Biomedical subjects
Publications and source records attributed to R Laszig.
The regulations for the testing and prevention of noise-induced hearing loss in German industry since 1974 are summarized. Current testing involves both speech and impedance audiometry. While initials studies will be directed through occupational medicine, definitive managements will be provided by otolaryngologists involved in the prevention program.
The Rosai-Dorfman syndrome is a benign disease, one of its commonest affected sites being the cervical lymph nodes. This disease should be considered in the differential diagnosis of a cervical lymphadenopathy. The syndrome often begins with a chronic rhinitis, and is accompanied by sinusitis, tonsillitis or pharyngitis; blood tests indicate chronic infection. The pathogenesis of the disease is still unknown but may include infection or an abnormal autoimmune reaction. The diagnosis is established by the findings of characteristic histiocytes with haemophagocytosis. We report a female patient with persistent cervical lymph node swelling resistant to treatment. The cause was proved by histology to be a Rosai-Dorfman syndrome.
Out of total of 164 patients with chronic sinusitis undergoing intranasal microsurgery, 94 patients were submitted to a detailed analysis one year later. The patients were divided into groups of polypoid and hyperplastic sinusitis, depending on the morphological appearances and the histology of the tissue removed. Patients with polyps showed a significantly higher rate of recurrent (47%) than patients with hyperplastic sinusitis (8.6%). Allergy or bronchial asthma did not influence significantly the rate of recurrence in patients with nasal polyposis, whereas patients with a hyperplastic sinusitis showed a higher recurrence rate if they were atopic as well. However, even patients with polypoid sinusitis gained marked long-term relief of nasal obstruction and other symptoms.
Due to their surgical inaccessibility and resistance to radiotherapy, clivus chordomas represent a formidable therapeutic challenge. The transoral approach to chordomas of the clivus has been usually restricted to relatively small or midsized neoplasms, located at the lower end of the clivus or at the anterior clival-cervical junction. In this report the transoral transpalatal transclival removal of a giant recurrent chordoma occupying the whole length of the clivus with considerable premesencephalic extension and brain stem compression is described. Regression of preoperative symptoms without additional postoperative morbidity could be achieved by radical transoral tumour extirpation documented by magnetic resonance imaging.
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Between August 1984 and August 1990, 166 patients received a 22-channel cochlear implant (Nucleus) in the ENT clinic in Hannover. Some of these patients who were able to understand speech nevertheless complained of inadequate perception. To study this further a phantom skull with a cochlear implant was examined by CT and by conventional tomography of the petrous bone in various image planes. The method of choice for evaluating the position and appearance of the cochlear implant proved to be conventional tomography of the petrous bone in the frontal transorbital plane. In 7/23 patients examined it was possible to demonstrate dislocation of the electrodes; this is evidently responsible for the faulty perception.
The surgical complications for the first 153 multiple-channel cochlear implant operations carried out at the Medizinische Hochschule in Hannover and the first 100 operations at the University of Melbourne Clinic, The Royal Victorian Eye and Ear Hospital, are presented. In the Hannover experience the major complications were wound breakdown, wound infection, electrode tie erosion through the external auditory canal, electrode slippage, a persistent increase in tinnitus, and facial nerve stimulation. The incidence of wound breakdown requiring removal of the package was 0.6% in Hannover and 1.0% in Melbourne. The complications for the operation at both clinics were at acceptable levels. It was considered that wound breakdown requiring implant removal could be kept to a minimum by making a generous incision and suturing the flap without tension.
Electrically elicited stapedius reflexes were examined in 25 deaf patients who had received a 22-channel Clark/NUCLEUS cochlear implant. Using an apical, a medial and a basal electrode pair, different stimulation positions within the cochlea and different stimulation modes were examined. For threshold determination, 10 reflexes were averaged with reflexes recorded on the nonoperated side. Reflexes were elicited in 19 of the 25 patients (76%); a saturation of reflex amplitude could be recorded in 14 (56%) subjects. In two additional cases, a reflex could be obtained by increasing the bipolar stimulation width (changing the stimulation mode). In comparison with different stimulation positions within the cochlea, the stimulation of apical electrodes produced more distinctive reflexes and required lower current levels. An increase in the bipolar stimulation width also decreased the intensity required for stapedius reflex threshold. Our data suggest that stapedius reflex evaluation may be a useful tool for speech processor fitting.
Dose-dependent reduction of auditory function mainly in the high frequency range has been described as a common adverse side effect of cis-platinum. Here we report on a 4-year-old girl with osteosarcoma of the right distal femur who developed acute bilateral deafness 3 days after a single infusion of high-dose cis-platinum (150 mg/m2) during preoperative chemotherapy. Sudden disabling ototoxicity should be considered when administering high-dose cis-platinum to young children.
The Melbourne/Cochlear multiple-electrode extracochlear implant is designed for deaf patients who are unsuited to multiple-electrode intracochlear implantation. The implant consists of a receiver-stimulator package connected via a lead wire assembly to six individual stimulating electrodes. There is a choice of two alternative surgical procedures, both of which are via a combined middle ear approach using anterior and posterior tympanotomies. Four active electrodes shaped into compressible platinum-iridium soft-balls are fed through the mastoid cavity and across the facial recess, and placed into cavities that are made over the cochlear turns that project to the medial wall of the middle ear. One hard-ball active electrode is placed into the round window niche. One hard-ball reference electrode is placed into the hypotympanum. An additional electrode wrapped around the lead wire assembly can be used as an alternative reference electrode. A specially designed insertion needle facilitates the placement and the fixation of the soft-ball electrodes.
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Tumors of the head and neck are mainly squamous cell carcinomas of varying differentiation. If the tumor is advanced (T3-T4) or distant metastases are present, the tumor is often to be regarded as inoperable. If cure is unlikely or substantial functional impairment is to be expected, surgery may no longer seem reasonable, even for tumors limited to one side. Since either radiotherapy or chemotherapy alone or in combination are often disappointing or have considerable side-effects, it seems reasonable to try to inhibit malignant cell growth by administering a cytostatic agent by intra-arterial "superselective" chemotherapy using an implantable catheter. The method is simple, and the patients may also receive combined radiotherapy if necessary. Furthermore, ambulant treatment is possible, with a substantially reduced risk of infection. This is an advantage compared with other catheter techniques, particularly in view of the restricted expectation of life of patients with advanced tumor. The disadvantage of "A-port implantation" is that chemotherapy can only start after complete wound healing.
Meningiomas are common intracranial neoplasms, making up 19.5 per cent of all intracranial tumours. Meningiomas occurring outside the central nervous system are uncommon. In this report should be presented an extradural meningioma of the left nasal cavity, which was diagnosticated in an 78-year-old female. These slowly growing non-infiltrating tumours have no characteristical clinical symptoms, they cause nasal obstruction and sinusitis. The origin of these tumours is uncertain. Obviously intranasal meningiomas take their origin from the arachnoideal meningocytes which accompany the olfactory filaments through the lamina cribrosa to the extradural site.
We report a 13-year-old boy with peripheral dysostosis, nasal hypoplasia, brachydactyly and a tracheal stenosis of unknown origin. Acrodysostosis is usually caused by an autosomal gene, but in this case it was probably due to a new mutation. The frequently described mental retardation is not essential feature. Ectopic calcification has not been previously reported.
The use of electrical stimulation for the treatment of tinnitus was evaluated on 38 cochlear implant patients suffering from chronic tinnitus. In answer to a questionnaire 29 (76%) of the subjects reported a reduction of the tinnitus while using their speech processor; 15 even noted complete suppression. Sixteen patients used a processor delivering subthreshold current for 2 weeks. A placebo trial followed. Reduction of tinnitus was found in only 3 (19%) of the patients; however, 13 (81%) mentioned a substantial decrease of tinnitus when using their own device with above-threshold stimulation. The fact that tinnitus was also reduced on the contralateral side suggests that the acoustic masking effect must be the main determining factor rather than electrical stimulation. Therefore, the best therapy for the deaf seems to be the improvement of their hearing ability.
The most common clinical symptom of toxoplasmosis in adults is a cervicofacial lymphadenopathy. The cat is very important in the epidemiology of toxoplasmosis, but contact with cat excreta is most uncommon. The cause of oral transmission in adults is more likely to be eating undercooked contaminated meat containing tissue cysts, particularly raw pork. Toxoplasmosis as a cause of lymphadenopathy is an unusual, and normally postoperative, finding after parotidectomy for a "tumour". In the last 8 years we have seen ten patients with an acute toxoplasmosis infection. We report two patients showing clinical signs of a parotid gland tumour in whom we demonstrated an intraglandular toxoplasmosis lymphadenopathy before operation. We treated these patients successfully using pyrimethamine and sulphonamide, so that surgery was unnecessary.
The electrocochleographic findings of 3 unusual cases from about 350 performed on patients with various hearing loss are presented; they demonstrate the value of electrocochleography as a clinical tool in otological investigation. The first case was an electrocochleographically detected acute impairment of the first neuron, the second a hereditary hearing loss with endolymphatic hydrops, and the last shows the effect of an endolymphatic shunt on a hydropic hearing loss.
Psychophysical data such as threshold and comfort levels indicate an extensive preservation of auditory nerve fibers. Changes of these data can point to increasing damage of nerve fibres due to long-term electrical stimulation or to obliteration of the cochlea when an intracochlear system is used. Unfavourable levels indicate negative influence on speech comprehension. The psychophysical data and the speech comprehension of 10 patients fitted with a Clark/NUCLEUS cochlear implant in the last 2 years have been analysed. During this period of time the threshold and comfort levels remained almost stable, whereas speech comprehension is still increasing, though to a lesser extent, after 2 years with the implant. These results indicate that the patients suffer neither an increasing destruction of auditory nerve fibres nor severe intracochlear changes.