A multiscale product approach for an automatic classification of voice disorders from endoscopic high-speed videos

Direct observation of vocal fold vibration is indispensable for a clinical diagnosis of voice disorders. Among current imaging techniques, high-speed videoendoscopy constitutes a state-of-the-art method capturing several thousand frames per second of the vocal folds during phonation. Recently, a method for extracting descriptive features from phonovibrograms, a two-dimensional image containing the spatio-temporal pattern of vocal fold dynamics, was presented. The derived features are closely related to a clinically established protocol for functional assessment of pathologic voices. The discriminative power of these features for different pathologic findings and configurations has not been assessed yet. In the current study, a collective of 220 subjects is considered for two- and multi-class problems of healthy and pathologic findings. The performance of the proposed feature set is compared to conventional feature reduction routines and was found to clearly outperform these. As such, the proposed procedure shows great potential for diagnostical issues of vocal fold disorders.

[First experience in the thyroid and parathyroid surgery using the da Vinci® system]

BACKGROUND

Endoscopic surgery for the treatment of thyroid and parathyroid pathologies is gaining increasing attention. The da Vinci® system has been already widely used in different fields of medicine including recently thyroid and parathyroid surgery. Herein we report our first experiences in endoscopic surgery of thyroid and parathyroid pathologies using the da Vinci® system.

MATERIAL AND METHODS

8 patients presenting with struma nodosa in 6 cases and parathyroid adenomas in 2 cases have been treated using the da Vinci® system at the ENT department of Homburg/Saar University.

RESULTS

The skin incision to introduce the instruments with the da Vinci® system were axilar or at the lateral segment of the clavicle. The neurovascular structures like inferior laryngeal nerve as well as the pathologies were clearly 3-dimensional visualized in all 8 cases. No paralysis of the vocal cord was observed. All patients had in histological examination a benign pathology.

CONCLUSIONS

The endoscopic surgery of the thyroid and parathyroid gland can be performed using the da Vinci® system and offers an excellent, intraoperative, 3-dimensional visualization of the neurovascular structures. Additionally the da Vinci® system enables skin incisions within considerable distance from the thyroid and parathyroid gland.

[Complications and pitfalls in surgery of the ear/lateral skull base]

Surgery of the ear and the lateral skull base is a fascinating, yet challenging field in otorhinolaryngology. A thorough knowledge of the associated complications and pitfalls is indispensable for the surgeon, not only to provide the best possible care to his patients, but also to further improve his surgical skills.Following a summary about general aspects in pre-, intra- and postoperative care of patients with disorders of the ear/lateral skull base, this article covers the most common pitfalls and complications in stapes surgery, cochlear implantation, surgery of vestibular schwannomas, and jugulotympanal paragangliomas. Based on these exemplary procedures, basic "do's and don'ts" of skull base surgery are explained, which the reader can easily transfer to other disorders. Special emphasis is laid on functional aspects, such as hearing, balance and facial nerve function. Furthermore, the topics of infection, bleeding, skull base defects, quality of life and indication for revision surgery are discussed.An open communication about complications and pitfalls in ear/lateral skull base surgery among surgeons is a prerequisite for the further advancement of this fascinating field in ENT surgery. This article is meant to be a contribution to this process.

Mini-endoscopy of the frontal sinus to guide endonasal frontal sinus surgery

Endoscopic frontal sinus surgery requires special attention to the numerous anatomical variations. Additionally, in situations of revision surgery, endonasal frontal sinus identification may be challenging. Numerous strategies have been described to access the frontal sinus in endonasal endoscopic frontal sinus surgery including an additional external approach. A pilot study is presented using a newly designed modular mini-endoscope (1.1 mm, 10.000 pixel, 2 working channels and 120° lens) to assist the frontal sinus surgery through a transcutaneous puncture of the frontal sinus. We used this mini-endoscope for primary frontal sinus surgery on 3 patients and for revision frontal sinus surgery on 4 patients. In all patients, the mini-endoscope could be placed in the frontal sinus without side effects. The visible illumination at the frontal sinus floor, caused by the mini-endoscope being in the frontal sinus, guided the surgeon endonasally directly to the frontal sinus floor. Frontal sinus drainage was achieved by the described guidance on all patients. In conclusion, mini-endoscopy of the frontal sinus might be an interesting option in endoscopic frontal sinus surgery to guide the surgeon by illumination in complex anatomical situations to the frontal sinus. This technique will contribute to further improvement in endonasal endoscopic frontal sinus surgery.

Electromotive Triggering and Single Sweep Analysis of Vestibular Evoked Myogenic Potentials (VEMPs)

Cervical (c) and ocular (o) vestibular evoked myogenic potentials (VEMPs) provide important tools for measuring otolith function. However, two major drawbacks of this method are encountered in clinical practice. First, recording of oVEMPs is compromised by small n10 amplitudes. Second, VEMP analysis is currently based on the averaging technique, resulting in a loss of information compared to single sweep analysis. Here, we: 1) developed a novel electromotive trigger mechanism for evoking VEMPs by bone-conducted vibration to the forehead and 2) established maximum entropy extraction of complex wavelet transforms for calculation of phase synchronization between VEMP single sweeps. Both c- and oVEMPs were recorded for n=10 healthy individuals. The oVEMP n10 amplitude was consistently higher (right: 24.84±9.71 μV; left: 27.40±14.55 μV) than previously described. Stable VEMP signals were reached after a smaller number of head taps (oVEMPs 6; cVEMPs 11) compared to current recommendations. Phase synchronization vectors and phase shift values were successfully determined for simulated and clinically recorded VEMPs, providing information about the impact of noise and phase jitter on the VEMP signal. Thus, the proposed method constitutes an easy-to-use approach for the fast detection and analysis of VEMPs in clinical practice.

A wavelet-based approach for a continuous analysis of phonovibrograms

Recently, endoscopic high-speed laryngoscopy has been established for commercial use and constitutes a state-of-the-art technique to examine vocal fold dynamics. Despite overcoming many limitations of commonly applied stroboscopy it has not gained widespread clinical application, yet. A major drawback is a missing methodology of extracting valuable features to support visual assessment or computer-aided diagnosis. In this paper a compact and descriptive feature set is presented. The feature extraction routines are based on two-dimensional color graphs called phonovibrograms (PVG). These graphs contain the full spatio-temporal pattern of vocal fold dynamics and are therefore suited to derive features that comprehensively describe the vibration pattern of vocal folds. Within our approach, clinically relevant features such as glottal closure type, symmetry and periodicity are quantified in a set of 10 descriptive features. The suitability for classification tasks is shown using a clinical data set comprising 50 healthy and 50 paralytic subjects. A classification accuracy of 93.2% has been achieved.

Risk factors for nasal malignancies in German men: the South-German Nasal cancer study

BACKGROUND

There are few studies of the effects of nasal snuff and environmental factors on the risk of nasal cancer. This study aimed to investigate the impact of using nasal snuff and of other risk factors on the risk of nasal cancer in German men.

METHODS

A population-based case-control study was conducted in the German Federal States of Bavaria and Baden-Württemberg. Tumor registries and ear, nose and throat departments provided access to patients born in 1926 or later.

RESULTS

Telephone interviews were conducted with 427 cases (mean age 62.1 years) and 2.401 population-based controls (mean age 60.8 years). Ever-use of nasal snuff was associated with an odds ratio (OR) for nasal cancer of 1.45 (95% confidence interval [CI] 0.88-2.38) in the total study population, whereas OR in smokers was 2.01 (95% CI 1.00-4.02) and in never smokers was 1.10 (95% CI 0.43-2.80). The OR in ever-smokers vs. never-smokers was 1.60 (95% CI 1.24-2.07), with an OR of 1.06 (95% CI 1.05-1.07) per pack-year smoked, and the risk was significantly decreased after quitting smoking. Exposure to hardwood dust for at least 1 year resulted in an OR of 2.33 (95% CI 1.40-3.91) in the total population, which was further increased in never-smokers (OR 4.89, 95% CI 1.92-12.49) in analyses stratified by smoking status. The OR for nasal cancer after exposure to organic solvents for at least 1 year was 1.53 (1.17-2.01). Ever-use of nasal sprays/nasal lavage for at least 1 month rendered an OR of 1.59 (1.04-2.44). The OR after use of insecticides in homes was 1.48 (95% CI 1.04-2.11).

CONCLUSIONS

Smoking and exposure to hardwood dust were confirmed as risk factors for nasal carcinoma. There is evidence that exposure to organic solvents, and in-house use of insecticides could represent novel risk factors. Exposure to asbestos and use of nasal snuff were risk factors in smokers only.

[Experience with individual obturators to treat nasal septum perforation]

BACKGROUND

Individual septal buttons have gained more attention during the last years. However, experiences in patients being treated by an individual septal button are limited. Therefore, further evaluation of this treatment option is needed.

MATERIAL AND METHODS

Records of 64 patients being treated by an individual septal button were evaluated retrospectively. As the silicon prints of the septum perforation were available size of the septal perforation were measured. Telephone interview were used to ask the patients about their general judgement and eff ect of the septal button on their different complaints.

RESULTS

Septumplasty in 42 patients and a trauma in 10 patients had been documented prior to treatment. In 7 patients Wegner's granulomatosis had been proven by serological and histopathological analysis. Digital manipulation and nasal drop abuses were judged to be the reason of the septal perforation in 2 patients each. In one patient the etiology remained unknown. Size of the septal perforation ranged from 7.4 to 807 mm(2). Using visual analog scale 42 patients reported to be highly satisfied. A statistically significant improvement was reported for all symptoms. Respiratory noise and nasal obstruction were improved best followed by nasal bleeding, pain and crust formation.

CONCLUSION

Treatment of septal perforations with individual septal buttons should be considered in treating septal perforations. Nasal obstruction and nasal bleeding were found to be improved best by this treatment option.

New genetic findings in parotid gland pleomorphic adenomas

BACKGROUND

Despite numerous studies, the tumor biology of pleomorphic adenomas, the most common salivary gland tumors, is still not completely defined. In order to identify further candidate genes important for tumor biology of pleomorphic adenomas, extended cytogenetic and molecular analysis are mandatory.

METHODS

We performed a detailed molecular cytogenetic analysis using comparative genomic hybridization (CGH) followed by fluorescence in situ hybridization (FISH) with probes for chromosome X, 16p, 17, and 20 on a large cohort of pleomorphic adenomas (n = 29).

RESULTS

We could confirm previously described deletions in pleomorphic adenomas affecting 16p, 17, 20q, and 22 by FISH and/or CGH analysis. Moreover, our CGH study revealed novel candidate regions on 8p23.1pter, 9p, 10q25.1q25.3, and 11q24qter in the series of analyzed pleomorphic adenomas.

CONCLUSION

Our present study reveals new insights in novel candidate regions implicated in pleomorphic adenoma tumorigenesis which should be considered in further molecular studies.

[Diagnosis and treatment of frontobasal cerebrospinal fluid fistulas]

Independent of its origin a frontobasal cerebrospinal fluid (CSF) fistula is characterized by an open connection between the intracranial space with the outside world (usually the nose and paranasal sinuses). It leads to loss of CSF and is associated with a significant risk of developing meningitis for the patient during further life. Precise knowledge of possible aetiologies, clinical symptoms, current diagnostic options and surgical strategies are essential for the detection and successful management of frontobasal CSF fi fistulas. This article summarizes aetiology and clinical signs of frontobasal CSF fistulas. Further, laboratory tests to analyse fluid samples for cerebrospinal fluid as well as radiological and endoscopic investigation methods aiming to localize a CSF-fistula are presented. Finally, surgical techniques to close a frontobasal CSF fistula are explained.

[First experience in endonasal surgery using a new 3D-Chipendoscope]

BACKGROUND

Endoscopic surgery for treatment of nasal, paranasal and anterior skull base pathologies is an established treatment modality. Available rigid endoscopes with angled views provide a 2-dimensional view with restriction of depth perception. In this study we report about our first experience with a new 3D-Chipendoscope in surgery at the nose, paranasal sinuses und anterior skull base.

MATERIAL AND METHODS

30 patients were enrolled in this study with chronic rhinosinusitis, inverted papilloma, frontal sinus mucocele, frontal sinus osteoma, chronic dacryocystitis and pituitary adenoma. All patients were subjected to standard endonasal endoscopic surgery using 3D-endoscopes.

RESULTS

Surgery was performed by the use of the 3D-endoscope in all patients. The operative handling of the 3D-endoscopes was user friendly in regard to design and weight of the endoscopes. The problem of fogging during endoscopic surgery diminishing the quality of view was not observed. Blood crusts on the endoscope tip however was able to changed the 3D-view to a 2D-view. To close positioning of the 3D-endoscopes to the surgical field reduced image quality. The visualisation of the frontal sinus was limited.

CONCLUSION

3D-endoscopic surgery is an interesting development in endonasal surgery of pathologies at the nose, paranasal sinuses and anterior skull base.

[Endoscopic frontal sinus revision following transcutaneous endoscopic puncture and diaphanoscopy]

BACKGROUND

Endoscopic revision sinus surgery in case of frontal sinus pyocele may poses a great surgical challenge for various reasons. Due to the often troublesome anatomical changes caused by prior resection and findings of scaring with new bone formation, the identification of the frontal sinus in revision surgery is frequently a challenge for the surgeon. An easy endoscopic technique for a safe endonasal identification of the frontal sinus in revision surgery is therefore of major importance.

MATERIAL AND METHODS

4 patients (3 men, 1 female) were enrolled with an acute frontal pyocele following prior open frontal sinus surgery over an external access. All patients were subjected to standard endonasal endoscopic frontal sinus surgery. The frontal sinus was endonasally approached after endoscopic transcutaneous frontal sinus puncture through the pre-existing bone defect achieving a diaphanoscopy with endonasal identification of the frontal sinus floor.

RESULTS

The external endoscopic puncture and illumination of the frontal sinus was performed in all 4 patients with a modular endoscopic system (Sinus View). A visual exploration of the frontal sinus was easily carried out after irrigation. A clear endonasal identification of the frontal sinus floor by diaphanoscopy was achieved in all patients and guided a direct opening of the frontal sinus. A stable frontal sinus drainage type IIb according to Draf was reached in all cases.

CONCLUSION

Transcutaneous frontal sinus puncture with an modular endoscope allows not only to verify frontal sinus pyocele diagnosis, but also provides the option to open the frontal sinus directly guided by the diaphanoscopy at the frontal sinus floor even in situations of complex anatomy.

Notched-Noise Embedded Frequency Specific Chirps for Objective Audiometry Using Auditory Brainstem Responses

It has been shown recently that chirp-evoked auditory brainstem responses (ABRs) show better performance than click stimulations, especially at low intensity levels. In this paper we present the development, test, and evaluation of a series of notched-noise embedded frequency specific chirps. ABRs were collected in healthy young control subjects using the developed stimuli. Results of the analysis of the corresponding ABRs using a time-scale phase synchronization stability (PSS) measure are also reported. The resultant wave V amplitude and latency measures showed a similar behavior as for values reported in literature. The PSS of frequency specific chirp-evoked ABRs reflected the presence of the wave V for all stimulation intensities. The scales that resulted in higher PSS are in line with previous findings, where ABRs evoked by broadband chirps were analyzed, and which stated that low frequency channels are better for the recognition and analysis of chirp-evoked ABRs. We conclude that the development and test of the series of notched-noise embedded frequency specific chirps allowed the assessment of frequency specific ABRs, showing an identifiable wave V for different intensity levels. Future work may include the development of a faster automatic recognition scheme for these frequency specific ABRs.

Anti-proliferative effect of glucocorticoids on mesenchymal cells in juvenile angiofibromas

BACKGROUND

Glucocorticoids (GCs) not only regulate metabolic and inflammatory mechanisms, but also are known to suppress tumor growth. Despite previous detection of glucocorticoid receptors (GRs) in juvenile angiofibromas, their distribution and function have not further been studied.

METHODS

Juvenile angiofibroma tissue (n = 30), nasal mucosa specimens (n = 10), subepithelial stroma of nasal mucosa (n = 20), and primary fibroblasts from juvenile angiofibroma (n = 6) and nasal mucosa samples (n = 6) were analyzed by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunofluorescence staining. The antiproliferative effect of GCs (dexamethasone, prednisolone, and hydrocortisone) in vitro was assessed using a bromdeoxyuridine (BrdU) assay.

RESULTS

An upregulation of GR transcripts and protein was shown in juvenile angiofibroma tissue and primary mesenchymal cells compared to nasal mucosa. Application of GCs resulted in a significantly higher antiproliferative effect on juvenile angiofibroma versus nasal mucosa fibroblasts in vitro.

CONCLUSION

Expression of GRs and antiproliferative effects of GCs on juvenile angiofibroma fibroblasts offer novel options for the treatment of this unique fibrovascular tumor.

Genome-wide copy number profiling using a 100K SNP array reveals novel disease-related genes BORIS and TSHZ1 in juvenile angiofibroma

Juvenile angiofibroma (JA) is a unique fibrovascular tumor, which is almost exclusively found in the posterior nasal cavity of adolescent males. Although histologically classified as benign, the tumor often shows an aggressive growth pattern and has been associated with chromosomal imbalances, amplification of oncogenes and epigenetic dysregulation. We present the first genome-wide profiling of JAs (n=14) with a 100K single nucleotide polymorphism (SNP) microarray. Among the 30 novel JA-specific amplifications detected on autosomal chromosomes with this technique, the genes encoding the cancer-testis antigen BORIS (brother of the regulator of imprinted sites) and the developmental regulator protein TSHZ1 (teashirt zinc finger homeobox 1) were selected for further analysis. Gains for both BORIS (20q13.3) and TSHZ1 (18q22.3) were confirmed by quantitative genomic PCR. Furthermore, quantitative RT-PCR revealed a significant up-regulation of BORIS (p<0.001) and TSHZ1 transcripts (p<0.05) for JAs compared to nasal mucosa. Following detection of BORIS and TSHZ1 proteins in western blots of JAs, subcellular localization was determined for both proteins in immunostaining of JA cryosections. In conclusion, genomic copy number profiling using an SNP microarray has been proven to be a suitable and reliable tool for identifying novel disease-related genes in JAs and newly implicates BORIS and TSHZ1 overexpression in the pathogenesis of JAs. Detection of BORIS in JAs is described with special regard to tumor proliferation and epigenetic dysregulation, and the finding of TSHZ1 amplifications is discussed with special respect to the hypothesis of JAs as malformations of the first branchial arch artery.

Papillary tumor of the temporal bone

Papillary tumors of the middle and inner ear have been interpreted histogenetically in many ways. In 1989 Heffner proposed the endolymphatic sac epithelium as a possible origin. These rare tumors are clinically aggressive and can cause extensive temporal bone destruction. Because of this behavior, endolymphatic sac tumors (ELST) were classified as low-grade adenocarcinomas, although metastasis has not yet been documented. Two papillary neoplasms of the temporal bone are presented, which we believe are examples of adenomatous tumors arising from the epithelium of the endolymphatic sac. One was associated with a pituitary adenoma. A third case of a papillary middle ear neoplasm is described that shows histologic features similar to the other two, but it was located in the tympanum and had no connection to the endolymphatic sac. This report focuses on clinical, radiologic, and histologic findings of papillary tumors of the temporal bone with additional emphasis on modern concepts of histogenesis and aspects of differential diagnosis.

Late manifestations of traumatic lesions of the anterior skull base

The authors review their experience in detecting occult traumatic dural lesions. In a retrospective study covering the period from January 1, 1984 to December 31, 1996, 23 patients were evaluated for occult traumatic dural lesions. Clinical presentation, diagnostic work-up, and management of the dural lesions were analyzed.The clinical presentations of the previously undetected dural lesions of the anterior skull base were meningitis in eight cases, cerebrospinal fluid (CSF) rhinorrhea in eight cases, both meningitis and CSF rhinorrhea in five cases, and a pulsating swelling in the region of the right upper eyelid in one case. In another case a fracture of the posterior frontal wall was detected incidentally on the preoperative CT scan performed prior to surgery for chronic sinusitis. One patient had a CSF fistula of the lateral skull base in addition to the frontobasal fistula. The interval between trauma and diagnosis varied from 1 to 48 years. Dural lesions were localized by high-resolution CT, fluorescein nasal endoscopy, CT cisternography, and MRI. Intraoperative exposure of the dural lesions and duraplasty were possible in all cases. During the first attempt successful repair of the dural lesions was accomplished in 22 (95.7%) of the 23 patiants. Two interventions were necessary to close a CSF leak of the cribriform plate.Modern clinical and radiologic diagnostic methods should be employed to search for an occult dural lesion in patients with recurrent meningitis, meningitis caused by upper airway pathogens, or CSF rhinorrhea. The patient will remain at risk of potentially fatal meningitis until the lesion is appropriately repaired by duraplasty.

How I do it: endoscopic-microscopic anterior skull base reconstruction

Reconstruction of the anterior skull base must be secure and watertight. Failure to achieve this places the patient at risk of the development of cerebral sepsis. We have developed the technique of endonasal duraplasty and have achieved a 90% long-term success rate. In this article we described the key elements of our technique starting with radiographic and fluorescein localization of a skull base defect. The main steps in reconstruction and materials used are detailed, together with modifications of our technique for certain difficult situations and tips for success. Attention is drawn to potential pitfalls that have been identified over 25 years of clinical practice.

A new method to analyze distortion product otoacoustic emissions (DPOAEs) in the high-frequency range up to 18 kHz using windowed periodograms

Distortion product otoacoustic emissions (DPOAEs) are widely used as an objective examination procedure to determine cochlear function. In a clinical routine setting, the amplitude of the DPOAE signal at 2f1 .. f2 is applied as an indicator for a potential hearing loss up to 8 kHz. Due to their poor signal to noise ratio, meatal nodes from standing waves and calibration issues, high-frequency DPOAEs > 8 kHz have hardly been addressed in experimental and clinical audiology so far. Here, we present a new method of measuring DPOAE signal levels based on optimal maximum likelihood estimation with windowed power spectral density estimation of stochastic signals and filtering theory. Analysis of simulated data showed that the proposed method effectively reduces the disturbing noise floor compared to conventional averaging techniques. Robust DPOAE signals were measured in 20 ears from 10 normally hearing young adults (21 to 27 years) from 0:5 to 18 kHz. Repeated DPOAE recordings in one individual yielded a good to very good testretest reliability of the proposed method. These observations are discussed in the context of DPOAE signal processing and possible clinical applications of high-frequency DPOAE measurements.

A kernel-based novelty detection scheme for the ultra-fast detection of chirp evoked Auditory Brainstem Responses

Auditory Brainstem Responses (ABRs) are used as objective method for diagnostics and quantification of hearing loss. Many methods for automatic recognition of ABRs have been developed, but none of them include the individual measurement setup in the analysis. The purpose of this work was to design a fast recognition scheme for chirp-evoked ABRs that is adjusted to the individual measurement condition using spontaneous electroencephalographic activity (SA). For the classification, the kernel-based novelty detection scheme used features based on the inter-sweep instantaneous phase synchronization as well as energy and entropy relations in the time-frequency domain. This method provided SA discrimination from stimulations above the hearing threshold with a minimum number of sweeps, i.e., 200 individual responses. It is concluded that the proposed paradigm, processing procedures and stimulation techniques improve the detection of ABRs in terms of the degree of objectivity, i.e., automation of procedure, and measurement time.