Effect of hypoglossal nerve stimulation on snoring: an evaluation using objective acoustic parameters.

STUDY OBJECTIVES: Hypoglossal nerve stimulation is an established therapy for sleep apnea syndrome. Whether or not this therapy on snoring and nighttime noise exposure is effective and how strong this effect may be has not been objectively investigated thus far and was the aim of this study. METHODS: In 15 participants (14 males; age: 30-72 years; mean: 51.7 years), polysomnography and acoustic measurements were performed before and after hypoglossal nerve stimulation. RESULTS: The therapy led to a significant improvement in sleep apnea (apnea-hypopnea index from 35.8 events/h to 11.2 events/h, P < .001). Acoustic parameters showed a highly significant reduction in the average sound pressure level (42.9 db[A] to 36.4 db[A], P < .001), averaged sound energy, A-weighted (LAeq; 33.1 db[A] to 28.7 db[A], P < .001), snoring index (1,068 to 506, P < .001), percentage snoring time (29.7-14.1%, P < .001), and psychoacoustic snore score, the latter being a measure of annoyance due to snoring (47.9 to 24.5, P < .001). CONCLUSIONS: This study was able to show for the first time by means of objective acoustic and psychoacoustic parameters that hypoglossal nerve stimulation can not only cause a significant improvement in sleep apnea but also has a positive effect on snoring and thus noise annoyance experienced by the bed partner. CLINICAL TRIAL REGISTRATION: Registry: German Clinical Trials Register; Name: Effect of Hypoglossal Nerve Stimulation on Snoring: An Evaluation Using Objective Acoustic Parameters; URL: https://drks.de/search/de/trial/DRKS00032354; Identifier: DRKS00032354. CITATION: Fischer R, Vielsmeier V, Kuehnel TS, et al. Effect of hypoglossal nerve stimulation on snoring: an evaluation using objective acoustic parameters. J Clin Sleep Med. 2024;20(3):363-370.

A standardized marking procedure for ENT operations to prevent wrong-site surgery: development, establishment and subsequent evaluation among patients and medical personnel.

PURPOSE: Wrong-site surgeries are rare but potentially serious clinical errors. Marking the surgical site is crucial to preventing errors, but is hindered in the ENT field by the presence of many internal organs. In addition, there is no standardized marking procedure. METHODS: Here, an ENT surgical-marking procedure was developed and introduced at a clinic. The procedure was evaluated through anonymized questionnaires. This study was conducted over a 6-month period by interviewing patients and, at the beginning and end of this period, doctors and other surgical staff. RESULTS: The internal organ-marking problem was solved by applying a fixed abbreviation for each procedure onto the shoulder in addition to marking the skin surface as close to the organ as possible. The procedure was described as practicable by 100% of the interviewees; 75% of the ENT physicians and 96.3% of the other surgical staff considered the procedure highly important for preventing site confusion, and 75% of the physicians had a consequently greater feeling of safety. Of the 248 patients surveyed, 96.0% considered the marking procedure useful, and 75.8% had a consequently greater feeling of safety. For 52.0%, the marking reduced their fear of the operation. CONCLUSIONS: For the first time, a standardized procedure was developed to mark the site of ENT surgery directly, uniformly and safely on patients. The procedure was judged to be useful and practicable and was also deemed crucial for preventing site confusion. Patients felt safer and less fearful of the operation due to the marking.

Tobacco use in patients with ENT tumours: Deficits in the provision of education and smoking cessation support.

PURPOSE: Smoking is not only one of the main risk factors for the development of most malignant and numerous benign ENT tumours but also has an important influence on therapy and prognosis. Even quitting smoking at the time of diagnosis significantly reduces mortality. Patients have a particularly strong desire to stop smoking when they are diagnosed. The present study investigated to what extent patients were aware of the relationships between smoking and the development and prognosis of tumours and how much information and smoking cessation support they were offered by physicians. METHODS: A total of 194 patients (74.7% male, 62.0 ±10.6 a) with malignant primary ENT tumours, pre-cancerous tumours, Reinke's oedema and salivary gland tumours were interviewed. RESULTS: 22.7% were nonsmokers, 49.5% were cigarette smokers and 27.8% were ex-smokers. A total of 57.0% of the smokers said they would have quit before the onset of the disease if they had known about the association. Forty-one percent did not receive information about the association between smoking and the development of their disease, while 45.5% did not receive information about the relationship with their prognosis. The provision of information lasted less than 5 min for 40.4% of the patients and more than 10 min for only 13.5%. In total, 50.7% of the patients were directly requested not to smoke. A total of 7.7% received offers of smoking cessation support from otolaryngologists and 18.2% received such offers from family physicians. CONCLUSIONS: There is a pronounced need for improvements in the provision of medical information about the health risks associated with smoking and offers to support patient efforts to stop smoking. In particular, the appointment during which the diagnosis is communicated to the patient should be considered a 'teachable moment' that can lead to smoking cessation.

[Hygiene in ENT examination: Fluorescence study with overview of current recommendations]. / Hygiene bei der HNO-Untersuchung: Fluoreszenzstudie mit Übersicht der aktuellen Empfehlungen.

Increasing normative demands on patient safety and quality assurance measures, but also the problem of multi-resistant germs and pathogens with a high potential for infection, increase the need for hygienically correct work.In this study, hygienically relevant potential sources of contamination in ENT examinations were to be identified and possible improvement strategies examined.A complete ENT examination was performed by 5 examiners with different professional experience, whose gloves were wetted with fluorescent lotion prior to the examination. Contaminations especially on the examination unit and on the instruments were identified. The potential risk of transmission of pathogens to subsequent patients was assessed using a specially developed score. Various strategies to reduce identified contamination possibilities were developed and thought through.The score of the investigators was very high with an average of 87.4 points (±3.6). The implementation of individual hygiene measures during the examination process would lead to a significant reduction of the score and thus to an improvement in hygiene: No shaking of hands (81.8), additional disinfection of patient's chair (79.8), disinfection of important surfaces (69.8), provision of standard instruments (60.2) or all instruments (32.2), disinfection of all relevant surfaces and provision of all instruments (7.4).The results show very clearly that an ENT examination is a complex procedure from the point of view of hygiene. For reliable protection against possible transmission events, a structured bundling of hygiene measures is therefore necessary.

Are annoyance scores based on sound pressure levels suitable for snoring assessment in the home environment?

PURPOSE: An objective statement about the annoyance of snoring can be made with the Psychoacoustic Snore Score (PSS). The PSS was developed based on subjective assessments and is strongly influenced by observed sound pressure levels. Robustness against day-to-day interfering noises is a fundamental requirement for use at home. This study investigated whether or not the PSS is suitable for use in the home environment. METHODS: Thirty-six interfering noises, which commonly occur at night, were played in the acoustic laboratory in parallel with 5 snoring sounds. The interfering noises were each presented at sound pressure levels ranging from 25 to 55 dB(A), resulting in 3255 distinct recordings. Annoyance was then assessed using the PSS. RESULTS: In the case of minimally annoying snoring sounds, interfering noises with a sound pressure level of 25 dB(A) caused significant PSS changes from 40 to 55 dB(A) for annoying snoring sounds. If the interfering noise was another snoring sound, the PSS was more robust depending on the sound pressure level of the interfering noise up to 10 dB(A). Steady (no-peak) interfering noises influenced the PSS more strongly than peak noises. CONCLUSIONS: The PSS is significantly distorted by quiet interfering noises. Its meaningfulness therefore depends strongly on the acoustic environment. It may therefore be assumed that scores dependent on sound pressure level are suitable for measurements when there is minimal ambient noise, as in the sleep laboratory. However, for measurements where noise is incalculable, as in the home environment, interfering noises may distort the results.

Snoring: is a reliable assessment possible?

PURPOSE: It is not easy to assess how severe and annoying a patient's snoring is. Solid parameters are lacking; snorers cannot deliver a reliable self-assessment and it is uncertain whether bed partners' statements can be relied upon. The purpose of the present study was therefore to investigate whether and how well snoring assessment based on acoustic parameters and bed partners' reporting agree. METHODS: In a double-blind, placebo-controlled study on snoring treatment, several acoustic parameters [snoring index (SI), percentage snoring time (ST), sound pressure level, sound energy, loudness, psychoacoustic annoyance and psychoacoustic snore score (PSS)] were measured in 18 subjects during 24 polysomnographies. Bed partners also assessed snoring annoyance and loudness as well as treatment outcome. RESULTS: No correlation was found between the subjective annoyance caused by snoring and the acoustic parameters. Regarding perceived loudness, there was a moderate, significant correlation with loudness (N5) and PSS over the hour with the highest SI. SI, ST, LAeq and maximum sound pressure level dB(A)max showed no significant correlation. After the intervention only mean sound energy LAeq over the entire night showed a significant correlation (rs = 0.782; p = 0.022) with bed partners' assessments. However, this result was not confirmed in the second control night. CONCLUSIONS: The non-existent or only weak correlation between bed partners' ratings and objective parameters indicate that snoring severity should be evaluated with caution. Neither acoustic parameters, at least for one measurement over just one night, nor bed partners' ratings should be used as the sole basis for snoring assessment.

Snoring - An Acoustic Definition.

Objective- The distinction of snoring and loud breathing is often subjective and lies in the ear of the beholder. The aim of this study is to identify and assess acoustic features with a high suitability to distinguish these two classes of sound, in order to facilitate an objective definition of snoring based on acoustic parameters. Methods- A corpus of snore and breath sounds from 23 subjects has been used that were classified by 25 human raters. Using the openSMILE feature extractor, 6 373 acoustic features have been evaluated for their selectivity comparing SVM classification, logistic regression, and the recall of each single feature. Results- Most selective single features were several statistical functionals of the first and second mel frequency spectrum-generated perceptual linear predictive (PLP) cepstral coefficient with an unweighted average recall (UAR) of up to 93.8%. The best performing feature sets were low level descriptors (LLDs), derivatives and statistical functionals based on fast Fourier transformation (FFT), with a UAR of 93.0%, and on the summed mel frequency spectrum-generated PLP cepstral coefficients, with a UAR of 92.2% using SVM classification. Compared to SVM classification, logistic regression did not show considerable differences in classification performance. Conclusion- It could be shown that snoring and loud breathing can be distinguished by robust acoustic features. The findings might serve as a guidance to find a consensus for an objective definition of snoring compared to loud breathing.

Calculating annoyance: an option to proof efficacy in ENT treatment of snoring?

To develop and validate an objective method for calculating the annoyance caused by snoring sounds. 53 subjects assessed 50 different snoring and breath sounds on a visual analog scale for level of annoyance. A linear regression analysis was used to correlate these subjective assessments with objectively calculated psychoacoustic parameters (loudness, roughness, sharpness, and fluctuation strength, calculating the maximum, mean, and 5th percentile in each case). The quality of the resulting formula was checked, and additional validation was performed using subjective assessments of 60 new snoring and breath sounds by 52 new subjects. Receiver operating characteristic (ROC) analysis was used to scale the annoyance ranges obtained with the formula. A score consisting of the 5th percentile of loudness and the mean of roughness was developed. The formula displays high goodness of fit (R 2 = 0.91) and quality. In the validation phase, a highly significant correlation (r s = 0.95; p < 0.01) was obtained between the scores calculated with the formula and the subjective assessments. ROC analysis was able to define the annoyance ranges with a discriminatory power between 52 and 73 % (optimum sensitivity/specificity). The subjective assessments made by the participants were distinctly scaled and were reflected in a psychophysical algorithm. In the setting of polygraphy and polysomnography, this means that a reliable annoyance score that is not dependent on the bed partner can be obtained to establish the indication for anti-snoring treatments and to review their utility.

Depth-dependent changes of obstruction patterns under increasing sedation during drug-induced sedation endoscopy: results of a German monocentric clinical trial.

PURPOSE: Drug-induced sedation endoscopy (DISE) and simulated snoring (SimS) can locate the site of obstruction in patients with sleep-disordered breathing (SDB). There is clinical evidence for a change in collapsibility of the upper airway depending on the depth of sedation. So far, a dose-response relationship between sedation and collapsibility has not been demonstrated. METHODS: DISE and SimS were performed in 60 consecutive patients with SDB under monitoring of depth of sedation by BiSpectral Index® (BIS). Initially, SimS was conducted followed by DISE using bolus application of propofol. Sedation was performed up to a sedation level representing slow wave sleep (BIS = 40). The collapsibility of the upper airway was documented at decreasing sedation levels by an identical pictogram classification. RESULTS: For all levels and patterns of obstruction, a dose-dependent increase in the collapsibility of the upper airway was detected. A maximum collapsibility was achieved at sedation levels representing slow wave sleep. The collapsibility during SimS corresponded to light sleep stages and did not cover slow wave sleep. CONCLUSION: A dose-dependent change of patterns of obstructions can be observed during DISE under BIS monitoring indicating sedation depth. The obtained patterns of obstruction during DISE and SimS should thus be interpreted with regard to the sedation depth.

Positive frozen section margins predict local recurrence in R0-resected squamous cell carcinoma of the head and neck.

OBJECTIVES: The purpose of this study was to analyse the impact of surgical margins on tumour recurrence and survival of patients with carcinomas of the head and neck. MATERIAL AND METHODS: A cohort of 156 patients with primary squamous cell carcinoma of the head and neck treated by local resection with negative margins and neck dissection between 2004 and 2012 was investigated. Margin status in frozen sections and permanent paraffin tissues were analysed and compared to clinical and histopathological parameters as well as to tumour recurrence (local, regional and distant) and disease-specific survival (DSS). RESULTS: Close margins (<5mm) on permanent sections were correlated to high-grade differentiation (p=0.070), lymphangiosis (p=0.009) and positive neck nodes (p=0.025) implicating regional and distant recurrence (p=0.001) as well as unfavorable DSS (p=0.002). Positive margins on initial frozen section analysis revised into negative margins during further surgery were the strongest predictor for local recurrence in uni- and multivariate analysis (p<0.001, hazard ratio 3.34). However, positive frozen section margins were not significantly predictive for DSS (p=0.150). Significant predictors for DSS in univariate analysis were local recurrence (p=0.026), T-stage (p=0.02), N-stage (p<0.001), grading (p=0.02) and lymphangiosis (p=0.001). Multivariate DSS analysis revealed lymph node metastasis (p=0.005) and local recurrence (p=0.017) as significant negative predictors. CONCLUSION: Close margins on permanent sections are associated with aggressive tumour characteristics, regional and distant metastasis implicating worse DSS. The accuracy of frozen section analysis seems limited as positive frozen section margins revised into negative margins bear a high risk of local recurrence.

Genomic aberrations of MDM2, MDM4, FGFR1 and FGFR3 are associated with poor outcome in patients with salivary gland cancer.

Fibroblast growth factor receptor 1 and 3 (FGFR1, FGFR3) impact on tissue homoeostasis, embryonic development and carcinogenesis. Murine double minute protein 4 (MDM4) and mouse double minute 2 homologue (MDM2) are regulators of p53-protein and may be the origin of an apoptosis overpowering cascade. A collective of 266 carcinomas of salivary glands were investigated for MDM2, MDM4, FGFR1 and FGFR3 aberrations by fluorescence in situ hybridization (FISH). The results were matched with clinicopathological parameters and with expression of PTEN and p53. MDM2 gene amplification (n = 9) and chromosomal aberrations (trisomy, n = 47; high polysomy, n = 7) are linked to high-grade malignancy (P < 0.001), lymph node metastasis (P = 0.001), advanced tumour size (P = 0.013) and stage (P < 0.001), gender (P = 0.002) and age (P = 0.001). MDM4 gene amplification (n = 19) and chromosomal aberrations (trisomy, n = 34; high polysomy, n = 31) are correlated to high-grade malignancy (P < 0.001), lymph node metastasis (P = 0.008), advanced tumour size (P = 0.039), stage (P = 0.004) and loss of PTEN (P < 0.001). Only, high-grade malignancy (P < 0.001), lymph node metastasis (P = 0.036) and advanced tumour stage (P = 0.025) are associated with FGFR3 amplification (n = 1) or chromosomal aberrations (low polysomy, n = 61; high polysomy, n = 55) but not with MDM4 alterations. FGFR1 amplifications (n = 5) and chromosomal aberrations (trisomy, n = 38; high polysomy, n = 30) are associated with high-grade malignancy (P < 0.001), advanced tumour size (P = 0.026) and stage (P = 0.004), gender (P = 0.016) and age (P = 0.023). Aberrations of MDM2, MDM4, FGFR1 and FGFR3 correlate with aggressive tumour growth and nodal metastasis. MDM2 (P < 0.001), MDM4 (P = 0.005) and FGFR3 (P = 0.006) alterations are associated with worse overall survival of patients with salivary gland cancer.

Drug-induced sleep endoscopy and simulated snoring in patients with sleep-disordered breathing: agreement of anatomic changes in the upper airway.

Drug-induced sleep endoscopy (DISE) and simulated snoring (SimS) are performed as part of the diagnostic procedure in patients with suspected sleep-disordered breathing (SDB). Despite both techniques frequently performed, they have rarely been evaluated yet in terms of agreement of the obtained results. Both diagnostic procedures were performed consecutively in 40 patients with SDB and documented identically. The obtained data were analysed with respect to the agreement of both procedure at different levels of the oropharynx as well as different patterns of obstruction and vibration. The anterior-posterior collapsibility of the soft palate/uvula revealed a moderate agreement between SimS and DISE (κ = 0.42; 95 % CI 0.22-0.63). The dorsal shift of the tongue base agreed moderate for patients with an AHI below 10 (κ = 0.47) and above 25 (κ = 0.44) between SimS ad DISE. The lateral and circular pharyngeal collapsibility at velum and tongue base level did not agree between SimS and DISE, was higher for DISE and could be partially reversed by mandibular protrusion. Collapse patterns of the soft palate and uvula can be induced by SimS and resemble the patterns induced by DISE. The dorsalization of the tongue base can be simulated to a lower extent by SimS. Lateral and circular patterns of collapse at the upper and lower oropharynx induced by DISE do not seem to be simulated by SimS. SimS seems to be an additional method to screen the collapsibility of the soft palate and uvula prior to DISE.

Are subjective assessments of snoring sounds reliable?

The aim of this study is to investigate whether snoring sounds can be reliably, i.e. reproducibly and comparably, assessed by the listener. This is an absolute prerequisite if an objective method is to provide a valid representation of subjective assessments of snoring sounds. Fifty-three subjects, both men and women, from different age categories assessed snoring sequences in terms of their annoyance level. This was done using a paired comparison model with ten sequences, once at original volume and once at adjusted peak level. In addition, assessments of 50 sequences were made using a visual analog scale (VAS). In the first paired comparison the assessments displayed very high consistency (K = 0.94) and high concordance (W = 0.83). The results showed very good agreement between the sexes (r s = 0.98), between different levels of snoring-related experience (r s = 0.99) and between different ages (r s = 0.98). At adjusted peak level there was also very high consistency (K = 0.91) although concordance was clearly lower (W = 0.50). The rankings in the two paired comparisons showed a high degree of correlation (r s = 0.81). The assessments on the VAS revealed good inter-rater reliability (α = 0.73) and a high degree of correlation with the result of the first paired comparison (r s = 0.93). Snoring sounds can be assessed in a reproducible and comparable manner in terms of their annoyance level. There are no gender-specific differences, and age-specific and experience-specific differences also appear to be negligible. While volume plays a dominant role, other characteristics of the sounds are also sufficient to permit an assessment.

Long-term outcome and subjective quality of life after surgical treatment of lower lip cancer.

OBJECTIVES: Squamous cell carcinoma of the lower lip represents a common type of cancer with a favourable prognosis. Different types of defect reconstruction after ablative surgery are described for maintenance of patients' quality of life. MATERIALS AND METHODS: The study retrospectively evaluates the outcome of 105 patients treated for lower lip cancer. Oncological data as well as individual quality of life were investigated. RESULTS: Cervical lymph node metastases rarely occurred (7.6 %) and were correlated to larger-sized tumours (p = 0.041). Only five patients (4.8) died related to the tumour disease, especially after lymph node metastasis and tumour recurrence (p < 0.001). The 5-year rates for recurrence-free, overall and disease-specific survival were 84.5, 61.2 and 93.9 %. Tumour recurrence correlated with a resection margin of less than 0.75 cm (p = 0.089). With view to postoperative quality of life, the modified Bernard-Fries technique showed the most unfavourable results, particularly referring to sensibility, paraesthesia, lip pursing and mouth opening compared to a stair-step and/or Abbe reconstructions. CONCLUSIONS: Squamous cell carcinoma of the lower lip shows a very favourable prognosis. Neck dissection seems often negligible particularly in small tumours. Patients' functional quality of life after lip surgery depends on the size of the primary and the used technique. Stair-step and/or Abbe reconstructions should be preferred to a Bernard-Fries technique in comparable defect sizes. CLINICAL RELEVANCE: Proper treatment of lower lip cancer provides favourable prognosis and preserves patients' functional and aesthetic quality of life.

Evaluation of acoustic characteristics of snoring sounds obtained during drug-induced sleep endoscopy.

INTRODUCTION: Snoring sounds are discussed to contain acoustic information about their geneses. Nocturnal snoring can easily be recorded acoustically but it is difficult to visually verify its genesis. Contrary, snoring patterns induced by drug-induced sleep endoscopy (DISE) can be visually differentiated. The aim of the study was to classify patterns of obstructions and vibration during DISE and to evaluate acoustic characteristics between these different patterns of snoring. METHODS: DISE was performed in 41 male patients with sleep-disordered breathing. The recorded video sequences (n = 108) were classified visually at a mute mode in different patterns of snoring (velar, velar obstructive, tonsillar, post-apnoeic). The sound tracks of these subgroups were analysed and compared with regard to the parameters sound pressure level, loudness, sharpness, roughness, fluctuations strength and centre frequency. RESULTS: Obstructive snoring patterns revealed a higher loudness than non-obstructive patterns (>25 sone). Velar snoring showed more roughness (>150 cAsper) than tonsillar and post-apnoeic snoring and revealed the lowest centre frequency (<3000 Hz) of all patterns. Tonsillar snoring presented the highest sharpness (>1.6 acum) whereas post-apnoeic snoring revealed the largest fluctuation strength (>50 cVacil). CONCLUSION: Different snoring patterns induced by DISE can be classified visually, and an approach to differentiate them acoustically by means of psychoacoustic analyses is demonstrated. On the basis of these results, nocturnal snoring might also be differentiated by psychoacoustic algorithms which could be implemented in acoustic polygraphic screening devices in the future.

Predictors of cervical lymph node metastasis in salivary gland cancer.

BACKGROUND: This study compares clinicopathological parameters with novel molecular markers for predicting cervical lymph node metastasis in salivary gland cancer. METHODS: Three hundred sixteen salivary gland carcinomas were included in this study. Genomic epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), phosphatase and tensin homolog (PTEN), and hepatocyte growth factor receptor (MET) was determined by fluorescence in situ hybridization (FISH). Chi-square tests, multivariate regression, and Kaplan-Meier survival analysis were used for statistics. RESULTS: Nodal staging determines long-term survival. Clinicopathological parameters associated with positive neck nodes are advanced age (p = .006), T3/T4 classification, histological high-grade malignancy, and diagnosis of salivary duct carcinoma (p < .001 each). Neck node metastases also correlate with copy number gain of EGFR (p = .004) and HER2, aberration of MET, and deletion of PTEN (p < .001 each). Multivariate analysis showed SDC (p = .002) to be the strongest predictor of lymph node metastasis, followed by MET aberration (p = .009), T3/T4 classification (p = .017), PTEN deletion (p = .042), and adenocarcinoma not otherwise specified (NOS; p = .047). CONCLUSION: The histological subtype is crucial for decisions regarding neck dissection. New molecular parameters may also indicate elective treatment of the neck.

Distinguishing snoring sounds from breath sounds: a straightforward matter?

BACKGROUND: Although snoring is a common problem, no unequivocal definition yet exists for this acoustic phenomenon. The primary study objective was to investigate whether snoring sounds can be distinguished at all clearly from breath sounds. Our secondary objective was to evaluate whether the sound pressure level in common use and psychoacoustic parameters are suitable for making this distinction. METHODS: Twenty-five subjects exposed to 55 sound sequences were asked to decide whether these were breath sounds or snoring sounds, and to indicate how certain they were about their decision. The sound pressure level and the psychoacoustic parameters of loudness, sharpness, roughness, and fluctuation strength were then analyzed, and psychoacoustic annoyance was calculated from these parameters. RESULTS: Sixteen percent of the sound sequences could not be classified unequivocally, although the individual raters stated that they were still moderately certain about their decision. The sound pressure level and psychoacoustic parameters were capable of distinguishing between breath sounds and snoring sounds. The optimum for sensitivity and specificity was 76.9 and 78.8 %, respectively. CONCLUSIONS: Because snoring appears to be a subjective impression, at least in part, a generally valid acoustic definition therefore seems to be impossible. The sound pressure level and psychoacoustic parameters are suitable for distinguishing between breath sounds and snoring sounds. Nevertheless, when interpreting results, the only moderate validity of these parameters due to the absence of a universally valid definition of snoring should be taken into account.

The nasal cycle during wakefulness and sleep and its relation to body position.

OBJECTIVES/HYPOTHESIS: To compare the occurrence, duration, and relative amplitudes of the nasal cycle (NC) during wakefulness and sleep, and to investigate the relationship of the NC to body position. STUDY DESIGN/METHODS: In 20 healthy subjects, the NC was measured by long-term rhinoflowmetry for an average 23.1 hours during wakefulness and sleep. Head and body position were also recorded during the night. RESULTS: A classic NC was displayed by 50% of subjects during wakefulness and by 75% of the subjects during sleep. Cycle duration during wakefulness was 91.1 minutes (± 65.2; 20-337), increasing significantly during sleep to 178 minutes (± 92.8; 21-498) (P < 0.01). The relative mean flow of the working phase during wakefulness was 67.6% (± 8.0; 58-90), and it was significantly higher during sleep at 82.0% (± 6.8; 63-93) (P < 0.01). On recumbency, there was a significant correlation between body position and resting phase side (r = 0.67; P = 0.024). To a significant extent, positional shifts led to subsequent NC laterality changes (22%; P < 0.01). Conversely, to a significant extent, positional shifts preceded NC laterality changes (57.6%; P < 0.01). Body position changed in a nonsignificant number of cases (30.3%; P = 0.16) due to reversal of the congestion side of the inferior turbinates. CONCLUSION: The results of our study show that the NC during sleep is characterized by longer cycle durations and greater amplitudes than during wakefulness on normal physical activity. Shifts in body position during sleep alter the NC in a specific direction to a significant extent, but the opposite is not the case. LEVEL OF EVIDENCE: 4.

Value of anatomic site, histology and clinicopathological parameters for prediction of lymph node metastasis and overall survival in head and neck melanomas.

INTRODUCTION: Head and neck melanoma compromises a group of aggressive tumours with varying clinical courses. This analysis was performed to find anatomic and clinicopathological parameters predictive for lymph node metastasis and overall survival. MATERIAL AND METHODS: Data and outcome of 246 patients with a malignant melanoma in the head and neck region were retrospectively analyzed for predictive parameters. RESULTS: Lentigo maligna melanoma (n = 115) was the most frequent histology, followed by superficial spreading (n = 63) and nodular melanoma (n = 52). More than half of the melanomas (n = 138) were in the face. Tumours of the face and anterior scalp metastasized to lymph nodes of the neck and parotid gland, whereas tumours of the posterior scalp and neck also metastasized to the nuchal region. Advanced Clark level, presence of tumour ulceration and younger age were the strongest predictors of lymph node metastasis in multivariate regression analysis (p < 0.05), but anatomic site, histological subtype and tumour thickness were also associated with lymph node metastasis. Lymph node metastases, distant metastases, ulceration, nodular subtype and non-facial site of origin were the strongest negative prognostic parameters for disease-specific overall survival (p < 0.05). In contrast, the width of resection margin (<1 cm vs. 1-2 cm vs. >2 cm) did not correlate with tumour recurrence and overall survival (p > 0.05). CONCLUSION: Histological subtype diagnosis, anatomic site of origin as well as the established factors tumour thickness, ulceration and depth of invasion are prognostic indicators of cervical lymph node metastasis and overall survival. A resection margin of at least 1 cm seems sufficient in head and neck melanoma. The status of sentinel lymph node biopsy and neck dissection has to be proven within the next years.

Triple test as predictive screen for unilateral weakness on caloric testing in routine practice.

OBJECTIVE: To investigate in vertigo patients in routine practice to what extent a rapid and straightforward triple bedside test (spontaneous nystagmus, head-shaking nystagmus, and the head impulse test) can predict a normal result on caloric testing. STUDY DESIGN: Prospective, single-blind, diagnostic study. SETTING: Tertiary referral center. PATIENTS: 151 patients (78 male and 73 female subjects; mean age, 52.5 +/- 16.4 yr) presenting with acute or recent symptoms of vertigo. INTERVENTION: Diagnostic evaluation. MAIN OUTCOME MEASURE: The negative predictive value (NPV) of the triple test in relation to a normal caloric test response. RESULTS: In unilateral weakness (UW) on caloric testing (UW, >=25%), the triple test had sensitivity of 63.6%, specificity of 85.4%, a positive predictive value (PPV) of 71.4%, and an NPV of 80.4%. In other words, 80.4% of patients with a negative triple test also had a normal response on caloric testing. In pronounced canal paresis (UW, >=50%), the triple test had sensitivity of 81.8%, specificity of 81.4%, a PPV of 55.1%, and an NPV of 94.1%. Significant differences were found between 2 subgroups assessed by examiners with differing levels of experience (p < 0.05). CONCLUSION: The triple test represents a good screening tool that quickly and reliably excludes unilateral weakness and in particular pronounced canal paresis on caloric testing.