hearing result, the additional use of a conventional hearing aid was sufficient. If the gain and maximum output of the implantable hearing aid is improved in the future, the implant may be able to provide intelligible hearing also to patients with a profound sensorineural hearing loss. At this point implantable hearing aids will become really necessary, irreplaceable devices.