F. W. J. Albers

The effect of buttermilk consumption on biofilm formation on silicone rubber voice prostheses in an artificial throat.

Abstract Biofilm formation on indwelling silicone rubber voice prostheses in laryngectomized patients is still the main reason for dysfunction of the valve, leading to frequent replacements. Within patient support groups in The Netherlands, laryngectomees have suggested that the consumption of buttermilk prolongs the life-time of indwelling silicone rubber voice prostheses. The aim of the present study was to compare biofilm formation on Groningen button voice prostheses in a so-called artificial throat. Ten prostheses were placed in a simulated control group and ten other prostheses in a group with a simulated consumption of 700 ml buttermilk three times a day. Biofilms were allowed to grow on the prostheses by inoculating two artificial throats with the total cultivable microflora (bacteria and yeasts) isolated from an explanted Groningen button voice prosthesis. After 3 days, one artificial throat was perfused three times daily with phosphate buffer (control group) for 8 days, while the other artificial throat was perfused with buttermilk. Prostheses removed from the artificial throat in the control group were covered with a thick biofilm. Scanning electron microscopy showed microcolonies growing into the silicone rubber, similar to the ingrowth observed on explanted Groningen buttons. The simulated consumption of buttermilk in the other artificial throat almost fully prevented the formation of a biofilm on the prostheses during the experimental period. These in vitro experiments in the artificial throat demonstrate that the deterioration of voice prostheses can be lessened by the daily intake of buttermilk through its inhibitory effects on biofilm formation.

The treatment of idiopathic sudden sensorineural hearing loss using pulse therapy: A prospective, randomized, double-blind clinical trial

Objectives: The etiology and treatment of idiopathic sudden sensorineural hearing loss (ISSHL) is still unclear. The anti‐inflammatory effect of corticosteroids is thought to play an important part in the recovery from ISSHL. We aimed to determine whether a more powerful anti‐inflammatory technique using pulse therapy is effective in the treatment of ISSHL.

Antimicrobial activity of synthetic salivary peptides against voice prosthetic microorganisms

Objectives: To investigate whether synthetic salivary antimicrobial peptides have an inhibitory effect on the growth of bacteria and yeasts isolated from used silicone rubber voice prostheses.

The distressed (Type D) personality is independently associated with tinnitus : A case-control study

BACKGROUND Tinnitus is a common and disturbing condition, reported by 10% to 20% of the general population. OBJECTIVE The authors sought to determine personality characteristics associated with tinnitus patients versus a control group of ear-nose-throat (ENT) patients without tinnitus. METHOD Adult chronic tinnitus sufferers (N=265) and ENT patients without tinnitus (N=265) participated in a cross-sectional study. The authors evaluated personality characteristics with tests for distressed personality (Type D), neuroticism, extraversion, and emotional stability. RESULTS As compared with control subjects, tinnitus patients had statistically significant and clinically relevant higher levels of neuroticism, negative affectivity, and social inhibition, on one hand, and lower levels of extraversion and emotional stability on the other hand. Also, tinnitus patients were more likely to have a type D personality. CONCLUSIONS Neuroticism, reduced extraversion, and reduced emotional stability were associated with tinnitus, but the level of prediction of the model improved with the addition of type D personality to the single traits. This might indicate that personality characteristics, and type D personality, in particular, are associated with having tinnitus and might contribute to its perceived severity.

3DFT-magnetic Resonance Imaging of the Inner Ear in Meniere's Disease*

Three dimensional Fourier transformation constructive interference in steady state (3DFT-CISS) magnetic resonance imaging (MRI) allows a detailed visualization of the membranous labyrinth of the inner ear. In this study the endolymphatic duct and sac is investigated in patients with Menières disease using 3DFT-CISS MRI. In addition, the distance between the vertical part of the posterior semicircular canal and the fossa posterior is quantified.

Neural responses to silent lipreading in normal hearing male and female subjects

In the past, researchers investigated silent lipreading in normal hearing subjects with functional neuroimaging tools and showed how the brain processes visual stimuli that are normally accompanied by an auditory counterpart. Previously, we showed activation differences between males and females in primary auditory cortex during silent lipreading, i.e. only the female group significantly activated the primary auditory region during lipreading. Here we report and discuss the overall activation pattern in males and females. We used positron emission tomography to study silent lipreading in 19 normal hearing subjects (nine females). Prior to scanning, subjects were tested on their lipreading ability and only good lipreaders were included in the study. Silent lipreading was compared with a static image. In the whole group, activations were found mainly in the left hemisphere with major clusters in superior temporal, inferior parietal, inferior frontal and precentral regions. The female group showed more clusters and these clusters were larger than in the male group. Sex differences were found mainly in right inferior frontal and left inferior parietal regions and to a lesser extent in bilateral angular and precentral gyri. The sex differences in the parietal multimodal region support our previous hypothesis that the male and female brain process visual speech stimuli differently without differences in overt lipreading ability. Specifically, females associate the visual speech image with the corresponding auditory speech sound whereas males focus more on the visual image itself.

Functional sex differences in human primary auditory cortex

BackgroundWe used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation).Results and discussionWe found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC.ConclusionOur results suggest that sex is an important factor in auditory brain studies.

Long-term evaluation of treatment of chronic, therapeutically refractory tinnitus by neurostimulation.

Objective: Long-term evaluation of treatment of chronic, therapeutically refractory tinnitus by means of chronic electrical stimulation of the vestibulocochlear nerve. Patients: Inclusion criteria were severe, chronic, therapeutically refractory, unilateral tinnitus and severe hearing loss at the ipsilateral site. Out of 6 patients, 4 patients were selected for long-term evaluation. Two patients were not evaluated because of premature dropout. Material and Methods: A stimulation electrode was placed around the vestibulocochlear nerve through a retrosigmoid approach and connected to a subcutaneously positioned pulse generator via an extension cable. Follow-up was performed 3 months and 42.5 months after implantation. Three measures for treatment outcome were used. First, effect sizes were determined by means of the total Tinnitus Handicap Inventory (THI) score using Cohen’s formula. Second, general and tinnitus-specific audiometric tests were performed in on and off conditions of the neurostimulation system. Third, recordings were noted for tinnitus severity and treatment success on a visual analogue scale. Results: All 4 patients reported successful treatment with neurostimulation. The effect size after 3 months was 0.7, indicating an average effect, while the effect size measured during long-term follow-up was 1.75, indicating a substantial effect with major clinical implications. No changes in hearing level for both ears were measured. The neurostimulation system did not change the tinnitus pitch in any of the patients, and resulted in a minimal reduction of tinnitus loudness in only 2 patients. In all 4 patients the original tinnitus sound was replaced by another, pleasantly perceived sound. The average VAS score of perceived tinnitus severity was reduced from 8 to 3.25. The average VAS score for treatment success was 7.25. Conclusions: The long-term follow-up of neurostimulation treatment for chronic tinnitus shows promising results. Long-term results were better than those determined after a 3-month follow-up. In all patients the tinnitus was replaced by another sound, which was perceived as pleasant. Further studies are needed before accepting neurostimulation as a treatment modality for chronic, therapeutically refractory tinnitus.

Dynamics of Inner Ear Pressure Change Caused by Intracranial Pressure Manipulation in the Guinea Pig

Previous studies have shown that pressure changes in the cerebrospinal fluid compartment are transmitted to the inner ear. The main route for pressure transfer is the cochlear aqueduct, about which little is known with regard to its dynamic properties. In the present study, sudden intracranial pressure changes (square waves and short pulses) were created in guinea pigs by means of an electronically controlled infusion system. Simultaneously with pressure manipulation, hydrostatic pressure was monitored in both the peridural space and the perilymphatic compartment of the inner ear. The onset of an inner ear pressure change following manipulation of intracranial pressure was immediate. Inner ear pressure increased or decreased without a measurable time lag, and equalized within a few seconds. During square wave intracranial pressure manipulation, inner ear pressure equalized somewhat more slowly after pressure increase than after pressure decrease. To a first approximation, the pressure equalization curves for the inner ear could be fitted with a single exponential function, rising or falling with a time constant in the range 1-3 s, and the system can be described as a low-pass filter composed of a constant compliance and a constant flow resistance. Detailed analysis, however, showed small deviations from a purely exponential recovery process. With a more complicated (non-linear) model, almost perfect fits to the inner ear pressure equalization curves could be obtained. This non-linearity may be a consequence of the dependence of the compliance and/or flow resistance on pressure.

Functional imaging of the central auditory system using PET

In the last few decades functional neuroimaging tools have emerged to study the function of the human brain in vivo. These techniques have increased the knowledge of how the brain processes stimuli of different sensory modalities, including auditory processing. Positron emission tomography (PET) has been used for nearly 20 years to study changes in cerebral blood flow associated with auditory stimulation in normal and hearing impaired subjects. PET studies gave insight into the neural base of processing basic sound features such as frequency and intensity, but complex stimuli such as speech and music have also been investigated extensively. Knowledge of the normal auditory function of the brain helps us to understand the neural base of hearing deficits and provides ideas for possible treatments. Although functional magnetic resonance imaging (fMRI) is replacing PET in many neuroimaging studies nowadays, PET still holds unique advantages and can give us valuable knowledge about the auditory cortex and auditory perception.