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Biomedical subjects

M Tos

Publications and source records attributed to M Tos.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Cochlear implantation in children. The first Danish results].

The aim of this study is to review indication, technique and results of cochlear implant (CI) treatment with Nucleus CI-multi-electrode of the first ten children operated in Denmark (five children with congenital deafness and five with acquired prelingual deafness due to meningitis). In the literature, the importance of early referral and operation at the age 2-3 (4) years for congenital deafness and as soon as possible on suspicion of acquired deafness (meningitis) is stressed. A short survey of our indications, technique and rehabilitation is presented. The results of treatment after 11-44 months' use of CI are that one child has language almost matching age, four use words and short sentences accompanied by support signing, three have sound reaction and say single words without sentence building, but of these two children have only used CI for a very short time and are improving. Two meningitis sequelae cases had cochlear ossification, which made the implantation difficult. Both patients had to be operated, and one of them is not using the processor.

Age Factors↗
PubMed1999

Less radical drilling in surgery for exostoses of the external auditory canal.

OBJECTIVE: To estimate the anatomical and functional long-term result of surgery for ear canal exostosis. METHODS: Case rapport review with extraction of data concerning pre- and postoperative anatomical conditions, symptoms and audiology and a clinical and audiological re-evaluation. In the 20-year-period from 1 January 1976 to 1 January 1996, 26 patients were operated on primarily for ear canal exostosis. 19 patients with in total 24 ears were re-evaluated. Control-period 7.2 years. Pre-operatively were found occluding ear-canal exostosis in all patients as well as hearing loss, otitis externa and pain. RESULTS: At the re-evaluation all patient were completely free of their symptoms. 19 out of 24 ears still had some remnants of exostosis, but the ear canal was covered with completely normal skin and had normal migration properties. No signs of re-growth were found in this material. Postoperatively one patient had a sensorineural hearing loss of 85 dB at 6 kHz, one had a dehiscence of the temporomandibular joint and one patient had an anterior ear drum perforation. CONCLUSION: To avoid the complications a less radical drilling of exostoses is proposed, in particular along the superior wall and near the short process of the malleus handle and along the anterior tympanomeatal angle. Removal of the bone from the posterior, inferior and anterior walls with preservation of the canal skin, creates enough lumen providing permanent cure.

Adolescent↗
PubMed1999

Isolated congenital stapes suprastructure fixation.

Isolated congenital anomalies of the ossicles are rare. The majority of cases of congenital conductive hearing loss secondary to middle-ear anomalies have other associated defects, such as atresia, microtia and craniofacial deformities. We present a rare case of isolated congenital stapes suprastructure fixation, where a monocrural stapes with a mobile footplate was attached to the promontory by bony synostosis. There was no stapedius muscle nor pyramidal process. The incus and malleus were of normal configuration. Mobilization of the stapes from the promontory resulted in improvement in hearing. We believe this is the first reported case of such an abnormality. A review of the world literature of isolated stapes suprastructure ankylosis and the classifications of minor congenital anomalies are discussed.

Adult↗
PubMed1999

Management of intrameatal vestibular schwannoma.

The growth of purely intrameatal vestibular schwannoma (VS) was investigated, in the period 1973-96 in a series of 40 patients with 40 unilateral VS. In the present study, the material was analysed and updated. By the end of the observation period (mean 3.6 years), 27 tumours (67.5%) revealed growth and 13 tumours (32%) had no measurable growth. Four growth patterns were observed: (A) 15 tumours (37.5%) exhibited constant growth; (B) 13 tumours (32.5%) had no measurable growth; (C) 8 tumours (20%) revealed growth subsequent to a no-growth period; and (D) 4 tumours (10%) showed different growth patterns during the observation period. The annual diameter growth rate ranged between 00 mm/year and 6.5 mm/year and the mean diameter growth per year was 3.2 mm. The findings of the present study, especially those for group B (the non-growing tumours) and C (tumour growth subsequent to a silent period) bring into question the reliability of the results achieved by radiosurgery, as without any intervention it may be that no tumour growth occurs.

Adolescent↗
PubMed1999

Topical budesonide treatment reduces endothelial expression of intercellular adhesion molecules (vascular cell adhesion molecule-1 and P-selectin) and eosinophil infiltration in nasal polyps.

Infiltration of eosinophil granulocytes and endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) and P-selectin was investigated in biopsies of polyps and inferior turbinates from 16 patients with nasal polyps, by the use of immunohistochemical staining and stereological quantification before, during and after topical treatment with budesonide (Rhinocort Turbuhaler). Before glucocorticoid treatment a higher density of eosinophil profiles (p < 0.005), making up a larger proportion of the total cellular infiltrate (p < 0.0005), was found in the polyps compared with the inferior turbinates. Endothelial VCAM-1 expression was higher in polyps than in inferior turbinates (p < 0.005), in contrast with the expression of P-selectin, which was more frequently expressed in the inferior turbinates (p < 0.05). Topical glucocorticoid treatment reduced the density of eosinophil profiles (p < 0.05) and the endothelial expression of VCAM-1 (p < 0.007) and P-selectin (p < 0.02) in polyps. Eosinophil counts and VCAM-1 expression returned to pre-treatment levels 8 weeks after discontinuation of budesonide treatment. The observed reduction in endothelial expression of cellular adhesion molecules may interfere with cellular recruitment in nasal polyps and thus contribute to the known anti-inflammatory effect of glucocorticoid in nasal polyposis.

Administration, Topical↗
PubMed1999

Bone modeling dynamics in acute otitis media.

OBJECTIVE: A number of middle ear diseases are associated with pathologic bone modeling, either formative or resorptive. As such, the pathogenesis of a sclerotic mastoid has been controversial for decades. Experimental studies on acute middle ear infection have shown varying degrees of both osteoresorption and osteoneogenesis. This study presents data on the dynamics of bone modeling in a rat model of acute pneumococcal otitis media, studied longitudinally from day 1 through 6 months after inoculation. RESULTS: Qualitative, as well as quantitative histopathology revealed initial osteoresorption, followed by increasing apposition of new bone in the middle ear cavity, initiated at the outer periosteum. Measured bone thickness in four anatomically distinct locations peaked 3 months after inoculation, followed by some degree of normalization. However, bone thickness was still massively increased 6 months after the acute incident. Except in perilymphatic spaces of the otic capsule, resorptive and formative activity were found in all bone tissue structures surrounding the middle ear cavity, including the bony external auditory canal and the ossicles. CONCLUSION: These findings may support the existence of a perilymphatic barrier of specialized bone and suggest that even a single episode of acute infection may alter properties of ossicular chain conduction. The authors conclude that acute otitis media is accompanied by massive and progressing net osteoneogenesis, already evident at 3 days and peaking 3 months after inoculation, followed by some degree of normalization. This is conceivably in support of the environmental theory of mastoid pneumatization, claiming inflammatory disease as the cause of a sclerotic mastoid.

Acute Disease↗
PubMed1999

Incidence of vestibular schwannomas.

OBJECTIVE: To determine the incidence of vestibular schwannoma (VS) in Denmark in a period of 191/2 years. STUDY DESIGN: Retrospective review of prospective registered data on all patients with VS operated on by the translabyrinthine, lateral suboccipital, or middle cranial fossa approach, as well as patients who were allocated to the "wait-and-scan" group. METHODS: Charts were reviewed and tabulated for age, extrameatal tumor extension, and date of diagnosis. The available data were divided into three periods: June 1976 to June 1983, July 1983 to June 1990, and July 1990 to December 1995. RESULTS: The number of newly diagnosed tumors in the first period was 278, corresponding to an incidence of 7.8 tumors/million population per year; in the second period 337, corresponding to an incidence of 9.4 tumors/million population per year; and in the third period 355, corresponding to an incidence of 12.4 tumors/million population per year. A significant increase in incidence of the newly diagnosed intracanalicular tumors in the second and third periods was observed. CONCLUSION: The increase in incidence of VS can probably be explained by the awareness among otolaryngologists of the diagnosis of VS and better access to computed tomography and magnetic resonance imaging scans. The observed increase in the diagnosis of the small and intrameatal tumor creates a clinical dilemma, whether to operate on tumors in this early stage or to allocate patients to the wait-and-scan group. This problem will still be relevant in the upcoming years, since the incidence of intrameatal and small VS is expected to increase.

Denmark↗
PubMed1999

Penicillin reduces new bone formation in acute otitis media.

OBJECTIVE: Previous studies have shown that acute otitis media alters modeling dynamics in bone tissue structures surrounding the middle ear cavity. Initial resorption is followed by formative activity, which is seen as massive osteoneogenesis. However, neither resorptive nor formative activity occurs in the otic capsule, supporting the theory on existence of a perilymphatic barrier of specialized bone. STUDY DESIGN: To investigate the effect of penicillin administration on the pathological bone modeling in acute otitis media, we employed a rat model of acute pneumococcal otitis media. METHODS: Five rats were sacrificed on postinoculation days 4, 8, 16, 90, and 180, preceded by oral administration of penicillin V 100 mg/kg per day, initiated on day 2 and lasting 5 (2) days. Using a light microscope, bone histomorphology was registered and the thickness measured in four well-defined localities, followed by comparison with a previous study of untreated animals. RESULTS: Measured bone thickness was unaffected by treatment on day 4, but significantly reduced in two localities on day 8 and in all localities on following days of sacrifice. Bone cytomorphology and histomorphology were otherwise unaffected by penicillin administration. CONCLUSION: Penicillin reduces new bone formation in acute otitis media, leaving other features of histomorphology unchanged.

Acute Disease↗
PubMed1998

[Therapeutic results of surgery for exostoses of the ear canal].

A relatively high complication rate in surgery for ear canal exostoses is reported in the literature. It was found of interest to review our long-term results of surgery in ear-canal exostosis, using case-report review and clinical and audiological re-evaluation. Nineteen of 26 patients, 24 ears, operated in the 20-year period 1976-1996 were re-evaluated, mean time from surgery 7.3 years. All patients were found preoperatively to have occluding ear canal exostoses with a variety of related symptoms, all were in most cases operated via the trans-canal approach. At the re-evaluation all patients were completely free of symptoms, even though exostosis remnants were found in 19 of 24 operated ears. The complication rate was 12.5%. In conclusion, in order to avoid the complications found in this material as well as in other reports a less radical removal of exostoses is proposed.

Adolescent↗
PubMed1998

[Benign neoplasms in the parotid gland in the county of Copenhagen 1986-1995].

In a ten year period from 1986-95 433 patients were submitted to operation due to benign tumours in the parotid gland in Copenhagen County. In this study we made a retrospective analysis of the surgical outcome. The incidence was calculated to be 6.8 benign tumours in the parotid gland per 100,000 persons per year. The histological distribution showed a frequency of 54% pleomorphic adenomas, 28% adenolymphomas and 18% other tumours. In the observation period there was a 3% recurrence rate in our material, most frequently the pleomorphic adenoma. The risk of permanent damage to the facial nerve was 1% for severe injury and 3% for affection of the ramus marginalis. Frey's syndrome was present in 50% of the patients, moreover the syndrome was observed many years after surgery. The frequency rate reached its highest level about five years postoperatively.

Adenolymphoma↗
PubMed1998

Clinical experience with vestibular schwannomas: epidemiology, symptomatology, diagnosis, and surgical results.

The Danish model for vestibular schwannoma (VS) surgery has been influenced by some historical otological events, taking its origin in the fact that the first attempt to remove CPA tumors was performed by an otologist in 1916. In approximately 50 years VS surgery was performed by neurosurgeons in a decentralized model. Highly specialized neuro- and otosurgeons have been included in our team since the early beginning of the centralized Danish model of VS surgery in 1976. Our surgical practice has always been performed on the basis of known and proven knowledge, but we spared no effort to search for innovative procedures. The present paper reflects the experience we have gained in two decades of VS surgery. Our studies on the incidence, symptomatology, diagnosis, expectancy and surgical results are presented.

Craniotomy↗
PubMed1998

Surgery for acquired cholesteatoma in children: long-term results and recurrence of cholesteatoma.

The aim of the study was to evaluate the long-term results after surgery for acquired cholesteatoma in children and to contribute to the search for predictors of recurrence. During a 15-year period, 114 children underwent surgery. The patients were re-evaluated with a median observation time of 5.8 years. At the last re-evaluation 85 per cent of the ears were dry with an intact drum. Recurrence of cholesteatoma developed in 27 ears. The cumulated total recurrence rate was 24 per cent using the incidence rate calculation, applying Kaplan-Meier survival analysis the corresponding recurrence was 33 per cent. Recurrent disease occurred significantly more frequently in children younger than eight years, with a negative pre-operative Valsalva, with ossicular resorption and with large cholesteatomas. In conclusion, young children with poor Eustachian tube function and a large cholesteatoma with erosion of the ossicular chain, are at special risk of recurrence and should be observed for several years after surgery.

Adolescent↗
PubMed1998

Changes in mucosal goblet cell density in acute otitis media caused by non-typeable Haemophilus influenzae.

The correlation between secretory otitis media and increased goblet cell density in the middle ear mucosa is well established. Previous studies have shown that a single episode of acute otitis media caused by Streptococcus pneumoniae is followed by increased goblet cell density for a period of at least 6 months, conceivably predisposing a subsequent development of secretory otitis media. In this study, 25 rat middle ears were inoculated with non-typeable Haemophilus influenzae in order to determine the effect on mucosal goblet cell density. Five rats were killed on days 4, 8, 16, 60 and 180 postinoculation, followed by dissection, staining and whole-mount embedding of the middle ear mucosae. The goblet cell density was determined in 24 well-defined localities. Compared with 25 normal middle ears, the goblet cell density was significantly increased in almost all localities, at all days on which the animals were killed. Thus, increased goblet cell density and enlargement of mucosal areas containing goblet cells persisted 6 months after the acute incident. The induced increase of goblet cell density was higher than the increase following inoculation of S. pneumoniae. We conclude that acute otitis media caused by non-typeable H. influenzae is followed by a longstanding increase in mucosal secretory capacity, likely to predispose a subsequent development of secretory otitis media.

Animals↗
PubMed1998

The non-specific effect of endolymphatic sac surgery in treatment of Meniere's disease: a prospective, randomized controlled study comparing "classic" endolymphatic sac surgery with the insertion of a ventilating tube in the tympanic membrane.

A prospective, randomized study was carried out comparing the effect of two surgical modalities in the treatment of patients with Meniere's disease: insertion of an endolymphatic sac shunt and insertion of a ventilating tube in the tympanic membrane. A total of 29 patients, 12 males and 17 females, age 27-71 years, were operated on in two ear, nose and throat (ENT) departments. Of these patients, 15 had an endolymphatic shunt inserted and 14 had a ventilating tube inserted in the tympanic membrane. Postoperative follow-up was carried out in the department in which the patients had not been operated. The severity of the disease was scored pre- and postoperatively, and the results evaluated under the guidelines of the Committee on Hearing and Equilibrium (1995) for the diagnosis and evaluation of therapy in Meniere's disease. The patients in both groups had a statistically significant reduction in dizzy spells, measured 6 and 12 months postoperatively, and there was no difference between the groups. The pathophysiological explanation for the reduction in dizzy spells in each of the treatment modalities is debatable and the effect is non-specific. The patients' hearing and tinnitus were statistically unaffected by the treatment in both groups, though 2 patients in the shunt group developed severe hearing loss (anacusis/70 dB).

Adult↗
PubMed1998

Acoustic neuroma/vestibular schwannoma growth: past, present and future.

The growth of vestibular schwannoma (VS) was investigated in a series of 123 patients with 127 tumors in the period 1973 1993. The material was reanalysed and updated 3 years later in 1996. By termination of the first observation period (mean 3.4 years), 94 tumors (74%) exhibited measurable growth, 23 tumors (18%) no measurable growth and 10 tumors (8%) negative growth. By the end of the extended observation period (mean 3.8 years), tumor growth was observed in 104 tumors (82%), no tumor growth in 15 tumors (12%) and negative growth in eight tumors (6%). Several growth patterns were noticed: however, these were not static as the growth patterns of the tumors changed during the extended observation period. Accordingly, the expected growth figures by the end of this century (mean observation period approximately 4 years) will probably be: growth in 111 tumors (87%), no growth in 10 tumors (8%) and negative growth in six tumors (5%). The results indicate that neither the present study nor the previously published studies on tumor growth reflect the natural history of VS, but they only provide information on tumor growth, growth rates and growth patterns during a given observation period.

Adolescent↗
PubMed1998

Expression of intercellular adhesion molecule-1 on the vascular endothelium in nasal polyps before, during and after topical glucocorticoid treatment.

Nasal polyposis is a result of a chronic inflammatory disorder in the upper airways. In vitro studies have revealed that extravasation of leucocytes requires interactions between several sets of adhesion molecules expressed on the circulating leucocytes and the vascular endothelium. Therefore, the endothelial expression of intercellular adhesion molecule-1 (ICAM-1) in biopsies from polyps and inferior turbinates was investigated by the use of immunohistochemical staining. Biopsies were obtained from 11 patients suffering from nasal polyposis before, during and after treatment with 100 microg budesonide (Rhinocort Turbuhaler) in each nostril twice daily. Before, during and after treatment, ICAM-1 was expressed in the majority of vessels in polyps and mucosa of inferior turbinates. The intensity of endothelial ICAM-1 expression in polyps was significantly reduced during topical glucocorticoid treatment compared with the pretreatment and posttreatment levels (p < 0.005). In biopsies from the inferior turbinates, the intensity of the endothelial ICAM-1 expression was lower during treatment than after discontinuation of medical treatment (p < 0.005). In conclusion, topical budesonide treatment seems to downregulate ICAM-1 expression on the vascular endothelium in nasal polyps. Such an effect may interfere with leucocyte extravasation and partially account for the anti-inflammatory effect of local glucocorticoid treatment in human nasal polyposis.

Administration, Topical↗