[Antiseptics in otorhinolaryngology-a substance overview]

For preoperative skin antisepsis, alcohol-containing iodine solutions and octenidine are suitable. For wound antisepsis, polyhexanide and hypochlorous acid (HOCL) are also available, but only PVP-iodine and HOCL can be applied to cartilage. Chlorhexidine should only be used as mouth- and bodywash for Staphylococcus aureus (MRSA) decolonization. For the many other throat antiseptics, evidence of clinical efficacy is lacking. For decolonization of the nares, polyhexanide and octenidine are available as nasal gels, but these are inferior to mupirocin for MRSA decolonization. PVP-iodine and HOCL are safe to use for nasal irrigation, but only HOCL has proven effective to improve symptoms of chronic rhinosinusitis. All antiseptics exhibit a certain ototoxicity. With an intact eardrum, acetic acid-containing eardrops can be used to prevent and treat external otitis and myringitis. When the eardrum is perforated, only alcohol-free PVP-iodine and HOCL may be used.

Randomized, placebo-controlled study on efficacy, safety and tolerability of drug-induced defibrinogenation for sudden sensorineural hearing loss: the lessons learned

PURPOSE

Disturbance of cochlear microcirculation is discussed as final common pathway of various inner ear diseases. Hyperfibrinogenemia causing increased plasma viscosity is a possible factor for a critical reduction of cochlear blood flow that might lead to sudden sensorineural hearing loss (SSHL). The aim was to determine the efficacy and safety of drug-induced defibrinogenation by ancrod for SSHL.

METHODS

Double-blind, randomized, placebo-controlled, multicenter, parallel group, phase II (proof-of-concept) study (planned enrollment: 99 patients). Patients received an infusion of ancrod or placebo (day 1) followed by subcutaneous administrations (day 2, 4, 6). Primary outcome was the change in pure tone audiogram air conduction average until day 8.

RESULTS

The study was terminated early due to slow recruiting (31 enrolled patients: 22 ancrod, 9 placebo). A significant improvement of hearing loss was registered in both groups (ancrod: - 14.3 dB ± 20.4 dB, - 39.9% ± 50.4%; placebo: - 22.3 dB ± 13.7 dB, - 59.1% ± 38.0%). A statistically significant group-difference was not detected (p = 0.374). Placebo response of 33.3% complete and 85.7% at least partial recovery was observed. Plasma fibrinogen levels were reduced significantly by ancrod (baseline: 325.2 mg/dL, day 2: 107.2 mg/dL). Ancrod was tolerated well, no adverse drug reaction was of severe intensity, no serious adverse events occurred.

CONCLUSION

Ancrod reduced fibrinogen levels that support its mechanism of action. The safety profile can be rated positively. Since the planned number of patients could not be enrolled, no efficacy conclusion can be drawn. The high rate of placebo response challenges clinical trials for SSHL and needs to be considered in future investigations. Trial registrations This study was registered in the EU Clinical Trials Register, EudraCT-No. 2012-000066-37 at 2012-07-02.

Calculated parenteral initial treatment of bacterial infections: Infections in the ear, nose, throat and mouth and jaw area

This is the sixth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter deals with the antibacterial treatment of more severe infections of the ear, the nose, the throat and the maxillofacial region, including odontogenic and salivary gland infections.

Microbiome and Culture Based Analysis of Chronic Rhinosinusitis Compared to Healthy Sinus Mucosa

The role of bacteria in chronic rhinosinusitis (CRS) is still not well understood. Whole microbiome analysis adds new aspects to our current understanding that is mainly based on isolated bacteria. It is still unclear how the results of microbiome analysis and the classical culture based approaches interrelate. To address this, middle meatus swabs and tissue samples were obtained during sinus surgery in 5 patients with CRS with nasal polyps (CRSwNP), 5 patients with diffuse CRS without nasal polyps (CRSsNP), 5 patients with unilateral purulent maxillary CRS (upm CRS) and 3 patients with healthy sinus mucosa. Swabs were cultured, and associated bacteria were identified. Additionally, parts of each tissue sample also underwent culture approaches, and in parallel DNA was extracted for 16S rRNA gene amplicon-based microbiome analysis. From tissue samples 4.2 ± 1.2 distinct species per patient were cultured, from swabs 5.4 ± 1.6. The most frequently cultured species from the swabs were Propionibacterium acnes, Staphylococcus epidermidis, Corynebacterium spp. and Staphylococcus aureus. The 16S-RNA gene analysis revealed no clear differentiation of the bacterial community of healthy compared to CRS samples of unilateral purulent maxillary CRS and CRSwNP. However, the bacterial community of CRSsNP differed significantly from the healthy controls. In the CRSsNP samples Flavobacterium, Pseudomonas, Pedobacter, Porphyromonas, Stenotrophomonas, and Brevundimonas were significantly enriched compared to the healthy controls. Species isolated from culture did not generally correspond with the most abundant genera in microbiome analysis. Only Fusobacteria, Parvimonas, and Prevotella found in 2 unilateral purulent maxillary CRS samples by the cultivation dependent approach were also found in the cultivation independent approach in high abundance, suggesting a classic infectious pathogenesis of odontogenic origin in these two specific cases. Alterations of the bacterial community might be a more crucial factor for the development of CRSsNP compared to CRSwNP. Further studies are needed to investigate the relation between bacterial community characteristics and the development of CRSsNP.

Reduction of olfactory sensitivity during normobaric hypoxia

OBJECTIVE

Acute mountain sickness (AMS) is caused by a low partial pressure of oxygen and may occur above 2500m. The aim of this research was to evaluate olfactory and gustatory abilities of healthy subjects during baseline conditions and after seven hours of normobaric hypoxia.

METHODS

Sixteen healthy subjects were assessed using the Sniffin' Sticks, as well as intensity and pleasantness ratings. Gustatory function was evaluated utilizing the Taste Strips. Experiments were carried out under baseline conditions (518m altitude) followed by a second testing session after seven hours of normobaric hypoxia exposure (comparable to 4000m altitude).

RESULTS

During normobaric hypoxia olfactory sensitivity and intensity estimates were significantly reduced.

CONCLUSIONS

We conclude that normobaric hypoxia leads to a significant decrease of olfactory sensitivity and intensity ratings.

Diode laser versus radiofrequency treatment of the inferior turbinate - a randomized clinical trial

BACKGROUND

Laser and radiofrequency induced volume reduction of the inferior turbinates are frequently used treatment modalities. Which of both is superior, however, is not clear to date due to a lack of controlled prospective studies. Here, we compare both methods regarding improvement of nasal breathing, complications, patient comfort and wound healing.

METHODOLOGY

Prospective, randomized, single-blinded clinical trial with intra-individual design. After randomization, one side of the nose was treated with a 940nm diode laser and the other side with bipolar radiofrequency therapy. Pre- and postoperative evaluation was performed using visual analogue scales, nasal endoscopy and objective measurements of nasal patency.

RESULTS

Of 27 enrolled patients, 26 completed the protocol. No severe complications were observed. Intraoperative discomfort was significantly more severe on the radiofrequency side. After three months, a significant reduction of nasal obstruction was observed for laser treatment and radiofrequency therapy with no significant difference between them. Objective parameters did not improve significantly. When asked which treatment modality they would chose again 50 % of the patients decided for radiofrequency treatment, 23 % for laser treatment, and 19 % for both.

CONCLUSION

DLVR and RFVR are well-tolerated treatment modalities and both significantly reduce the degree of nasal obstruction in patients with hypertrophic inferior turbinates. There was no significant difference between both treatment modalities regarding efficiency.

Labial Salivary Glands in Infants: Histochemical Analysis of Cytoskeletal and Antimicrobial Proteins

Human labial glands secrete mucous and serous substances for maintaining oral health. The normal microbial flora of the oral cavity is regulated by the acquired and innate immune systems. The localization and distribution of proteins of the innate immune system were investigated in serous acinar cells and the ductal system by the method of immunohistochemistry. Numerous antimicrobial proteins could be detected in the labial glands: β-defensin-1, -2, -3; lysozyme; lactoferrin; and cathelicidin. Cytoskeletal components such as actin, myosin II, cytokeratins 7 and 19, α- and β-tubulin were predominantly observed in apical cell regions and may be involved in secretory activities.

Atmospheric Pressure and Onset of Episodes of Menière's Disease - A Repeated Measures Study

Background

External changes of air pressure are transmitted to the middle and inner ear and may be used therapeutically in Menière’s disease, one of the most common vertigo disorders. We analyzed the possible relationship of atmospheric pressure and other meteorological parameters with the onset of MD vertigo episodes in order to determine whether atmospheric pressure changes play a role in the occurrence of MD episodes.

Methods

Patients of a tertiary outpatient dizziness clinic diagnosed with MD were asked to keep a daily vertigo diary to document MD episodes (2004–2009). Local air pressure, absolute temperature and dew point temperature were acquired on an hourly basis. Change in meteorological parameters was conceptualized as the maximum difference in a 24 hour time frame preceding each day. Effects were estimated using additive mixed models with a random participant effect. We included lagged air parameters, age, sex, weekday and season in the model.

Results

A total of 56 persons (59% female) with mean age 54 years were included. Mean follow-up time was 267 days. Persons experienced on average 10.3 episodes during the observation period (median 8). Age and change in air pressure were significantly associated with vertigo onset risk (Odds Ratio = 0.979 and 1.010). We could not show an effect of sex, weekday, season, air temperature, and dew point temperature.

Conclusions

Change in air pressure was significantly associated with onset of MD episodes, suggesting a potential triggering mechanism in the inner ear. MD patients may possibly use air pressure changes as an early warning system for vertigo attacks in the future.

Diode laser versus radiofrequency treatment of the inferior turbinate - a randomized clinical trial

BACKGROUND

Laser and radiofrequency induced volume reduction of the inferior turbinates are frequently used treatment modalities. Which of both is superior, however, is not clear to date due to a lack of controlled prospective studies. Here, we compare both methods regarding improvement of nasal breathing, complications, patient comfort and wound healing.

METHODOLOGY

Prospective, randomized, single-blinded clinical trial with intra-individual design. After randomization, one side of the nose was treated with a 940nm diode laser and the other side with bipolar radiofrequency therapy. Pre- and postoperative evaluation was performed using visual analogue scales, nasal endoscopy and objective measurements of nasal patency.

RESULTS

Of 27 enrolled patients, 26 completed the protocol. No severe complications were observed. Intraoperative discomfort was significantly more severe on the radiofrequency side. After three months, a significant reduction of nasal obstruction was observed for laser treatment and radiofrequency therapy with no significant difference between them. Objective parameters did not improve significantly. When asked which treatment modality they would chose again 50 % of the patients decided for radiofrequency treatment, 23 % for laser treatment, and 19 % for both.

CONCLUSION

DLVR and RFVR are well-tolerated treatment modalities and both significantly reduce the degree of nasal obstruction in patients with hypertrophic inferior turbinates. There was no significant difference between both treatment modalities regarding efficiency.

Comparative Study between the Surgeon's Intraoperative Evaluation and Histopathology for Diagnosis of Laryngeal Lesions

Objective. To compare the surgeon's evaluation and histopathology for diagnosis of laryngeal lesions. Material. A clinical survey was distributed to laryngeal surgeons, ENT clinicians, and students in 2013 at the Department of Otorhinolaryngology in Rostock. Participants were asked to anonymously identify laryngeal pathologies and to assess the severity of the lesion starting from hyperplasia and inflammation over moderate dysplasia to early laryngeal cancer. Images of similar clinical laryngeal lesions were demonstrated in a multiple-choice modus to assess the surgeon's intraoperative evaluation. The questionnaires were digitally processed and evaluated. The results were correlated with histopathology and compared between experienced laryngeal surgeons, clinicians inexperienced in laryngeal surgery, and medical students from the Medical Faculty of the University of Rostock. Results. Sensitivity and specificity varied among the various groups, being highest in experienced laryngeal surgeons. In this group, sensitivity, specificity, positive and negative predictive value, and accuracy were 85%, 56%, 44%, 90%, and 65%, respectively. In 4% and 31%, laryngeal disease was underdiagnosed and overdiagnosed, respectively. In this group, Kappa statistics resulted in Kappa 0.32 (P < 0.001). Conclusion. This clinical survey clearly demonstrates that conformity between histopathology and evaluation of the laryngeal lesion depends on the surgeon's experience.

[Inpatient vs. outpatient costs analysis of septumplasty in Germany]

The septumplasty is realized inpatient and outpatient in different countries. Caused by the pressure of reduction of expenses there is the question of the economic benefit if done outpatient in Germany. A comparison of the inpatient and outpatient gratification will be done. There is a yearly potential of cost reduction of 180 million euro, if the operation would be done as an outpatient procedure. From the hospital view actual there is no economical recommendation doing an outpatient septumplasty caused by the poor outpatient remuneration. That's why an adjustment of the outpatient remuneration should be done. Actual there is no medical or economical recommendation doing the septumplasty as an outpatient procedere.

Specific stressors in endonasal skull base surgery with and without navigation

The goal of modern organizational psychology is to recognize, anticipate and finally avoid stress situations. The aim of this study was to measure objectively the mental and physical demands during transnasal surgery with and without the aid of a navigation system. Forty endonasal surgeries (20 with and 20 without navigation, not blinded and not randomized) done by four different experienced rhinosurgeons (>250 FESS procedures done) were included. The heart rate, the heart rate variability, the respiratory frequency and the masseter tone were monitored as biometrical parameters by the surgeons during the whole surgery for the quantification of mental demand. Stress situations could be identified during the procedures by an increase in the heart rate and a decrease in the heart rate variability. Stress level in procedures with navigation did not significantly differ from procedures without navigation. Interestingly, in 10 % of the cases a navigation system would have been helpful, although the surgeon stated before the procedure that such a system would not be necessary. Other stressors could be identified like time pressure, students or colleagues speaking with the surgeon or chatting in the OR and system failure of medical devices, i.e. navigation, sinus drill, electrocautery or shaver. Surgical stressors blurred vision due to diffuse bleeding and drill out procedures in the sphenoid sinus. Calming situations were a quiet atmosphere in the OR (i.e. closed doors) and the participation of another experienced colleague, especially a neurosurgeon. Stress situations occur when complex medical devices like the navigation do not work. For their proper function it is important that the whole OR-team is trained with it. Unqualified or unmotivated OR personnel create stress for the surgeon and disharmony in the team, which then ends in inadequate behaviour.

Immunolocalization of antimicrobial and cytoskeletal components in the serous glands of human sinonasal mucosa

Secretory cells in the seromucous glands of paranasal sinuses secrete antibacterial proteins for innate immune mucosal integrity. We studied the localization of antimicrobial and cytoskeletal components of the human seromucous glands and respiratory epithelium of the maxillary sinus and the ethmoidal cells by immunohistochemical methods. The presence of a variety of defense proteins such as lysozyme, lactoferrin, cathelicidin, and defensin-1, -2, -3 point to a crucial role in the immune defense for the respiratory tract. Cytoskeletal proteins such as actin, myosin 2, cytokeratin 7 and 19, α- and β-tubulin, investigated for the first time in glands of paranasal sinuses, showed a stronger expression at the apical and lateral cell membrane. The localization of the cytoskeletal proteins might point to their participation in exocrine secretory processes and stabilizing effects.

Characteristics of Distortion-Product Otoacoustic Emissions Level Decrease at High Altitude

Objective: 1) Understand the characteristics of Distortion-Product Otoacoustic Emissions (DPOAE) level decrease during ascent to high altitudes. 2) Learn whether DPOAE might provide information about the state of acclimatization and the risk of acute mountain sickness (AMS).

Method: From March 12, 2006, until April 23, 2006, DPOAE (f2 = 1, 1.5, 2, 3, and 4kHz), blood oxygen saturation (SaO2), and the Lake Louise score (LLS) to assess AMS were measured in 187 trekking tourists on the Mt Everest trek in Nepal at 2610 m and 5170 m.

Results: Mean DPOAE level decrease at 5170 m compared with 2610 m was -5.1dB (1kHz), -3.7dB (1.5kHz), -4.0dB (2kHz), -4.6dB (3kHz) and -3.7dB (4kHz). Mean SaO2 was 94.8% at 2610 m and 79.0% at 5170 m. The LLS indicates AMS when >2. While at 2610 m none of the study subjects had AMS (mean LLS 0.04), and at 5170 m 82 (43.9%) had AMS (mean LLS 2.8). Low SaO2 correlated with high LLS.

Conclusion: DPOAE levels decrease during ascent to high altitudes across all frequencies. This phenomenon might be due to cochlear hypoxia. While low SaO2 seems to indicate an increased risk of AMS, a decrease of DPOAE levels is not correlated with AMS.

Modeling the measurements of cochlear microcirculation and hearing function after loud noise

OBJECTIVE

Recent findings support the crucial role of microcirculatory disturbance and ischemia for hearing impairment especially after noise-induced hearing loss (NIHL). The aim of this study was to establish an animal model for in vivo analysis of cochlear microcirculation and hearing function after a loud noise to allow precise measurements of both parameters in vivo.

STUDY DESIGN

Randomized controlled trial. Setting. Animal study. Subjects and Methods. After assessment of normacusis (0 minutes) using evoked auditory brainstem responses (ABRs), noise (106-dB sound pressure level [SPL]) was applied to both ears in 6 guinea pigs for 30 minutes while unexposed animals served as controls. In vivo fluorescence microscopy of the stria vascularis capillaries was performed after surgical exposure of 1 cochlea. ABR measurements were derived from the contralateral ear.

RESULTS

After noise exposure, red blood cell velocity was reduced significantly by 24.3% (120 minutes) and further decreased to 44.5% at the end of the observation (210 minutes) in contrast to stable control measurements. Vessel diameters were not affected in both groups. A gradual decrease of segmental blood flow became significant (38.1%) after 150 minutes compared with controls. Hearing thresholds shifted significantly from 20.0 ± 5.5 dB SPL (0 minutes) to 32.5 ± 4.2 dB SPL (60 minutes) only in animals exposed to loud noise.

CONCLUSION

With regard to novel treatments targeting the stria vascularis in NIHL, this standardized model allows us to analyze in detail cochlear microcirculation and hearing function in vivo.

Frequency of bilateral cervical metastases in oropharyngeal squamous cell carcinoma: a retrospective analysis of 352 cases after bilateral neck dissection

BACKGROUND

The decision whether to perform an elective neck dissection in patients with head and neck squamous cell carcinoma (HNSCC) and clinically negative lymph nodes (cN0) is made based on the probability of micrometastases in the neck for the given subsite and size of the primary. To date there is limited information about contralateral and bilateral cervical lymph node metastases of oropharyngeal carcinoma.

METHODS

A retrospective chart review was performed of 352 patients with oropharyngeal SCC who received a bilateral neck dissection. The frequency of histologically unveiled bilateral neck metastases was determined.

RESULTS

Carcinomas of the tonsillar fossa starting with a T2 classification and carcinomas of the soft palate, base of tongue, and pharyngeal wall at any stage showed a high frequency of bilateral metastases.

CONCLUSIONS

Bilateral neck dissection should be recommended for all but T1 and selected cases of T2 carcinomas of the tonsillar fossa.

Does laryngopharyngeal reflux cause intraoral burning sensations? A preliminary study

Intraoral burning sensations are a common problem in the otolaryngological practice. The aim of this study was to evaluate if laryngopharyngeal reflux can cause intraoral burning sensations by measuring oropharyngeal acid reflux. Patients with recurring intraoral burning sensations underwent oropharyngeal pH monitoring in our outpatient clinic. The pH catheter was placed at the level of the uvula. The catheter contained an externally worn transmitter, which wirelessly sent the data to a monitor. In addition, patients were instructed to indicate meals or the occurrence of burning sensations by pressing provided buttons on the monitor. Corresponding events of burning sensations and a significant decrease in oropharyngeal pH values should be visualized. Twenty two patients suffering from recurring intraoral burning sensations underwent oropharyngeal pH measurement for 21-25 h. We could find oropharyngeal reflux episodes in 11 patients. However, we could not detect any episodes of burning sensations in the mouth corresponding with a decrease in oropharyngeal pH values. Our results suggest that there is no causal connection between LPR episodes and the occurrence of intraoral burning sensations in the examined patients. Although further studies with more patients are necessary in the future, we conclude from our findings that recurring intraoral burning sensations are not an indication for proton pump inhibitor therapy.

Simvastatin and Ginkgo biloba in the treatment of subacute tinnitus: a retrospective study of 94 patients

OBJECTIVES

Studies suggest that hypercholesterolemia promotes the development of inner ear disorders such as tinnitus. However, the underlying pathomechanisms are still not clearly defined.

METHODS

A retrospective study was performed to assess whether a reduction of serum cholesterol by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors may result in a relief of subacute tinnitus. Remission rates of 58 patients were investigated after 4 months of treatment with simvastatin (40 mg). Results were compared to treatment with Ginkgo biloba (120 mg; n = 36) as control group. Differences between tinnitus score at the day of first treatment and after 4 months were used as main outcome measure.

RESULTS

After treatment with simvastatin or G biloba, tinnitus score decreased from 41.3 ± 10.4 to 37.4 ± 17.3 and from 44.7 ± 11.2 to 41.2 ± 8.7, respectively. However, independently of the treatment regimen, differences of tinnitus scores were considered not significant.

CONCLUSIONS

After administration of simvastatin over 4 months, this retrospective study has shown no significant efficacy in treatment of subacute tinnitus. For a more conclusive answer, further prospective, double-blind, and placebo-controlled studies with a larger number of patients are needed.

Quantitative estimation of minor conductive hearing loss with distortion product otoacoustic emissions in the guinea pig

Subclinical conductive hearing losses (CHLs) can affect otoacoustic emissions and therefore limit their potential in the assessment of the cochlear function. Theoretical considerations to estimate a minor CHL from DPOAE measurements [Kummer et al. (2006). HNO 54, 457-467] are evaluated experimentally. They are based on the fact, that the level difference of the stimulus tones L(1) and L(2) for optimal excitation of the inner ear is given by L(1)=aL(2)+b. A CHL is presumed to attenuate both L(1) and L(2) to the same extent such that excitation of the inner ear is no longer optimal. From the change of L(1) that is necessary to restore optimal excitation of the inner ear and thus to produce maximal DPOAE levels, the CHL can be estimated. In 10 guinea pig ears an experimental CHL was produced, quantified by determination of compound action potential (CAP) thresholds at 8 kHz (CHL(CAP)) and estimated from DPOAE measurements at 8 kHz (CHL(DPOAE)). CHLs up to 12 dB could be assessed. CHL(DPOAE) correlated well with CHL(CAP) (R=0.741, p=0.0142). Mean difference between CHL(DPOAE) and CHL(CAP) was 4.2±2.6 dB. Estimation of minor CHL from DPOAE measurements might help to increase the diagnostic value of DPOAEs.

The influence of cholesterol on the motility of cochlear outer hair cells and the motor protein prestin

CONCLUSIONS

We provide evidence that cholesterol reduces electromotility in a dose-dependent matter. The data show that cholesterol modulates electromotility mainly by influencing the motor protein prestin, less by affecting the passive membrane properties.

OBJECTIVES

Elevated serum cholesterol is linked to inner ear disorders and may influence hearing by altering membrane properties of outer hair cells (OHCs) and by affecting the motor protein prestin. In this study we wanted to determine whether cholesterol modulates the electromotility of OHCs and if this modulation results from effects on the membrane properties or on the motor protein prestin.

MATERIALS AND METHODS

The motile responses of 12 isolated OHCs were investigated at increasing concentrations of 0, 0.1, and 1 mM extracellular cholesterol using the patch clamp technique and continuous video image analysis. To study effects on prestin, experiments were performed in 12 cells with half activated protein function and concentrations of 0 and 1 mM cholesterol.

RESULTS

Cholesterol at a concentration of 0.1 mM had no effect on motility. A concentration of 1 mM reduced maximal evoked shortening significantly by 29% in the depolarizing and by 9% in the hyperpolarizing direction. Investigating half activated motor proteins, 1 mM cholesterol reduced movements significantly by 18%, elongations decreased nonsignificantly by 5%.

An animal model for the analysis of cochlear blood flow [corrected] disturbance and hearing threshold in vivo

Impairment of cochlear blood flow (CBF) is considered to be important in inner ear pathology. However, direct measurement of CBF is difficult and has not been investigated in combination with hearing function. Six guinea pigs were used to show feasibility of an animal model for the analysis of cochlear microcirculation by intravital microscopy in combination with investigation of the hearing threshold by brainstem response audiometry (ABR). By the application of sodium nitroprusside (SNP), CBF was increased over 30 min. Reproducibility of measurements was shown by retest measurements. Mean baseline velocity of CBF was 109 +/- 19 mum/s. Vessel diameters had a mean value of 9.4 +/- 2.7 mum. Mean hearing threshold was 19 +/- 6 dB. In response to SNP, CBF velocity increased significantly to 161 +/- 26 mum/s. Mean arterial pressure decreased significantly to 36 +/- 11 mmHg. After the end of the application, CBF velocity recovered to a minimum of 123 +/- 17 microm/s. Within the retest, CBF velocity significantly increased to a maximum of 160 +/- 31 microm/s. Second recovery of CBF velocity was 125 +/- 14 mum/s. Within the second retest, CBF increased significantly to 157 +/- 25 microm/s. ABR thresholds did not change significantly. The increase in blood flow velocity occurred in spite of substantial hypotension as induced by a vasodilator. This may explain the fact that ABR threshold remained unchanged reflecting a maintained blood supply in this part of the brain. This technique can be used to evaluate effects of treatments aimed at cochlear microcirculation in inner ear pathologies.

[Otorhinolaryngological aspects of high altitude medicine]

The World Health Organisation estimates that about 40 million tourists every year climb to high (2,500-5,300 m) and extremely high altitudes (5,300-8,850 m). Thus altitude sickness and other health risks are increasing accordingly and so this fact requires clarification and advice for tourists in order to reduce the risks. That applies to the otolaryngologist, too. The non-traumatic health risks all result from the atmospheric conditions at high altitudes, in particular due to the lower atmospheric pressure. The partial pressure of oxygen (pO2), the temperature and the partial pressure of water vapour decrease continuously with increasing altitude and at the summit of the highest mountain on earth, Mt. Everest, the pO2 is reduced by two-thirds, from 212 to about 70 hPa. The temperature drops on average 6.5 degrees C per 1,000 m and at -20 degrees C 1 m3 of air contains at most just about 1 g of water vapour. The shortage of oxygen above 2500 m cannot be compensated for at once. Respiratory alcalosis, followed by hyperventilation, improves the alveolar loading of red blood cells (RBC) with oxygen, however, it also reduces the ventilatory drive from the central CO2-chemosensors as well from the peripheral O2-chemosensors located in the carotid bodies. Not until the alcalosis has been balanced by a renal secretion of bicarbonate, does the pO2-driven ventilatory stimulus normalize and the relative increase of RBC as a result of altitude diuresis improve and complete the acclimatisation. Up to an altitude of 4,000 m this adaptation takes several days to one week and up to 5,000 m up to 2 weeks. If acclimatisation has not taken place or has been insufficient, acute mountain sickness may develop. It is a harmless disorder, although it noticeably affects people physically and mentally and in some rare cases it might even develop into a life-threatening high-altitude edema in the brain or in the lung. Hematocrit values of up to 58 or even 60% at great altitudes are quite usual. Up to an altitude of 7,500 m the distortion product signals of the otoacustic emissions decrease not only between 1,000 and 1,500 Hz, but also between 3,000 and 4,000 Hz. The reduction of the inner ear signals, however, is reversible and disappears after descent. For the vestibular organ high altitudes do not mean a risk, either. 70% of all infections suffered by trekkers and climbers affect the upper airways. The cold, dry mountain air damages the mucociliary apparatus and thus leads a disposition towards acute recurrences in climbers suffering from chronic inflammations of the tonsils, the paranasal sinuses and the middle ear. In the oxygen-poor air these recurrences do not heal at all, or only very slowly, but also often tend to have a rather more complicated course.

Complex level alterations of the 2f (1)-f (2) distortion product due to hypoxia in the guinea pig

It is controversially discussed inasmuch acute hearing disorders might originate from impaired cochlear circulation. Hypoxia-specific alterations of inner ear parameters measurable in patients with acute sensorineural hearing loss would therefore be of great interest. Aim of this study was to characterize hypoxia-related alterations of the 2f (1)-f (2) distortion product. Nine guinea pigs were anaesthetized by i.m. administration of Midazolam, Medetomidin and Fentanyl. For introduction of hypoxia, the spontaneously breathing animals were offered a gas mixture of N(2)O and O(2) containing either 21 or 12-13% O(2). Distortion product otoacoustic emissions (DPOAEs) were continuously monitored at f (2) = 16 kHz; f (2)/f (1) = 1, 2; DP-definition = 2f (1)-f (2); L (1) = 65 dB and L (2) = 55 dB, while inhaled oxygen was switched from 21 to 12-13% and back. Oxygen saturation (SaO(2)) was continuously monitored. Data from an hypoxic interval were only used for further data processing if DPOAE levels were stable before and after hypoxia. Six hypoxic intervals in five animals fulfilled the stability criterion. During the hypoxic interval with the highest measured SaO(2) (75%), no alterations of DPOAE levels were observed. During the remaining five hypoxic intervals, when SaO(2) ranged between 57 and 70%, DPOAE levels were on average lower with an increased standard deviation compared to mean pre-hypoxic levels. Mean decrease correlated with the decrease of SaO(2 )(r = 0.90, P = 0.014). Alterations followed a characteristic time course-when hypoxia was started, DPOAE levels exhibited a short increase before they decreased and remarkably destabilized. After re-oxygenation DPOAE levels showed a pronounced level decrease, while SaO(2) already had recovered to pre-hypoxic values. After reaching a minimum, DPOAE levels slowly recovered to pre-hypoxic values. The decrease of DPOAE levels during hypoxia and the post-hypoxic level alterations have similarly been described by other authors before, while the distinct destabilization and transiently increased DPOAE levels have not been explicitly mentioned. A micromechanical mechanism that might explain a transient level increase and the post-hypoxic DPOAE level changes is discussed.

Subpixel tracking for the analysis of outer hair cell movements

CONCLUSION

Videomicroscopy with subpixel analysis is an excellent system for quantification of outer hair cell (OHC) movements. The resolution of a few nanometers is accurate enough to show induced differences of electromotility.

OBJECTIVE

Electromotility of OHCs is a voltage-dependent process resulting from a membrane protein named prestin. Voltage sensitivity is conferred to prestin by intracellular anions. Reduction of these anions reduces electromotility. Videomicroscopy and subpixel tracking combine video-based analysis with a resolution of few nanometers. The aim of this study was to show the feasibility of a system for quantification of OHC movements.

MATERIALS AND METHODS

Electromotility was investigated under normal and reduced intracellular chloride conditions. Cells were stimulated by the patch-clamp technique. Voltage steps were 500 ms long, ranging from -170 to +30 mV in 10 mV steps.

RESULTS

As in previous studies our results show the following. The direction of OHC movement depends on the polarity of voltage steps, length changes are not equal for symmetrical voltage steps of opposite polarity, average shortening for a depolarizing step (-70 mV to +30 mV) is about 13 nm/mV. Hyperpolarization (-70 mV to -170 mV) on average evokes elongations of about 3 nm/mV. Half maximal chloride concentration reduces motility by 14%; half maximal electromotility is reached by a 94% reduction of chloride.

WITHDRAWN: [Effects of atorvastatin on presbyacusis and tinnitus : A prospective, randomized, double-blind clinical trial.]

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Effect of atorvastatin on progression of sensorineural hearing loss and tinnitus in the elderly: results of a prospective, randomized, double-blind clinical trial

OBJECTIVE

To test whether the 3-hydroxy-3-methylglutaryl- coenzyme A reductase inhibitor atorvastatin can slow down the progression of presbycusis.

PATIENTS

Fifty patients 60- to 75-years-old with presbycusis and moderately elevated serum cholesterol.

INTERVENTION(S)

In a double-blind design, patients were randomly assigned to treatment with either atorvastatin (40 mg/d orally) or placebo.

MAIN OUTCOME MEASURE(S)

Pure-tone audiometry and tinnitus evaluation at enrolment and after 7 and 13 months.

RESULTS

Development of hearing thresholds after 7 and 13 months showed no significant differences between the groups. Tinnitus score continuously improved in the atorvastatin group (34.8 at 7 and 27.6 at 13 mo), whereas it slightly deteriorated in the placebo group (24.8 at 7 and 26.8 at 13 mo). The effect on tinnitus was a tendency without statistic significance (p = 0.0833).

CONCLUSION

Atorvastatin had no effect on the development of hearing thresholds, but resulted in a trend toward a relief of tinnitus.

Bilateral and unilateral internal carotid artery dissection causing isolated hypoglossal nerve palsy: a case report and review of the literature

Two cases of isolated hypoglossal nerve palsy due to internal carotid artery dissection are reported. In one case, a bilateral dissection was encountered. The clinical presentation and multidisciplinary management are discussed and the literature reviewed.

[The incidence of sudden hearing loss is greater than previously assumed]

The global incidence of sudden hearing loss is quoted to be 5-20 new cases/100,000 inhabitants/year. In the opinion of the present authors, the data on which these figures are based, are too old, methodologically questionable and non-transferable. An analysis of data from the compulsory health insurance carriers in Baden-Württemberg and the Nordrhein district suggests that an appreciably higher incidence must be assumed for Germany. Statistical processing of the numerical data of all cost carriers is necessary if we are to obtain an accurate incidence for Germany.

Photoirradiation therapy of experimental malignant glioma with 5-aminolevulinic acid

OBJECT

Accumulation of protoporphyrin IX (PPIX) in malignant gliomas is induced by 5-aminolevulinic acid (5-ALA). Because PPIX is a potent photosensitizer, the authors sought to discover whether its accumulation might be exploited for use in photoirradiation therapy of experimental brain tumors, without injuring normal or edematous brain.

METHODS

Thirty rats underwent craniotomy and were randomized to the following groups: 1) photoirradiation of cortex (200 J/cm2, 635-nm argon-dye laser); 2) photoirradiation of cortex (200 J/cm2) 6 hours after intravenous administration of 5-ALA (100 mg/kg body weight); 3) cortical cold injury for edema induction; 4) cortical cold injury with simultaneous administration of 5-ALA (100 mg/kg body weight) and photoirradiation of cortex (200 J/cm2) 6 hours later; or 5) irradiation of cortex (200 J/cm2) 6 hours after intravenous administration of Photofrin II (5 mg/kg body weight). Tumors were induced by cortical inoculation of C6 cells and 9 days later, magnetic resonance (MR) images were obtained. On Day 10, animals were given 5-ALA (100 mg/kg body weight) and their brains were irradiated (100 J/cm2) 3 or 6 hours later. Seventy-two hours after irradiation, the brains were removed for histological examination. Irradiation of brains after administration of 5-ALA resulted in superficial cortical damage, the effects of which were not different from those of the irradiation alone. Induction of cold injury in combination with 5-ALA and irradiation slightly increased the depth of damage. In the group that received irradiation after intravenous administration of Photofrin II the depth of damage inflicted was significantly greater. The extent of damage in response to 5-ALA and irradiation in brains harboring C6 tumors corresponded to the extent of tumor determined from pretreatment MR images.

CONCLUSIONS

Photoirradiation therapy in combination with 5-ALA appears to damage experimental brain tumors selectively, with negligible damage to normal or perifocal edematous tissue.