Biomedical subjects
Publications and source records attributed to M Ptok.
The objective of the present paper is to describe a soft palate level device, the veloretractor, which is a combination of orthodontic appliance and therapeutic aid in speech therapy. Its use is demonstrated in a case report of a child with complete bilateral cleft lip and palate. Both orthodontic and phoniatric/pedaudiologic treatment needs during the course are demonstrated along with the treatment results.
UNLABELLED: PRELIMINARY REMARKS: The prevalence of central auditory processing disorders (CAPD) is supposed to be 2-3% of all children. Given the number of affected children and restricted resources in the public health there is a need for an effective and evaluated therapeutic approaches. On the other hand the number of outcome studies is remarkably small. PATIENTS AND METHODS: The presented study reports strategies and pitfalls in outcome measurements of 34 children with CAPD, based upon a 3-weeks indoor therapeutic intervention. Diagnostic criteria of auditory processing and perception were recorded before and after therapy. RESULTS: The data shows a highly significant improvement of certain perceptive abilities, including audiological parameters (dichotic testing, discrimination, loudness scaling) and awareness, psycholinguistic development and orthographic tests. CONCLUSION: The study demonstrates that an effective therapy of CAPD in children is possible and scientifically proven. Long term surveillance however seems to be necessary. It also has to be studied whether intensive indoor treatment is superior or equal to out clinic therapy.
BACKGROUND: Upper airway obstruction due to bilateral vocal cord paralysis in an 80-year-old female patient was successfully relieved by injection of botulinum toxin A (BTA) into the laryngeal adductor muscles. The patient achieved satisfactory airway ventilation. Spirograms obtained preoperatively and postoperatively documented improved peak flow rates and 1-s forced expiratory volume values. Voice quality was breathy after the injection; however, neither aspiration nor dysphagia developed. Surprisingly, the maximum phonation time increased. PATIENTS AND METHODS: During a follow-up check 4 months later, the patient still reported less dyspnea although the vocal cords were closer together than initially after the injection. The decrease in dyspnea as reported by the patient lasted approximately 2 years. RESULTS: The improvement in breathing following injection of BTA can be interpreted as a paralysis or weakening of the laryngeal adductors. However, it remains unclear why the maximum phonation time increased. Comparable findings, i.e., improvement in overall laryngeal function, are described in the literature as BTA-mediated laryngeal rebalancing.
BACKGROUND: The purpose of the study was to analyze if perceptual voice quality ratings of the well-known RBH rating procedure (a 4-point scale of roughness, breathiness, and hoarseness) covary with acoustical voice parameters. METHODS: 120 voice samples from subjects with healthy and hoarse voices were rated on the RBH-index in a multicenter study with 31 raters. Multivariate regression tree analysis classified the perceptual ratings as "gold standard". Voice samples were acoustically analyzed with a feature extraction method. Feedforward-networks were trained to selected acoustical parameters having highest "relative importance" in the regression trees. Based on the best classifier, a computer program consisting of 50 simultaneous working networks was developed. RESULTS: Mean probabilities for correct classifications were found at 0.65-0.85, implying a significance level over chance (0.25). Classifications of the program matched in 40% with a priori values in the categories roughness combined with breathiness, and in 65% in at least one domain. CONCLUSIONS: The new method described here provides a psychoacoustically based "objective" classification of hoarse voices, which seems to enable future analysis of new parameters (like GNE), which may even improve the present results.
The combined findings of "normal evoked otoacoustic emissions (EOAE) and absent or markedly disturbed auditory evoked potentials from the brainstem and/or cortex" has been named auditory neuropathy in the English literature. The pure tone thresholds in these patients range from mild to severe loss. The loss of speech comprehension is out of proportion in comparison to the pure tone threshold elevation. This combination of findings suggests that cochlear function and in particular outer hair cell function, is normal in these patients but also suggests that the inner hair cell / VIII nerve functional unit is abnormal. Disruption in neural synchrony has previously been postulated as a reasonable explanation for the absent auditory brainstem response while otoacoustic emissions are preserved. Because the long-latency auditory evoked potentials, not having the stringent synchrony requirements of the ABR, may also be missing, the term synchrony - disruption may be somewhat misleading. The literature about auditory neuropathy is reviewed here: We now know that a set of salient features distinguishes these patients from the majority of patients with sensorineural hearing loss or other described syndromes. The symptoms defining auditory neuropathy are mild, moderate or severe elevation of auditory thresholds to pure tone stimuli by air and bone conduction, absent to severely abnormal ABRs to high level stimuli, present otoacoustic emissions (that do not suppress with contralateral noise), word recognition ability poorer than expected from the pure tone hearing loss configuration (in cases with mild to moderate hearing threshold elevation) and absent acoustic reflexes to both ipsilateral and contralateral tones. The entire set of findings, consistently seen in these patients, supports the importance of the crosscheck principle in diagnostic evaluation especially in children with delayed and/or impaired language acquisition. It is of ponderous importance that this disorder is not being confused with sensory hearing loss.
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Distal renal tubular acidosis is characterized by an impaired H(+)-ion secretion in the distal tubulus. This may cause metabolic acidosis. Among others, patients suffer from retardation and nephrocalcinosis. Here we report about a 3 years old patient with drtA and sensorineural hearing loss. ATP6B1 gene mutation was recently found in patients with drtA sensorineural hearing loss. ATP6B1 expression was demonstrated immunohistochemically in the mouse cochlea and endolymphatic sac. ATP6B1 mRNA was found in the fetal and adult human cochlea. These findings suggest that sensorineural hearing loss in drtA is caused by an disturbed pH homeostasis induced by ATP6B1 mutation.
Perceptual rating scales are widely used for the assessment of voice quality. These ratings may be influenced by the individual experience of the listener. Thus, researchers have turned to acoustical measures which may eventually correlate with voice quality. In this study we tested whether multivariate statistics, combined with artificial neural networks, could identify patterns of acoustic voice parameters corresponding to a widely used perceptual rating scale. In a multicenter study with 31 raters, voice samples of 117 individuals with or without voice disorders were perceptually rated. The RBH index, consisting of a 4-point scale of roughness, breathiness, and hoarseness, was used. Voice samples were then analyzed with an acoustical feature extraction and classified using amultivariate regression tree analysis with the perceptual ratings as a priori information. Artificial neural networks were trained to selected acoustic parameters having high "relative importance" in the regression trees. Mean classification accuracies were around 30% with topographic feature maps (trained with Learning Vector Quantization algorithm) and 65-85% with feedforward networks (trained with RProp algorithm). Based on the best-fitting results with feedforward networks, a classification system (computer program) consisting of 50 simultaneous working networks was developed. Using this program, the classification matched 40% of the a prori values in both R and B domains. In 65% they matched at least in one domain. These accuracies are within the range reported by other authors using artificial neural networks in biology and clinical medicine. Thus, the results encourage further research of feedforward networks for acoustic voice analysis.
Many cleft palate teams currently schedule palatoplasty and veloplasty within the child's first year of life. At Hannover Medical School, palatoplasty and veloplasty are performed at approximately 18-24 months of age. It was questioned which speech and language outcome was achieved and whether it may be influenced by: (1) type and extent of the clefts; (2) velopharyngeal inadequacy; and (3) hearing disorders. A retrospective evaluation of data collected from 1985 to 1993 was performed summarizing receptive and expressive speech and language skills of 370 children aged 4.5 years. Cleft types were unilateral cleft lip and palate (UCLP, 30.0%), bilateral cleft lip and palate (BCLP, 28.7%), cleft hard and soft palate (CP, 21.6%), cleft soft palate (cleft velum, CV, 10.8%), cleft lip and alveolus (CLA, 5.8%) and submucous clefts (SUB, 3.2%). n = 86 had constant normal hearing, and n = 284 had conductive hearing loss > 20 dB (500-4000 Hz). Severe developmental phonology errors were found in 30-50% of children with repaired cleft palate and in less than 8% of patients with CLA and SUB. Posterior compensatory misarticulation was below 15% in the groups UCLP, BCLP, CP, CV and SUB. Nasal resonance and air emission was nearly normal in CLA, but was increased in 27% to 38% of the other cleft types. Children with conductive hearing loss had significantly more and severely affected phonology, morphology, syntax, vocabulary, language comprehension, and auditory perception than normal hearing children. Findings indicated that speech and language function in CLP patients were predominantly related to the hearing status.
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A total of 1528 pre-school children (mean age 4 years and 9 months), being identified as speech or language delayed, were evaluated with respect to micro-otoscopy, nose and throat pathology, hearing function, and speech-language abilities. Subjects were classified into groups of (I) constant normal hearing, (II) fluctuating conductive hearing loss and (III) bilateral moderate to profound sensorineural hearing loss requiring hearing aids. In groups II and III, severe speech and language pathologies were found more frequently than in group I. Additionally, auditory perception skills were less in group II, even if peripheral hearing function was normalized. Group III was affected more than group II, but not significantly. The results indicate that in children having speech or language delay for severals reasons, mild fluctuating hearing loss can additionally alter language acquisition, but less than in cases of moderate or profound sensoneurinal hearing loss. The need of early detection of sensoneurinal hearing loss appears widely accepted; this study demonstrates also the necessity of early diagnosis of mild fluctuating hearing loss, especially in children with speech-language delay.
Patients with adductor type spasmodic dysphonia (SD) often exhibit both glottal and supraglottal hyperfunction. Based on the hypothesis that a "ventricular muscle" may contribute to the hyperfunction in these cases, eight patients with adductor type SD were treated with bilateral injection of botulinum toxin type A into the ventricular folds. Four weeks after injection, ventricular fold hyperfunction was absent in all cases. Number of voice breaks, standard deviation of fundamental frequency, and shimmer were significantly improved. Voice range profiles of the speaking voice were significantly extended in dynamic and frequency range. Side effects were a breathy phonation and mild swallowing difficulties without aspiration for about 1 week. Patients' self-rating concerning strangled and breathy voicing demonstrated an interval of acceptable voice quality between 1 week and 4 months after injection in all cases. Results suggest that supraglottal injection in patients with SD of both glottal and supraglottal hyperfunction, as a new approach, can normalize supraglottal activity and improve glottal voicing. Based on our experience with other patients with adductor type of SD, this injection technique is as efficient as injection into the thyroarytenoid muscle. Nevertheless, it remains to be proved that a pathologic ventricular muscle activity is addressed by this technique or if it is based on spreading to the thyroarytenoid muscle.
Transient click-evoked otoacoustic emissions (TEOAE) and distortion-product otoacoustic emissions (DPOAE) are produced by an active biomechanical process in the cochlea, presumably related to outer hair-cell activity. Although it is generally accepted that in most cases of hearing loss with absent auditory evoked potentials neither TEOAE nor DPOAE can be found, some cases with such a constellation have been described. Here we report another four cases of children with severe to profound hearing loss where we discovered reproducible TEOAE and DPAOE, whereas auditory evoked potentials were missing. TEOAE and DPOAE recordings in these cases indicate substantially preserved outer hair-cell function independent of profound pre-sensineural hearing loss. Since the incidence of children with preserved otoacoustic emissions together with impairment of synaptic or postsynaptic function of the first neuron is not known, the unconditioned use of TEOAE nor DPOAE as a screening instrument must be seriously questioned. Secondly, in conjunction with subjective audiometry and brain-stem-evoked potentials, emission recordings is an indispensable measurement prior to cochlear implantation and use of high-power hearing aids.
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Neuronal networks are computer-based techniques for the evaluation and control of complex information systems and processes. So far, they have been used in engineering, telecommunications, artificial speech and speech recognition. A new approach in neuronal network is the self-organizing map (Kohonen map). In the phase of 'learning', the map adapts to the patterns of the primary signals. If, the phase of 'using the map', the input signal hits the field of the primary signals, it resembles them and is called a 'winner'. In our study, we recorded the cries of newborns and young infants using digital audio tape (DAT) and a high quality microphone. The cries were elicited by tactile stimuli wearing headphones. In 27 cases, delayed auditory feedback was presented to the children using a headphone and an additional three-head tape-recorder. Spectrographic characteristics of the cries were classified by 20-step bark spectra and then applied to the neuronal networks. It was possible to recognize similarities of different cries of the same children as well as interindividual differences, which are also audible to experienced listeners. Differences were obvious in profound hearing loss. We know much about the cries of both healthy and sick infants, but a reliable investigation regimen, which can be used for clinical routine purposes, has yet not been developed. If, in the future, it becomes possible to classify spectrographic characteristics automatically, even if they are not audible, neuronal networks may be helpful in the early diagnosis of infant diseases.
The larynx can be divided into a supraglottic, a glottic and a subglottic area, each serving different functions. In many cases of laryngitis the site of infection is located in one area, leaving other areas unaffected. It seems reasonable to speculate that the underlying cause of the heterogeneous infection pattern in the larynx is the different processing of infectious agents. Therefore, the number and distribution of granulocytes, macrophages, dendritic cells, natural killer cells and T and B lymphocytes in the normal laryngeal mucosa of young rats were studied. The results show that, with the exception of granulocytes, all subpopulations were present in different numbers. Many macrophages and dendritic cells but only a few natural killer cells and T and B lymphocytes were located in the mucosa. Dendritic cells, natural killer cells and T and B lymphocytes were rarely present in the vocal fold area, whereas in the subglottic area they were present in high numbers. Thus, differences in the composition of immunocompetent cell populations between laryngeal areas were detectable.
Radical orofacial tumor resections often result in speech and swallowing dysfunctions. Thus, both communication ability and life quality can be markedly impaired in patients. Dysfunction is mostly related to the amount of tissue removed and the reconstruction technique used. In this prospective study, pre- and postoperative speech intelligibility following reconstruction with either local grafts, free jejunal flaps or myocutaneous/fasciocutaneous flaps was examined by subjective assessment of monosyllables chosen from the Freiburg audiometry test ("reverse speech intelligibility test"). It was shown that linguodental affricates and dorsofaucal plosives were especially affected, even preoperatively, in patients with T3 and T4 tumors, while additional deterioration of speech function occurred postoperatively. When comparing reconstruction techniques, use of local grafts showed less postoperative deterioration in the patients with T3 and T4 tumors (expert rating/student rating -5.0% +/- (-3.8%), whereas impairment was much more evident when jejunal flaps (expert rating/student rating -27.9% +/- (-35.1%) and myocutaneous and faciocutaneous flaps (expert rating/student rating -34.2% +/- (-48.1%) were used. Results demonstrated that patients should be informed about negative side effects following radical tumor resections and reconstructions of large tissue defects. Surgery should avoid marked motor and sensory nerve lesions whenever possible. Before speech therapy is begun, speech function should be examined carefully. Speech intelligibility should also be documented, e.g. with audio tapes, for quality assessment.