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Biomedical subjects

Karl-Bernd Hüttenbrink

Publications and source records attributed to Karl-Bernd Hüttenbrink.

At least 19 recordsLinked to original sources

Mechanical obstruction of the olfactory cleft reveals differences between orthonasal and retronasal olfactory functions.

Following up on recent observations in patients with nasal polyposis (NP), the present study aimed to investigate whether a mechanical obstruction of the anterior olfactory cleft (OC) would produce differential effects on orthonasal and retronasal olfactory functions. To this end, we studied 33 healthy subjects in a randomized trial. Sponges with high content of saline were either placed in the OC or on the respiratory epithelium, such that this was blinded to both subject and observer. The results indicated that orthonasal (P = 0.04) but not retronasal (P = 0.15) olfactory identification ability was lower when the OC was blocked. This confirms the idea that differences between orthonasal and retronasal olfactory functions, as observed in NP patients, are, at least to some degree, due to mechanical obstruction of the anterior portion of the OC. The present data also suggest that mechanical obstruction is a means to induce reversible hyposmia void of side effects which can be performed in a blinded fashion. This might become a valuable model of hyposmia for future investigations.

Adult↗

Effects of radiotherapy on olfactory function.

BACKGROUND AND PURPOSE: Changes in olfactory function have been reported in patients receiving significant doses of radiation to the olfactory epithelium. Aim of this study was to investigate severity and time course of changes in olfactory function in patients irradiated for tumours of the head and neck region. MATERIAL AND METHODS: Forty-four patients receiving radiotherapy (RT) for tumours in the area of the head and neck participated (16 women, 28 men; age 11-81 y; mean 55 y). Olfactory function was measured before and bi-weekly during RT for 6 weeks. A subgroup (25 patients) was followed for 12 months. Patients were divided into two groups according to the dose to the olfactory epithelium. Twenty-two patients ('OLF group') had radiation doses to the olfactory epithelium between 23.7 and 79.5 Gy (median 62.2 Gy). In the 22 patients of the 'non-OLF group' the dose applied to the olfactory epithelium was significantly lower (2.9-11.1 Gy, median 5.9 Gy). Total tumour dose (30-76.8 Gy), age, sex distribution, and baseline chemosensory function were not significantly different between groups. Testing was performed for odour identification, odour discrimination, and olfactory thresholds. RESULTS: Odour discrimination, but not odour identification or odour threshold, was significantly decreased 2-6 weeks after begin of therapy in the OLF group. In addition, a significant effect of the radiation dose was observed for odour discrimination. More than 6 months after therapy, OLF group patients had significantly lower odour identification scores compared to the non-OLF group. CONCLUSION: As indicated through the non-significant change of olfactory thresholds, the olfactory epithelium is relatively resistant against effects of radiation. It is hypothesized that RT has additional effects on the olfactory bulb/orbitofrontal cortex responsible for the observed changes of suprathreshold olfactory function.

Adolescent↗

Extension of intracranial thrombosis after unilateral dissection of the internal jugular vein.

OBJECTIVE: Resection of the internal jugular vein can be necessary in cases of radical neck dissection or even in cases involving benign neoplasms such as glomus tumors. According to the triad described by Virchow (ie, stasis of blood flow, damage to the endothelium, and changes in hemostasis), the development of a thrombosis in the venous vessels superior to the resected internal jugular vein seems to be possible. The aim of this study was to determine the extension of possible intracranial thrombosis after wound healing. DESIGN: A total of 17 patients requiring resection of the internal jugular vein were evaluated prospectively using magnetic resonance imaging and 2-dimensional (time-of-flight) magnetic resonance angiography after the surgical treatment. Preoperative magnetic resonance images were obtained in all 17 patients for staging purposes as well as to exclude preoperative thrombosis of the internal jugular vein. Sixteen patients had malignant tumors, and 1 patient had a glomus tumor. RESULTS: Intracranial thrombosis with thrombosis of the sigmoid sinus was found in 4 patients, and thrombosis of the transverse sinus was found in 3 patients. There were no complications such as intracranial hemorrhage or signs of increased intracranial pressure in any patients. There was no evidence of intracranial thrombosis in 10 cases. In these cases, thrombosis of the venous vessels superior to the resected vein ranged from none to complete thrombosis of the superior bulb of the internal jugular vein. After unilateral resection of the internal jugular vein, the venous blood leaves the brain mainly via the venous network of the contralateral side of the neck. CONCLUSIONS: Although intracranial thrombosis of the sigmoid or transverse sinus seems to occur more frequently than was previously thought, intracranial complications such as venous infarction or increased intracranial pressure appear to be very rare. After unilateral radical neck dissection, the venous blood leaves the brain mainly via the venous system of the other side of the neck and the ipsilateral collateral veins.

Aged↗

Morphological and radiologic evaluation of the human nasopalatine duct.

In several mammals, a direct connection between the nasal cavity and the oral cavity is a common finding. The structure is named the nasopalatine duct (NPD). It has been hypothesized to be functional in terms of transportation of odorants from the oral cavity to the nasal cavity. In humans, the NPD exists during embryological development. The connection between the nasopalatine infundibulum and the incisive fossa is typically closed at the time of birth. We present the case of a 24-year-old man who presented with a persistent NPD. By means of a thin, soft tube, it was possible to probe the NPD. Magnetic resonance imaging revealed a bony gap between the hard palate and the alveolar process of the maxillary bone with a length of 16 mm and a width of 6 mm. In light of the literature of the past 500 years, this represents a rare finding of a persistent NPD.

Adult↗

[Clinical aspects of dysosmia and presentation of European Olfactory Test of "sniffin sticks": a review].

The medical community has neglected olfactory dysfunction for a long time. However, over the last two decades, remarkable progress has been made in terms of understanding the sense of smell and both the assessment and diagnosis of olfactory dysfunction. Currently, there are only a few validated olfactory tests. The most commonly used one is the University of Pennsylvania Smell Identification Test. Owing to its cultural biases, this test is mostly used in the United States. "Sniffin' Sticks" are one of the first European tests to be widely used. Since their development in 1996, they have been applied in numerous studies and have found increasing use in otolaryngology clinics. The goal of this article is to present Sniffin' Sticks and to provide a review of clinical olfactory research during recent years.

Bacterial Infections↗

Titanium clip prosthesis.

OBJECTIVE: Prostheses for the reconstruction of a defective ossicular chain should be stable and firmly anchored to the ossicular remnants. This will prevent a defective connection from causing diminished sound transmission efficiency and will keep the prosthesis from tilting or even losing contact, which would result in a sound transmission block. Through temporal bone experimentation, we have consequently developed a very lightweight titanium prosthesis, which is fastened onto the stapes head with a clip mechanism. METHODS: When temporal bone experiments using laser Doppler vibrometry confirmed that the prosthesis functioned well acoustically and when luxation experiments proved that it could be safely used without the risk of stapes dislocation, the prosthesis was used in a clinical application within an observational study. The University of Dresden Otorhinolaryngological Hospital as well as seven surgeons from five other hospitals participated in the study. RESULTS: The results of 133 operations showed that, in over 90% of the cases, the prosthesis could be implemented without problems and with good mechanical stability. The first acoustical results obtained during the first year from 49 patients showed a sound transmission improvement range from 12 dB to 14 dB. CONCLUSION: With the clip prosthesis, it seems possible to further improve defective middle ear function, which would allow the patient to regain social hearing after middle ear reconstruction. The reliability of the fastening is an innovation. Revision operations showed a stable prosthesis-stapes complex in the middle of a recurring cholesteatoma and the prosthesis could always be easily pulled from the stapedial suprastructure.

Auditory Threshold↗

[Testing the sense of smell using validated procedures].

There is a growing interest into the investigation of smell disorders in both research and clinical practice. For psychophysical ("subjective") investigations related to the sense of smell a variety of test kits are available, namely the various "Sniffin' Sticks" kits, the UPSIT (University of Pennsylvania Smell Identification Test) or the CCSIT (Cross-Cultural Smell Identification Test). Recording of olfactory evoked potentials (OEPs) and respiration olfactometry can be used for diagnosing smell dysfunctions in a more objective way.

Humans↗

[Testing the sense of taste using validated procedures].

Psychophysical tests related to the sense of taste are usually less complex than those of the sense of smell. In addition to global tests a regional examination of the sense of taste might be indicated to search for nerve lesions. There are numerous validated psychophysical tests available based on the administration of liquid or solid substrates. The use of electrical currents (electrogustometry) is especially feasible for a rapid regional testing. The registration of gustatory event-related potentials to objectify results from psychophysical examination is possible although limited to a few centers world-wide.

Electrophysiology↗

Change of voice characteristics during +3 Gz acceleration.

BACKGROUND: This study was performed to test the feasibility of an experimental approach for assessing voice changes during exposure to increased +Gz acceleration. Such changes are probably due to mechanical alterations of the structures involved in voice production. This may be relevant to automatic speech analysis for flight control. Because voice control by means of auditory feedback may compensate for acceleration effects, the investigations included conditions with masked auditory feedback. METHOD: Four male subjects read standard speech test material while seated in a human centrifuge both during sustained +3 Gz acceleration and in a reference condition. Both test runs were repeated with masking of the auditory feedback by a white noise presented via headphones. Microphone and acceleration signals were recorded on a PC-based dynamic signal acquisition board. Long-time average spectra (LTAS), fundamental frequency (F0), and the frequency of the first, second, and third formant (F1, F2, F3) of the vowels /a/, /o/, and /i/ were extracted from the microphone signal for the different conditions. RESULTS: LTAS clearly differed between the masking conditions, but not between reference and +3 Gz conditions. F0 clearly rose with auditory masking and showed a small increase under +3 Gz acceleration. Several effects of +3 Gz acceleration on formant frequencies were found, all of rather small magnitude. Increased acceleration lowered F2 for the vowel /i/. A decrease of F3 was observed for vowels /i/ and /o/. CONCLUSION: This pilot study has shown the feasibility of an experimental approach to assessing voice changes during exposure to increased +Gz acceleration. Exposure to +3 Gz showed small effects on FO and several formant frequencies. A definitive forthcoming study should assess the significance of these effects by investigating a greater number of subjects during exposure to acceleration higher than +3 Gz.

Adult↗

Effects of olfactory function, age, and gender on trigeminally mediated sensations: a study based on the lateralization of chemosensory stimuli.

The present investigation aimed to compare trigeminal nasal function of anosmic and hyposmic patients to healthy controls. Further, we aimed to study effects of age and gender on trigeminally mediated sensations following intranasal chemosensory stimulation. Participants were 35 patients with olfactory dysfunction (n=13: functional anosmia; n=22: hyposmia; age 28-69 years, mean age 56 years). Their results were compared with 17 normosmic subjects (28-82 years, mean 52 years). To analyze effects of age and gender in healthy subjects, an additional 24 healthy subjects were included (19-27 years; mean 24 years). Olfactory function was assessed using the 'Sniffin' Sticks' test kit (butanol odor threshold, odor discrimination, odor identification). The subjects' ability to lateralize odors was investigated for benzaldehyde and eucalyptol. Patients with olfactory dysfunction had lower scores in the lateralization task than controls (P<0.001) indicating decreased trigeminal sensitivity. Among anosmic patients scores were not different in relation to different causes of olfactory dysfunction (P>0.29). There was a weak, but significant, correlation between localization of eucalyptol and duration of olfactory dysfunction (P=0.017). When investigating normosmic subjects only, no gender-related difference was apparent for lateralization scores. However, older subjects had lower scores than younger ones (P<0.01). Results of partial correlational analyses controlling for age suggested a relation between the trigeminal and the olfactory systems. In conclusion, results of the present study indicate that patients with olfactory dysfunction have lower trigeminal sensitivity compared with normosmic controls. This seems to be independent of the cause of olfactory loss. The deficit appears to improve with duration of the olfactory dysfunction, possibly indicating adaptive mechanisms. Further, the data suggest an age-related decrease of intranasal trigeminal sensitivity in healthy subjects. Analyses additionally indicate a correlation between olfactory and trigeminal sensitivity.

Adult↗

Assessment of olfactory function and androstenone odor thresholds in humans with or without functional occlusion of the vomeronasal duct.

To obtain information on the possible role of the vomeronasal duct (VND) in odor perception and human pheromone detection, the present study investigated different aspects of olfactory function, including thresholds for androstenone in adults with or without detectable VNDs. The study also examined correlations between detection thresholds of androstenone odor and general olfactory function. Subjects' olfaction was assessed with tests for odor identification, odor discrimination, and phenyl ethyl alcohol odor threshold. Measurements were performed on 1 side only, with and without covering the VND. Subjects with or without detectable VNDs did not differ in olfactory sensitivity or androstenone odor thresholds. A small but significant correlation was found between detection thresholds of androstenone and general olfactory function. Finally, covering of the VND did not affect olfactory function or androstenone sensitivity. Results suggest that the human VND does not play a major role in sensitivity toward odorants or the perception of androstenone.

Adolescent↗

Biomechanics of stapesplasty: a review.

OBJECTIVE: The replacement of an otosclerotic fixed stapes by a prosthesis significantly modifies the function of the normal ossicular chain. Because the ear works as a pressure receptor, a piston prosthesis will both modify the sound pressure transmission and respond to the ambient air pressure changes in a different way than the normal stapes. Both aspects, the acoustic transmission and the displacements of the prosthesis with variations of atmospheric pressures, are reviewed. CONCLUSION: The diameter of a piston should not be smaller than 0.4 mm and it should be inserted into a significantly larger perforation of the footplate. A low mass is advantageous for transmission of higher frequencies. Firm attachment at the processus lenticularis is necessary for effective energy transmission. This is of paramount importance in a malleovestibulopexy because of the oblique position of the piston. A piston can be displaced up to 0.5 mm in the vestibule at ambient air pressure changes, as it is not attached to the annular ligament. These large movements explain why a short piston can be lifted out of the footplate fenestration (i.e., after sneezing) and why a piston with excessive length can impale the structures of the membranous labyrinth, causing vertigo (i.e., in a retraction of the tympanic membrane). However, flying or diving should be allowed generally, provided that a test with tympanometry, applying variable pressures of +/- 400 mm H(2)O, is tolerated without evoking vertigo.

Atmospheric Pressure↗

Effects of antihistamines on leukotriene and cytokine release from dispersed nasal polyp cells.

In this study the effects of antihistamines on the release of eicosanoids and the pro-inflammatory cytokine tumor necrosis factor alpha (TNF alpha) were compared. Enzymatically dispersed cells from human nasal polyps served as an in vitro model of chronic respiratory mucosal inflammation. Nasal polyp cells (2 x 10(5)/ml) were sensitized with human IgE pre-incubated azelastine (CAS 58581-89-8), terfenadine (CAS 50679-08-8), levocabastine (CAS 79516-68-0) or cetirizine (CAS 83881-51-0), and stimulated with anti-human immunoglobulin E (IgE). Thromboxane B2 (TBX2) and leukotriene C4 (LTC4) were measured by radioimmunoassay (RIA), TNF alpha by enzyme-linked immunosorbent assay (ELISA). Data represent mean values of % inhibition estimated from the untreated positive control or mean IC50 (n = 5). Azelastine and terfenadine inhibited TNF alpha release with IC50 values of 6.2 mumol/l and 4.3 mumol/l, respectively. Terfenadine reduced TXB2 release by 37 +/- 15%, and LTC4 release was decreased by azelastine and terfenadine very potently by 86% and 100%, respectively. Azelastine shows anti-inflammatory properties in therapeutically relevant concentrations as assessed by its ability to reduce TNF alpha release as well as its ability to inhibit LTC4 production in allergically stimulated human nasal polyp cells.

Cytokines↗

Acoustic properties of different cartilage reconstruction techniques of the tympanic membrane.

OBJECTIVES/HYPOTHESIS: The use of cartilage in reconstruction of the tympanic membrane has been established especially in cases such as tubal dysfunction and adhesive processes. Cartilage offers the advantage of higher mechanical stability compared with membranous transplants but may alter the acoustic transfer characteristics of the graft. Apart from material properties, it can be assumed that, also, the microsurgical reconstruction technique might influence the sound transmission properties of the reconstructed tympanic membrane. The purpose of the study was to investigate the acoustic transfer characteristics of different cartilage transplants being typically used in different reconstruction techniques of the tympanic membrane. METHODS: Cartilage plates of different thicknesses (1.0, 0.7, 0.5, and 0.3 mm), cartilage palisades, and cartilage island transplants of varying size were investigated by means of an ear canal-tympanic membrane model. In contrast to former single-point measurements, sound-induced vibrational amplitudes of the entire transplant were measured by scanning laser Doppler vibrometry (measuring points, n = 133) (PSV-200, Polytec, Waldbronn, Germany). Frequency response functions (displacement vs. sound pressure) of all measured points were determined in the frequency range of 200 Hz to 4 kHz for the different transplants. RESULTS: Cutting thick cartilage transplants into thin plates or palisades decreased the first resonance frequency and increased its amplitude, reflecting improved sound transmission properties of the transplant. From an acoustical point of view, the 0.5-mm cartilage plate seems preferable compared with the palisade technique. Cartilage island techniques showed vibration characteristics superior to plate or palisade techniques. CONCLUSIONS: Apart from material characteristics, the sound transmission properties of the reconstructed tympanic membrane are strongly influenced by the reconstruction technique. The choice of the surgical technique should consider requirements based on mechanical stability and acoustic transfer characteristics of the transplant.

Acoustics↗