PubMed Health⌕ Search

Biomedical subjects

S Holtmann

Publications and source records attributed to S Holtmann.

At least 19 recordsLinked to original sources
PubMed1995

[A new method for measuring internal ear circulation using colored microspheres].

The pathogenesis of sudden hearing loss is as yet unknown. Vascular disturbances are thought to play a major role, but they cannot be diagnosed clinically. We have therefore developed an animal model which allows measurements of the cochlear blood flow (CBF) and function. For CBF measurements a new technique based on coloured microspheres was developed. New Zealand rabbits were anaesthetised, ventilated and blood pressure and heart frequency were continuously monitored. 6 x 10(6) microspheres of one colour were injected in the left ventricle; different colours are available and allow multiple measurements. The amount of microspheres trapped in the capillary bed of the cochlea depends on the regional blood flow. An arterial reference blood sample makes it possible to calculate absolute values of the regional blood flow in the cochlea. The amount of microspheres trapped in the cochlea was determined microscopically after dissecting, dissolving and filtrating the cochlea. Measurements of the CBF in a control group (5 rabbits, 10 inner ears) at the beginning and after 120 minutes were performed. Mean CBF was 3.8 +/- 1.1 microliters/min and 4.3 +/- 1.3 microliters/min. The coloured microsphere technique allows repeated measurements of the CBF with good reproducibility and an acceptable standard deviation. CBF can be measured in absolute values, which is of advantage for determining a lower limit of the CBF for the cochlea function.

Animals↗
PubMed1994

[Surgical treatment of pediatric laryngeal stenosis in the area of the ring cartilage].

In the past 15 years, infants and children with laryngeal stenosis have also been successfully treated with laryngotracheoplasty. From 1991 to 1993 we performed a surgical treatment in 20 pediatric patients with subglottic stenosis. The anterior cricoid split procedure should always be considered in children who cannot be extubated before undergoing tracheotomy, especially because in case of failure there are no disadvantages for any further operative measurements. By modifying the technique described by Cotton and Seid (1980), we performed an endoscopically controlled anterior cricoid split in 5 children via an endolaryngeal approach. 4 of these patients were extubated within 10 days after using a nasotracheal tube for splinting the cricoid level. In 14 patients with a tracheostoma we used a modification of Réthi's division of the posterior lamina of the cricoid by the placement of a autogenous costal cartilage graft. A 6-week-period of stenting is required for sufficient healing and stability of the reconstructed airway.

Child↗
PubMed1994

[Endoscopic, 3-dimensional measurement of neoplasms and stenoses of the larynx and trachea].

Calculating the exact measures of laryngeal tumours will be crucial for the next generation of the TNM System. Furthermore, cross-sectional area and length of a laryngotracheal stenosis are of major interest for clinical management. It is the aim of this study to assess these parameters endoscopically in a more detailed and exact manner. For this purpose a Hopkins Endoscope (Karl Storz, Tuttlingen, Germany) and a slide caliper are combined. This new instrument is called laryngometer (Fig. 1a u. b). It helps to measure the lengths of a stenosis or neoplasm. In addition it defines the level of a given object and provides a standard in a two-dimensional video sequence. Thus the laryngometer allows to digitally analyse cross-sectional areas and distances as well as to evaluate craniocaudal parameters.

Child↗
PubMed1993

[Reconstruction of a malformed external ear by an endoprosthesis of porous polyethylene with an integrated suction system].

Complete reconstruction of the external ear is one of the most difficult tasks in plastic and reconstructive surgery. The risk of frame protrusion inherent in all alloplastic materials is reduced by using a new premoulded endoprosthesis with an integrated suction system. It consists of tissue-compatible porous polyethylene. A conventional suction drainage can be attached to a hollow canal system within the endoprosthesis that empties from defined spaces corresponding to the natural concavities of the external ear. In combination with a preceding expansion the overlying skin is then adapted evenly and completely to the frame by suction. As a result of this vacuum seromas and haematomas can be prevented. Furthermore, infections and pressure necroses due to matress sutures cannot develop. The use of this endoprosthesis obviates the removal of autogenous cartilage and all the complications and scars that are connected with this procedure. The frame itself is stable and has a relief that is largely similar to the natural form of the auricle. Thus, an aesthetically satisfying result can be achieved also in the hand of the surgeon who is not often engaged in this field of plastic surgery.

Adolescent↗
PubMed1993

[Clinical significance of cervico-ocular reactions].

Cervically induced eye movements consist of a nystagmus and a deviation of the mean eye position (shift). They show in relation to different neck torsion velocities maximum reactions at slow velocities. The clinical significance of these cervico-ocular reactions is discussed controversially. Therefore we investigated 40 healthy subjects without any neurootological findings, who, in addition, underwent a manual examination. The neck torsion test was performed automatically with quantifiable stimulus parameters and a complete head fixation by means of individual dental casts. It could be shown that at a constant chair velocity of 5 degrees/s every healthy subject exhibits cervical nystagmus and/or shift deviations. In comparison a group of 30 patients with an upper cervical spine syndrome also showed similar cervico-ocular reactions without significant difference. It can be concluded that a muscle hypertonus in the deep neck region does not lead to pathological, cervically induced eye movements and that the cervical nystagmus itself is not a pathognomonic sign for cervical, proprioceptive vertigo.

Adult↗
PubMed1991

[Leiomyosarcoma of the external ear canal].

We report on a 45-year-old male patient with the signs of exophytic, obstructive and painless tumour of the right external auditory canal developed within a period of about 3 months. The tumour was completely removed in local anaesthesia and histologically found to be a leiomyosarcoma. The only possible origin of this lesion might be the smooth muscle cells of the local blood vessels or the mm. arrectores pilorum.

Ear Canal↗
PubMed1989

Cervical receptors and the direction of body sway.

A study was performed to determine whether the predominant direction of body sway is influenced by changes of head-to-trunk position. A group of ten patients suffering from acute unilateral vestibular loss was compared with a group of ten healthy subjects. Body sway was assessed by measurement on a posture platform. Center-of-force stabilograms were recorded with the subjects' eyes closed. After a baseline interval in the normal head-to trunk orientation, the head was torsioflexed with respect to the trunk and the locus of the center-of-force further assessed over a defined interval. It was observed that the patient group manifested a systematic translation of the direction of body sway that was associated in a consistent manner with the unilateral deficit. This translation occurred synchronously with head torsioflexion and could also be reproduced when turning the trunk with the head fixed, so that a semicircular canal influence could be excluded. It appears that cervical proprioceptive input to the central vestibular system is responsible for the effect observed.

Head↗
PubMed1989

[Cervical afferent fibers and their relation to the regulation of equilibrium].

Experiments with stimulation or denervation of cervical dorsal roots in animals have shown that input of the deep neck region is important for orientation, upright posture and the control of eye movements. Muscle spindles seem to play a dominant role as receptors for neck movements. Different ascending pathways project to the central nervous system and the signals interact with visual and vestibular stimuli. Cervical afferences provide a stabilization of the trunk during head movements because neck reflexes cancel labyrinthine reflexes. Posturographic measurements with head extension manoeuvres however did not turn out to be helpful in dizzy patients. Cervically induced eye movements are part of the complex head-eye coordination. The characteristics of cervico-ocular reactions are described. They show in relation to different neck torsion velocities a tuning curve with maximum reactions at slow velocities. Therefore the velocity of trunk rotation is, among others, an important factor when stimulating cervical afferences. The results from literature as well as own experiments show that there exists no method as yet that could yield positive evidence of cervical dizziness.

Afferent Pathways↗
PubMed1989

[Lyme borreliosis and its significance for the ENT physician].

Lyme disease is a tick-borne multisystemic Borrelia infection to which the following diseases belong: erythema migrans, lymphadenosis benigna cutis, lymphocytic meningoradiculitis (Bannwarth's syndrome), Lyme-arthritis and acrodermitis chronica atrophicans. The infection rate of ticks with Borrelia Burgdorferi in Germany amounts to 13.6% compared to the infection with the European spring summer meningoencephalitis virus with 1.1%. Recent investigations show that lipopolysaccharides and interleukin-1 play an important role in the pathogenesis of Lyme disease. Lipopolysaccharides (LPS) are a constitutive part of the outer wall of gram negative bacteria. Its biological activities include pyrogenicity, mitogenicity for lymphocytes and the induction of interleukin-1 (IL-1). IL-1 is the major macrophage-derived immunoregulatory protein. Lyme disease is characterized by a variety of symptoms which could be explained by the effects of IL-1 on host systems. These symptoms include: fever, malaise, erythema migrans and arthritis. The clinical course can be divided into three stages. Erythema migrans, lymphadenosis benigna cutis and general symptoms characterize the first stage. In the second stage disorders of the heart and the neurological system may follow including Bannwarth's syndrome. 60% of the patients develop facial palsy and 30% of these patients bilateral palsy. In 40% of all cases the facial palsy is the only motor disorder. Other cranial nerves can also be affected. The third stage consists of the Lyme-arthritis, acrodermitis chronica atrophicans and encephalomyelitis. The determination of specific spirochetal antibodies in serum and cerebrospinal fluid (CSF) is the most valuable diagnostic aid for this borreliosis. The CSF examination may also be helpful.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis, Differential↗
PubMed1989

[In vivo 31P magnetic resonance spectroscopy and MRI in patients with superficial tumors].

Simultaneous 31P-MR spectroscopy (MRS) and MR imaging (MRI) of 10 patients suffering from superficial tumours like carcinoma, lymphoma and adenoma, revealed significantly enhanced concentrations of phosphomonoester, phosphodiester and inorganic phosphorus in the tumour, whereas the concentration of phosphocreatine was lower in comparison to muscle tissue. In all tumours the pH showed a slight alkaline shift. The existing of necrotic regions detected by MRI was accompanied by an increase of inorganic phosphorus in the spectra. A follow-up study of a patient with a lymphoma during chemotherapy showed a tumour regression, whereas the spectra indicated a continuous approach of tumour values to the muscle values.

Contrast Media↗
PubMed1989

Cervico-ocular eye movements in relation to different neck torsion velocities.

Rotation of the trunk with a fixed head causes isolated stimulation of cervical afferent input. Eleven patients with marked cervico-ocular reactions (COR) were selected. A neck torsion test (NTT) was performed with the help of a special apparatus. The resulting cervically induced eye movements consisted of two components. In addition to a cervical nystagmus, with its slow, compensatory phase, a deviation of the mean eye position (shift) in an anticompensatory direction, opposite to trunk rotation was observed. The COR in relation to different neck torsion velocities distinctly showed a tuning curve with maximum reactions between 4 degrees/s and 9 degrees/s. Above these values, a strong decrease in COR resulted. The optimal working range vastly differs from that of the vestibulo-ocular reflex (VOR).

Adult↗