PubMed Health⌕ Search

Biomedical subjects

K Begall

Publications and source records attributed to K Begall.

At least 19 recordsLinked to original sources
PubMed2007

[Recurrent facial paresis with facial neurinoma].

PATIENT: A clinical case of a 49-year-old man is described who presented with a right facial paresis for 4 weeks. The patient had undergone a decompression of facial nerve and a radical mastoidectomy elsewhere in 1998 because of a facial paresis and acute mastoiditis. In the following years a complete right facial paresis occurred several times improving with prednisolone. In addition to topognostic examinations a high resolution computed tomography of the temporal bone was made. CT showed a mass in the right tympanic cavity with close contact to the ossicular chain. Diagnostic tympanotomy disclosed a tumor of the tympanic segment of the facial nerve. Pathological examination indicated a diagnosis of neurinoma with an Antoni B architecture. In a second operation the tumor was resected totally and a facial nerve reconstruction was performed by a greater auricular nerve interposition graft. Seven month postoperative beginning nerve reinnervation was seen proceeding continually until the control examination after 1 1/2 year. DISCUSSION: Facial neurinoma are a rare course of facial paresis. There are no specific symptoms. That's why the diagnosis is difficult. But it is necessary to think of with differential diagnosis of facial paresis.

Cranial Nerve Neoplasms↗
PubMed2004

[Otosialorrhoea - diagnostics and therapy of a salivary fistula of the external auditory canal].

PATIENT: We report the case of a 49 year old female patient who suffered from frequent secretion of the left external canal of the ear after the treatment of a chronic mycotic otitis externa. The secretion was seen in connection with food intake. An operative revision in another hospital remained without success. The diagnostics covered the biochemical verification of saliva-amylase in the secretion, but also a high resolution MRI of the parotid gland. By this diagnostics it was easy to locate the salivary fistula during the operation. DISCUSSION: Salivary fistulas of the parotid gland to the external ear-canal are very rare. These fistulas develop after injury of the parenchyma or the gland ductus and also after surgery of the head- and neck-region. A otosialorrhoea rarely originates from a chronic inflammatory of the ear canal. These fistulas are assigned to the fissures of Santorini and the foramen of Huschke. The therapy of salivary fistulas to the external ear canal reaches from clossure of the fistula to total parotidectomy. But also a medicamental suppression of salivation, irradiation and a tympanic neurectomy are discussed in the literature.

Chronic Disease↗
PubMed2002

[Infantile myofibromatosis of the tongue - a case-report].

PATIENT: We report a case of infantile myofibromatosis of the tongue in a 5 month old female child. The parents reported discovering the tumor in the musculature of the tongue and the tumor had largely grown in size in the space of 4 weeks. The child's health was not impaired at any time. After a specimen was removed for a histological examination, an infantile myofibromatosis was diagnosed. DISCUSSION: The occurrence of these tumors in neonates and young children in the oral cavity and in particular in the tongue is rarely reported. Development of the benign tumor disease depends on the form of the tumor, which can be distinguished between a solitaire, a multiloculaire and a generalized form. In contrast to the other two forms, cases of generalized infantile myofibromatosis involve the visceral organs and have a poor prognosis with a mortality rate of 75 %. Spontaneous remission is often reported in the solitaire and multiloculaire varieties of infantile myofibromatosis.

Biopsy↗
PubMed2000

[Reconstruction of the ossicular chain with titanium implants. Results of a multicenter study].

BACKGROUND: For decades, oto-surgeons have been trying to find suitable alloplastic materials for replacing ossicles in the case of morphological and functional disorders in the middle ear. The focus of attention has been on tissue tolerance and functionality. PATIENTS: A retrospective analysis of the implantation of titanium prostheses is presented (Type "Duesseldorf", Heinz Kurz GmbH, Dusslingen, Germany) in 528 patients operated in 14 ENT hospitals. The hospitals involved are ENT hospitals with different fields of specialization presenting a representative cross-section of surgical ENT treatment. Evaluated were healing results, hearing gain and surgical handling of the implants. RESULTS: Despite pathological middle ear conditions, the tissue-implant healing rate was very high. In 4.4% of the patients the implants were rejected. In the case of partial ossicular reconstruction, an average hearing gain between 10 and 20 dB was achieved. Total reconstruction of the ossicular chain showed even better audiological results (15 to 20 dB on average). CONCLUSION: Due to the good morphological and functional results achieved, titanium implants have proven their worth for middle ear micro-surgery. Their advantages are their light weight and delicate structure, facilitating very good micro-surgical handling. It is advisable to place a thin layer of cartilage between the prosthesis headplate and the tympanic membrane. In this manner, the number of material extrusions can be safely reduced, however, extrusions cannot completely be avoided.

Adolescent↗
PubMed2000

[Bilateral genuine cholesteatoma--a case report].

We report on a patient who has been in otorhinolaryngological treatment for more than 24 years owing to recurrent infra-auricular fistulation. Early hospital admissions were due to suspected abscess-forming parotitis or lymphadenitis. As far as could be discerned, no sonographical or radiological diagnostics were conducted. Complications in the sense of meningitis or labyrinthitis were not reported. In the case of the aforementioned patient a bilateral anomaly in the area of the external auditory canal went hand in hand with the development of a bilateral genuine cholesteatoma. The auriculae were configurated normally. Corrective radical surgery was conducted on both sides, first the left, then the right side. What seems remarkable in this context is the fact that despite a over two decades old cholesteatoma there was no erosion of the osseous boundaries of the eardrum towards the labyrinth and cochlea and the osseous cover of the canalis facialis. The patient was diagnosed with a high degree loss of hearing. It was not possible to derive reproductive acoustic potentials intraoperatively, which pointed to deafness. Whether this deafness was congenital or developed in the course of time based on a growing sensory hearing loss could not be ascertained.

Cholesteatoma, Middle Ear↗
PubMed1998

[Practice surgery on the artificial temporal bone. Development of temporal bone facsimiles with stereolithography].

Learning microsurgery of the middle ear requires preparations of temporal bones. Ethical and moral restrictions in obtaining specimens make training and research with temporal bone preparations increasingly more difficult. Due to the complex structure of the temporal bone with its communicating cavities, the manufacture of facsimiles up to now has been impossible. Rapid prototyping techniques must be able to produce identical objects from an original one. By using CT scans of temporal bones from anatomic preparations and patients we have been able to reconstruct 3D pictures on a CAD workstation. We are now able to incorporate data in a stereolithographic system to create an anatomic facsimile of the temporal bone. It is possible to produce a considerable number of these facsimiles from the same real object. With this method we can produce models of human structure for medical teaching, training and research. Our artificial preparations of temporal bones correspond to both the material characteristics and anatomic details of human structures, allowing various surgical exercises to be carried out.

Computer Simulation↗
PubMed1998

[Histological studies of tympanic membrane rim defects in chronic otitis media mesotympanalis].

In the present study we investigated resected tympanic membranes taken during tympanoplasty. Tissue from 111 patients with chronic otitis media was analyzed after being embedded in paraffin and stained with hematoxylin and eosin. In 67 patients (60%) the tympanic membrane epidermis did not extend beyond the margin of the perforation rim, so that no epithelial migration was observed on the inner side of the tympanic membrane. In 27 specimens (24%) we found an epithelial migration on the inner side of the tympanic membrane, but this did not extend to the margins of the excised tissue. In 17 tissue specimens (16%) epithelial migration extended to the margins of the resected tissue. Clinically, these patients were found to have non-functioning Eustachian tubes. The size of the tympanic membrane perforation was not found to impact on epithelial migration. However, there was a correlation between the extent of the epithelial migration seen in the specimens and the occurrence of a permanent tympanic membrane perforation after tympanoplasty. Of 17 patients with these findings, 4 (23%) had consistent reperforations. The tympanic membrane rims of these patients were completely covered with squamous epithelium. Patients with no or only little epithelial migration to the inner side of the tympanic membrane were found to have a significantly lower postoperative rate of recurrent infection and drum reperforation.

Adolescent↗
PubMed1998

[An optimal electrode position for recording auditory evoked brain stem potentials within the scope of pediatric audiology].

BACKGROUND: Estimation of hearing threshold in children is based on reliable identification of a response to a stimulus in the near-threshold range. It is well known that only wave V can be detected in brainstem potentials evoked by near-threshold stimuli. So the question arises as to whether or not a noncephalic reference electrode compared to the common lateral postition of the reference electrode on the ipsilateral mastoid produces a more stable wave V of increased amplitude. METHOD: Thirty-three normal hearing children in three age groups (< 6 years, 6-10 years, > 10 years) were investigated. For a near-threshold stimulation with 100-microsecond-clicks (10, 20, 30 dB nHL), bioactivity was simultaneously recorded with the reference electrode in four different locations (ipsilateral mastoid, contralateral mastoid, ipsilateral earlobe, and noncephalic electrode). RESULTS: The noncephalic reference produced the highest absolute and scaled amplitudes. This finding was statistically significant. For all investigated intensities, recording with the noncephalic reference electrode yielded the highest number of reliable detectable potentials. Evaluation of the residual noise in the four recording locations revealed a significantly increased noise level for the noncephalic electrode at the nape of the neck. CONCLUSIONS: Even if the residual noise is increased, the use of noncephalic reference results in a more reliable detection of wave V compared to the conventional locations of the reference electrode.

Adult↗
PubMed1997

[Correlation between ear canal resonance and tympanic membrane impedance in relation to age and body mass and postmortem changes].

The human temporal bone preparation is an acknowledged model for research of the physical processes affecting the outer ear canal and eardrum. Changes affecting the oscillation and resonance behavior of the tympanic membrane and ear canal between death and temporal bone preparation presently exist in only a few studies. Since the influence of age and physique, as well as the width of ear canal on the ear canal resonance may be important, we prepared two separate studies to analyze these questions. The goal of our first test series involved children and was devised to determine if changes in the outer auditory canal resonances differed according to age. In so doing, canal resonance was recorded with a real ear measurement system. Further, we recorded middle ear pressure, impedance of the tympanic membrane, ear canal volume, height, weight and surface of the body, head and ear size. We found a significant decrease in the resonance frequency of the outer ear which was age-dependent and was 2.75 kHz in the 7-year-old child. In a separate study we wanted to know if results found in the postmortem temporal bone reflected in vivo relationships. A tympanometer and real ear measurement system was used to test the resonance behavior of the auditory canal as well as the vibration of the eardrum in dependence on temperature and the time after death for 9 h. We then proved the absence of significant changes in the auditory canal and eardrum oscillation in this time period before possible postmortem changes occurred. Our findings show that the method of bone preservation after its preparation is decisive for the validity of measurements in the isolated human temporal bone.

Acoustic Impedance Tests↗
PubMed1997

[Methodological aspects of observations of rapid tympanic membrane movements due to changes in static pressure (Valsalva maneuver) using digital high speech video recordings].

BACKGROUND: CCD-high speed camera systems are used to record high frequency videoclips. Introducing this technology in the analysis of eardrum motions, fast motions of the eardrum can be taped using an endoscope. METHODS: Records of the eardrum were made under specific static pressure conditions during the Valsalva maneuver. Initial experience with the help of a Kodak image (I 3) Ektapro 1000 Motion Analyzer allowed only conventional video signal processing and storage. A new data interface makes it possible to save and process the complete videoclip digitally. RESULTS: Using an image processing workstation and special mathematical algorithms, three-dimensional computer animations of rapid eardrum motions on static pressure can be performed. The present study describes different animations of fast motion eardrum movements. CONCLUSIONS: Digital high-speed video imaging is a suitable method to describe rapid eardrum motions on static pressure (Valsalva maneuver). It is possible to visualize the motion of the eardrum over time on the fast Valsalva movement at high resolution.

Algorithms↗
PubMed1997

Auditory event-related potentials in post- and prelingually deaf cochlear implant recipients.

The development of central auditory functions in cochlear implant (CI) patients was studied over six months of rehabilitation. Examinations were performed beginning with the first week after processor calibration, and in monthly follow-up sessions thereafter. The subjects were given a simple auditory perception task (detection of a 400 Hz and a 1450 Hz tone), as well as an oddball-paradigm (detection of one of the tones as a rare deviant). Auditory evoked potentials, reaction time and errors were recorded. Results from five patients, two postlingually deaf and three prelingually deaf CI recipients are shown. Generally, in the auditory evoked potentials of patients a shortening of N100 latency towards those of subjects with normal hearing was seen from month to month. However, in the prelingually deaf patients this effect was weaker and more variable over time. Three CI recipients showed a P300 component in the oddball-paradigm in correlation with their performance. Two prelingually deaf patients failed to show a P300 in the oddball-paradigm. For both components, the N100 and the P300 we found a larger spreading over the skull in the patients compared to a normal hearing person. The results show that from the very first days after initial processor fitting prelingually and postlingually deaf CI recipients may show cortical correlates of stimulus processing and discrimination. For some components of the auditory evoked potentials an initial temporal change but a maintained larger spreading over the skull was seen.

Cochlear Implantation↗
PubMed1996

[Amplitude modulation following response (AMFR)--a method for objective frequency specific audiologic diagnosis].

BACKGROUND: The objective evaluation of the hearing threshold below 1kHz by means of early auditory potentials leads to problems caused by the discrepancy between the required steep rise edge of stimulus and the frequency specificity of the potentials. Therefore the aim of this study was to evaluate the potential role of the AMFR as a diagnostic tool for the assessment of hearing below 1 kHz. METHOD: The threshold of the AMFR was compared to the behavioral threshold in 13 normal hearing subjects and 46 patients with hearing loss. The stimulus used was an amplitude-modulated tone at the carrier frequencies of 0.5 and 1 kHz, a modulation frequency of 40 Hz; the modulation depth was 80%. The introduction of an empiric detectibility criterion based on spectral analysis of the response curve allowed the investigator to minimize the examination time and objectify the interpretation of the response. Additional investigations by means of highpass-masking took place to estimate the frequency specificity of the AMFR. RESULTS: The results show a good correspondence of the AMFR threshold to the behavioral threshold. Depending on hearing loss the mean values of differences between AMFR threshold and behavioral threshold are 3 dB - 13 dB. The degree of correspondence was highest in the patients with the most severe hearing loss. An influence of underlying cause of the hearing loss could not be found. Additionally the frequency specificity of the response potential was proven with high-pass masking in normal hearing subjects. Masking with cut-off frequencies above the carrier frequencies had no influence on the response while masking at the carrier frequency resulted in a strong reduction of the response curve. CONCLUSIONS: The results show that the 40 Hz-AMFR is a suitable method for the objective frequency-specific assessment of hearing in adults. Problems in the clinical use of the AMFR are caused by the long investigation time and the dependence of the potentials on the state of wakeness.

Adolescent↗
PubMed1996

[Evaluation of deprivation manifestations of the auditory system in patients with unilateral middle ear deafness before and after surgical therapy].

BACKGROUND: This paper will discuss whether long term conductive hearing loss leads to late onset auditory deprivation as described in the literature in patients suffering from bilateral sensorineural hearing loss and fitted with monaural hearing aids. METHOD: The patients were examined using the Freiburg speech test in the undistorted and distorted forms (according to Dieroff 1985), and the pure tone threshold was ascertained for each patient. Thirty-six preoperative und postoperative results after tympanoplasty and stapes surgery were evaluated. Follow-up was performed six weeks and six months postoperatively. Twenty-one test persons with normal hearing were investigated. RESULTS: Comparison showed that the quotient obtained from undistorted and distorted tests is significantly higher in the affected patients. We even observed a highly significant improvement of this quotient, the speech recognition score (according to Bönninghaus/Röser), and the pure tone threshold after surgery. Seventy-eight percent of our patients showed an improved quotient, and 73% attained a normal value. But in only 29% of all cases did we see a symmetrical quotient in both ears in this period of time. In the statistical evaluation, we were unable to demonstrate a correlation between the patient's age at that moment, the age at the beginning of hearing loss, and this echo quotient. There is also no correlation between the absolute and relative change of the echo quotient and the duration of hearing loss. CONCLUSION: It was evident that the distorted Freiburg speech test is a good method to demonstrate the deprivation of the auditory system. We observed the improvement of the distorted Freiburger speech test at postoperative intervals of six weeks and six months. Hearing training should be applied after surgery in an effort to improve the hearing results.

Adolescent↗
PubMed1996

[Postmortem changes in ear canal resonance and tympanic membrane impedance in the human ear].

BACKGROUND: The human temporal bone preparation is a common model for research of physical processes of the ear canal and middle ear. In the past decade only a few reports were published discussing changes of the vibration behaviour of the tympanic membrane, as well as the ear canal resonance, during the time between death and preparation of the temporal bone. The aim of our study is to verify whether measurements at the temporal bone of dead humans can be really applied to the in vivo situation. METHODS: We investigated whether changes of the ear canal resonance and the vibration of the tympanic membrane depend on temperature and time after death. In a female human body we defined the resonance of the outer ear and the impedance of the tympanic membrane using a tympanometer and a real ear measurement system during nine hours post mortem. RESULTS: We were able to prove that before the preparation of the temporal bone none of the parameters changed significantly. CONCLUSIONS: In conclusion, the method of preserving the bone after its preparation is decisive for the validity of measurements at the isolated (post mortem) human temporal bone.

Acoustic Impedance Tests↗
PubMed1995

[Effect size on resonance of the outer ear canal by simulation of middle ear lesions using a temporal bone preparation].

By means of a model of the external and the middle ear it is possible to simulate various, exactly defined pathological conditions of the middle ear and to describe their influence on ear canal resonance. Starting point of the investigations are fresh postmortem preparations of 8 human temporal bones with an intact ear drum and a retained skin of the ear canal. The compliance of the middle ear does not significantly differ from the clinical data of probands with healthy ears. After antrotomy it is possible to simulate pathological conditions of the middle ear one after the other at the same temporal bone. The influence of the changed middle ear conditions on ear drum compliance, ear canal volume and on the resonance curve of the external ear canal was investigated. For example, the middle ear was filled with water to create approximately the same conditions as in acute serous otitis media. In this middle ear condition a significant increase of the sound pressure amplification was found, on an average by 4 decibels compared to the unchanged temporal bone model. A small increase in resonance frequency was also measured. The advantages of this model are the approximately physiological conditions and the constant dimensions of the external and middle ear.

Acoustic Impedance Tests↗
PubMed1995

[Surgical therapy of oropharyngeal carcinoma within the scope of interdisciplinary tumor surgery].

BACKGROUND: The results of the surgical therapy of patients with extensive squamous cell carcinoma of the oropharynx and their lymph node metastasis, postoperative follow-up, and rehabilitation depend on the collaboration between ear, nose, and throat surgeons and maxillofacial surgeons. Modern reconstruction techniques permit single-session surgical treatment with a reduced period of hospitalization. The most important therapeutic aim is to improve patient well-being. PATIENTS: Over a period of two years, 45 patients underwent the same surgical procedure. These patients were all in stages III or IV of their disease. RESULTS: This procedure consists of a temporary lateral osteotomy of the mandible with or without resection of the mandible, to provide broad exposure of the tumor of the oropharynx. Apart from the broad exposure, the advantage of this surgical method lies in simple reconstruction using a pedicled and microanastomosed flap. Internal fixation with six and four-hole titanium plates is a reliable method for restoring the stability of the mandible. In six patients, complications occurred in connection with the plate fixation. In four patients, we observed osteomyelitis of the fragment fissure or sequestration. Plate fracture and pseudarthrosis occurred in one patient each. CONCLUSIONS: In our clinical experience, the microvascular anastomosed radial flap proved to be the ideal free soft tissue transplant. One of its primary advantages is its plasticity and hence good post-therapeutic functional results. The jejunal flap has become less significant them the radial flap; the advantage of mucous membrane transfer is lost after radiation and a corresponding postoperative interval. In patients with large, voluminous defects, the use of myocutaneous flaps, especially from the latissimus dorsi, is still justified.

Adult↗
PubMed1994

[Clinical and catamnestic studies after oto- and rhinobasal skull fractures].

The large number of craniocerebral injuries with fractured bones entails an essential field of diagnostic and therapeutic activities for the hospital-based otorhinolaryngologist. It is only with the active involvement of experienced clinicians that paranasal sinuses can be inspected, lesions of the dura mater closed and functional structures of the petrous bone restored. Over a twelve-year period, 311 injuries of the base of the skull were treated in the Magdeburg Department of Otorhinolaryngology. Clinical findings, complications and therapeutic methods used during acute treatment, as well as permanent and late effects in patients with anterior and posterior skull base fractures were analyzed in a comparative approach. Despite early surgery of frontal base fractures, late sequelae have been extensive and resulted in far-reaching changes in patients injured. Temporal bone fractures have presented less problems following mainly conservative acute treatment, with late sequelae exclusively comprising local symptoms in the area of the fracture. Analysis of the present results of treatment demonstrates that otorhinolaryngologists, in cooperation with neurosurgeons, traumatologists, oral surgeons, ophthalmologists, neurologists and intensive care physicians, can efficiently and adequately treat fractures of the base of the skull.

Adolescent↗