Hans Wilhelm Pau

Noise Exposure of the Inner Ear During Drilling a Cochleostomy for Cochlear Implantation

Objectives: Inserting an electrode array into the cochlea may cause inner ear trauma, which has to be minimized, particularly in cochlear implant patients with substantial residual hearing. Another potential inner ear trauma has, to a large extent, been neglected so far: the acoustic trauma that can occur during cochleostomy using different techniques. In this study, the noise exposure of the inner ear during the drilling procedure was re‐evaluated. In experiments on temporal bones, quantitative measurements of sound pressure level (SPL) were carried out while a cochleostomy for cochlear implantation was drilled.

Cephalic phase insulin release in healthy humans after taste stimulation

In humans little is known as to whether taste solutions applied to the tongue elicit cephalic phase insulin release (CPIR). The aim of this study was to re-examine if any effect of different taste solutions on CPIR occurs. Under fasting conditions healthy human subjects sipped, and washed out their mouths with eight taste solutions (sucrose, saccharin, acetic acid, sodium chloride, quinine hydrochloride, distilled water, starch, and sodium glutamate) for 45 s and spat them out again. The taste stimuli were not swallowed; they were applied in a randomized order, each on a separate day. Blood collection for determination of plasma glucose and plasma insulin concentrations was performed 3 min before and 3, 5, 7 and 10 min after taste stimulation. Ratings of quality, intensity and hedonic characteristics were also obtained. A significant increase of plasma insulin concentration was apparent after stimulation with sucrose and saccharin. In conclusion, the current data suggest that the sweeteners sucrose and saccharin activate a CPIR even when applied to the oral cavity only.

Intracellular persisting Staphylococcus aureus is the major pathogen in recurrent tonsillitis.

Background The two major indications for tonsillectomy are recurrent tonsillitis (RT) and peritonsillar abscess (PTA). Unlike PTAs, which are primarily treated surgically, RT is often cured by tonsillectomy only after a series of failed drug therapy attempts. Although the bacteriological background of RT has been studied, the reason for the lack of success of conservative therapeutic approaches is not well understood. Methods In a prospective study, tonsil specimens from 130 RT patients and 124 PTA patients were examined for the presence of extra- and intracellular bacteria using antibiotic protection assays. Staphylococcus aureus isolates from RT patients were characterized by pulsed-field gel electrophoresis (PFGE), spa-typing and MSCRAMM-gene-PCR. Their ability for biofilm formation was tested and their cell invasiveness was confirmed by a flow cytometric invasion assay (FACS), fluorescent in situ hybridization (FISH) and immunohistochemistry. Findings S. aureus was the predominant species (57.7%) in RT patients, whereas Streptococcus pyogenes was most prevalent (20.2%) in PTA patients. Three different assays (FACS, FISH, antibiotic protection assay) showed that nearly all RT-associated S. aureus strains were located inside tonsillar cells. Correspondingly, the results of the MSCRAMM-gene-PCRs confirmed that 87% of these S. aureus isolates were invasive strains and not mere colonizers. Based upon PFGE analyses of genomic DNA and on spa-gene typing the vast majority of the S. aureus isolates belonged to different clonal lineages. Conclusions Our results demonstrate that intracellular residing S. aureus is the most common cause of RT and indicate that S. aureus uses this location to survive the effects of antibiotics and the host immune response. A German translation of the Abstract is provided as supplementary material (Abstract S1).

Contact Endoscopic Comparison of Morphology of Human Fungiform Papillae of Healthy Subjects and Patients with Transected Chorda Tympani Nerve

Background: The chorda tympani nerve (CTN) carries gustatory fibers from taste buds of fungiform papillae (fPap) of the anterior portion of the tongue. Accordingly, middle ear surgery with transection of the CTN may result in gustatory impairment. With use of contact endoscopy, the present study aimed to compare number and shape of fPap and subepithelial vessel formation in patients after CTN transection with that of healthy controls.

Confocal microscopy of the peripheral gustatory system : Comparison between healthy subjects and patients suffering from taste disorders during radiochemotherapy

Objectives: Laser‐scanning microscopy (LSM) was used to compare taste buds and epithelia of fungiform papillae of healthy subjects with those of patients suffering from taste disorders during/after radiochemotherapy (RCT). Aim of the study was to investigate effects responsible for taste loss at a microscopic level.

In vivo observation of papillae of the human tongue using confocal laser scanning microscopy.

The aim of this investigation was to visualize the epithelial structures of the tongue using confocal laser scanning microscopy (LSM). The human tongue epithelium of 28 healthy subjects, aged 21–67 years, mean age 38 years, 14 women and 14 men, was examined in vivo by LSM. Using LSM, a combination of the Heidelberg Retina Tomograph HRT II and the Rostock Cornea Module, up to 800-fold magnifications were obtained. On the tongue surface both filiform and fungiform papillae and their taste pores were easily identified. The epithelium of the tongue with its subcellular structures could be observed up to a depth of 50 µm, cellular structures up to 150 µm and subepithelial vessels up to 300 µm. Additionally the papillary crests and blood flow were visible. Confocal LSM seems suitable for noninvasive in vivo examination of the tongue. The hydraulic z scan, the manual start setting and the measurement of the depth allow a clear classification of the observed structures.

Can mobile phone emissions affect auditory functions of cochlea or brain stem

PROBLEMS ADDRESSED: Despite their abundant spread, mobile phones are suspected by a major share of the population to cause adverse effects on health and welfare. The ear as the sense organ next to the individual device has rarely been Investigated for short-term effects in this regard. In a previous article, we could not prove any impact on the vestibular part of the inner ear. Our present examinations are concerned with the question whether mobile phone emissions could affect cochlear or auditory brain stem functions. METHODS AND MEASURES: In 12 healthy test persons with normal hearing, auditory brain stem reflexes recordings were performed before, during, and after exposure to electromagnetic emissions by standardized mobile phone devices. Two modes of electromagnetic emissions fields were administered: pulsed and continuous. For acoustic stimulation simultaneous to field exposure, special “plug-in” earphones had to be used. RESULTS: No impact on auditory brain stem reflexes recordings in terms of absolute and interpeak latencies could be found. CLINICAL SIGNIFICANCE: Together with the results of a previous article concerned with the vestibular part of the inner ear, we can state that there are no adverse effects of mobile phone emissions on the ear function, at least on a short-term range. Of course, any long-term effects cannot be excluded by our study.

Third window vibroplasty: an alternative in surgical treatment of tympanosclerotic obliteration of the oval and round window niche.

Objective: To describe a new technique in surgical treatment of obliterative tympanosclerosis by applying a floating mass transducer (FMT) to a third window. Patient: A 64-year-old woman with a severe combined hearing loss due to tympanosclerosis received a third window vibroplasty. Intervention: A mastoidectomy and a posterior tympanotomy via the large facial recess were performed. The promontory was exposed by a transcanal approach. The third window was performed anterior inferior to the round window. The membranous cochlea was left intact. The FMT was gently pushed into the perichondrium-coated cochlear window. All other surgical steps were the same as in conventional FMT application. Results: Preliminary data of this report reveal that vibroplasty with coupling of the FMT directly to a third window leads to similar audiological results compared with the conventional coupling of the FMT on the round window niche. Conclusion: The presented case demonstrates the applicability of a third window vibroplasty in obliterative tympanosclerosis. Further studies will show if our assumption of a reduced risk for inner ear trauma is justified or not.

Optical coherence tomography as an orientation guide in cochlear implant surgery

Conclusion: With optical coherence tomography (OCT) it is basically possible to reveal parts of the cochlear morphology without opening its enveloping membranes. Thus, it may serve as a helpful guide for the surgeon to localize the scala tympani precisely before opening the fluid-filled inner ear to insert the electrode array. Objective: To improve anatomical orientation in cochlear implant surgery before definitively opening the fluid-filled inner ear. The question was whether a new imaging technique, OCT, might provide information about the site of the underlying inner ear structures (scala tympani, scala vestibuli) and could, consequently, guide the surgeon towards the scala tympani. Materials and methods: In a preliminary study, OCT was carried out on human temporal bone preparations, in which a cochleostomy (‘fenestration’) was performed leaving the endosteum and the fluid-filled inner ear intact. OCT was applied via a prototype of a specially equipped operating microscope. The mode of OCT used in this context was spectral-domain (SD)-OCT. Results: On scans, which can be read analogous to B-mode sonography, OCT provides information about structures on the inner surface of the partly exposed but still intact membranous cochlear lining – such as scala tympani or scala vestibuli.

Pressure changes in the human middle ear without opening the eustachian tube.

Conclusion. By means of a direct, though non-invasive experiment on healthy humans we could demonstrate that middle ear (ME) pressure decreases when the eustachian tube (ET) does not open. Thus with a very simple method the basic theory of continuous gas loss from the ME into the circulation and the replenishment of the loss through the ET could be validated. Objectives. To record changes in ME pressure over a period of time in normal human ears, while the ET is kept closed. Subjects and methods. On-line tympanometry was carried out in three subjects, who refrained from swallowing for 20–120 min. Results. During the time when the ET was kept closed by refraining from swallowing, tympanometric monotonous pressure decrease was recorded. Once the tested subject could not refrain from swallowing any longer and swallowed again, ME pressure equalized immediately.