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Biomedical subjects

F L Wuyts

Publications and source records attributed to F L Wuyts.

At least 19 recordsLinked to original sources

Relevance of subglottic pressure in normal and dysphonic subjects.

The purpose of this study was to determine the clinical value of subglottic pressure (SGP) in normal and dysphonic subjects. "The airway interrupted method" was used to measure the intra-oral pressure. Voice samples from 60 healthy subjects and 79 dysphonic patients were recorded under normal conditions of pitch and intensity. In normal subjects, age and gender have no significant impact on mean and peak SGP. The peak SGP measurements are significantly higher in dysphonic patients and could be included in the basic clinical set of objective voice parameters. No differences could be shown between pre- and postoperative assessments or between groups of dysphonic patients.

Adolescent↗

Evolution of vocal fold nodules from childhood to adolescence.

SUMMARY: Bilateral (quasi) symmetrical lesions of the anterior third of the vocal folds, commonly called vocal fold nodules (VFNs) are the most frequent vocal fold lesions in childhood caused by vocal abuse and hyperfunction. This study evaluates their long-term genesis with or without surgery and voice therapy. A group of 91 postmutational adolescents (mean age, 16 years), in whom VFNs were diagnosed in childhood, were questioned to analyze the evolution of their complaints. Thirty four of them could be clinically reexamined by means of the European Laryngological Society-protocol, including a complete laryngological investigation and voice assessment. A total of 21% of the questioned group (n=91) had voice complaints persisting into postpubescence with a statistically significant difference (P <or= 0.001) between boys (8%) and girls (37%). VFNs were still present in 47% of the girls and 7% of the boys of the clinically evaluated group (n=34). Analysis of the data before and after puberty shows that the variables gender, allergy, and degree of dysphonia ("G") in childhood enable a fairly correct prediction of persisting voice complaints in adolescence (sensitivity of 89% and specificity of 67%). The results of this study show a clearly different evolution for both sexes, with significant higher long-term risks for dysphonic girls with allergy.

Adolescent↗

Validity of a new feedback method for the VEMP test.

CONCLUSIONS: We used a feedback method, based on a blood pressure manometer with inflatable cuff, to control the sternocleidomastoid muscle (SCM) contraction. To obtain comparable left-right VEMP responses, it is necessary (1) to determine which cuff pressures on both sides yield identical mean rectified voltage (MRV) values of the SCM contraction and (2) to apply these cuff pressures during the VEMP test. OBJECTIVE: To investigate the effect of the SCM muscle contraction variability on the VEMP variables when applying the feedback method. MATERIALS AND METHODS: Subjects pushed with their jaw against the hand-held inflated cuff to generate cuff pressures of subsequently 30, 40 and 50 mmHg during a MRV and VEMP measurement. RESULTS: When analyzing the relationship between the applied cuff pressures and the MRV values/VEMP amplitudes, we showed that (1) there was a linear relationship, (2) there was no side effect and (3) there was an interaction effect between 'side' and 'subject'. There was neither a side effect, nor an effect of the applied cuff pressure when considering the p13 latencies. As for the n23 values, there was no side effect but there was a significant difference when comparing the n23 latencies at cuff pressures of 30 vs 40 mmHg/50 mmHg.

Acoustic Stimulation↗

Good speech recognition and quality-of-life scores after cochlear implantation in patients with DFNA9.

OBJECTIVE: To compare audiometric and quality-of-life results in DFNA 9 patients who received a cochlear implant with cochlear implant patients with adult-onset progressive sensorineural hearing loss. STUDY DESIGN: Prospective comparative design; results were collected cross-sectionally. SETTING: Tertiary referral center. PATIENTS: Eleven DFNA 9 patients were included in the study as well as a comparative group of 39 post-lingually deafened cochlear implant subjects with adult-onset progressive sensorineural hearing loss. INTERVENTIONS: All patients received a cochlear implant. Subjects were implanted with either the Nucleus 24 M/RCS or Med-el Combi 40+ cochlear implant systems implementing the SPEAK, ACE, or CIS+ coding strategies. MEAN OUTCOME MEASURES: Speech recognition was determined by means of phonetically balanced monosyllabic word lists. The Hearing Handicap Inventory for Adults, the Glasgow Benefit Inventory, and the Scale for the Prediction of Hearing Disability in Sensorineural Hearing Loss were used to quantify the quality of life. RESULTS: The results show that the speech perception and the quality of life of the DFNA 9 patients do not differ significantly from the control group (p=0.179; p=0.56). CONCLUSION: In spite of the fact that DFNA 9 is a disease that is known to involve cochlear dendrites, cochlear implantation is a good option for treatment of deafness in DFNA 9.

Adult↗

Posterior semicircular canal dehiscence: value of VEMP and multidetector CT.

OBJECTIVE: To illustrate that posterior semicircular canal dehiscence can present similarly to superior semicircular canal dehiscence. CASE STUDY: The symptomatology initially presented as probable Menière's disease evolving into a mixed conductive hearing loss with a Carhart notch-type perceptive component suggestive of otosclerosis-type stapes fixation. A small hole stapedotomy resulted in a dead ear and a horizontal semicircular canal hypofunction. Recurrent incapacitating vertigo attacks developed. Vestibular evoked myogenic potential (VEMP) testing demonstrated intact vestibulocollic reflexes. Additional evaluation with high resolution multidetector computed tomography (MDCT) of the temporal bone showed a dehiscence of the left posterior semicircular canal. CONCLUSIONS: Besides superior semicircular canal dehiscence, posterior semicircular canal dehiscence has to be included in the differential diagnosis of atypical Menière's disease and/or low tone conductive hearing loss. The value of performing MDCT before otosclerosis-type surgery is stressed. VEMP might contribute to establishing the differential diagnosis.

Adult↗

Meniett therapy: rescue treatment in severe drug-resistant Ménière's disease?

CONCLUSION: Our data indicate that Meniett therapy is unlikely to be helpful in the long-term treatment of patients with severe, drug-resistant Ménière's disease (MD) in whom injection of intratympanic gentamicin (ITG) or another destructive procedure would otherwise be performed. OBJECTIVE: To investigate the value of Meniett therapy in patients with drug-resistant MD referred for injection of ITG. MATERIAL AND METHODS: Twelve patients referred for ITG treatment were followed during a 2-month period of Meniett therapy. Symptoms, functional level and hearing status were evaluated using a standardized staging system. Disease-specific quality-of-life measures were obtained before and after Meniett therapy. At the end of the study period, patients were followed for a mean of 37 months, thus providing long-term outcome data. RESULTS: In two patients, Meniett treatment was interrupted after 1 month because of persistent severe vertigo. In the remaining 10 subjects, we found a significant decrease in the median number of vertigo spells from 10.0/month (25th-75th percentile 4.0-19.0) prior to treatment to 3.0/month (25th-75th percentile 1.5-4.5) after treatment (p = 0.02). There was, however, no improvement in hearing status, tinnitus, functional level or self-perceived dizziness handicap. Long-term (>1 year) follow-up data revealed that only 2 subjects preferred to continue Meniett therapy and that ablative surgery had to be performed in 6/12 study patients.

Adult↗

Target-controlled infusion of rocuronium in infants, children, and adults: a comparison of the pharmacokinetic and pharmacodynamic relationship.

UNLABELLED: Target-controlled infusion (TCI) of rocuronium can be used to maintain a stable blood concentration (Cp). At steady-state, the pharmacokinetics (PK) are compensated for by TCI, and a stable effect can be observed. The theoretical Cp may represent effect-site concentration (EC). We used the EC-effect relationship to study pharmacodynamics (PD) in infants, children, and adults. After giving their written, informed consent, 14 infants, 23 children, and 21 adults scheduled for elective surgical procedures received 3 to 6 ascending Cp targets of TCI rocuronium according to PD data. Just before each increase of TCI, venous blood samples were taken to measure Cp. Neuromuscular block was evaluated acceleromyographically. Individual effect data and measured Cp were fitted to the Hill equation. Maximum block during TCI targets-1000, 1300, and 1600 ng/mL-was smaller in children in comparison with infants and adults. The concentration in the effect compartment associated with a 50% drug effect (EC(50)) was significantly smaller in infants (mean [SD]) (652 [215] ng/mL) than in adults (954 [276] ng/mL) and was the largest in children (1200 [295] ng/mL). Calculated mean EC(90) values were 1705, 2230, and 2035 ng/mL, respectively, in infants, children, and adults. TCI rocuronium established steady-state PK/PD at different TCI targets and allowed us to define PK/PD relationships in a standardized way. Steady-state TCI rocuronium revealed the most potency of rocuronium in infants and the least in children. IMPLICATIONS: Target-controlled infusion (TCI) of rocuronium in infants, children, and adults was used to analyze the pharmacokinetic/pharmacodynamic relationship. Steady-state TCI rocuronium revealed the most potency of rocuronium in infants and the least in children.

Adolescent↗

Arthroscopic subacromial decompression for advanced (stage II) impingement syndrome: a study of 52 patients with five years follow-up.

The authors report a prospective five-year follow-up study of 52 patients who had arthroscopic subacromial decompression for advanced (stage II: type 1 and 2) rotator cuff disease. All patients were assessed preoperatively, at six months and at five years postoperatively using the Constant-Murley score and the revised American Shoulder and Elbow Surgeons (ASES) score. From six months until five years postoperatively, 45 (out of 52) patients showed a further progressing improvement and relief of symptoms. This is established by a significant (p < 0.001) increase of the mean Constant-Murley score from 76.4 at six months postoperatively to 84.9 at five years postoperatively.

Adult↗

Normative voice range profiles of male and female professional voice users.

Normative voice range profiles (VRP) are calculated for a group of male and female teachers, based on 43 and 46 recordings, respectively. All individuals had healthy voices. These normative VRPs contain 95% prediction intervals for both frequency and intensity. They are based on a series of mathematical transformations of the original individual VRPs in order to maintain in the normative VRPs the typical oval VRP shape, including the dip between modal and falsetto register. The normative VRPs presented are directly applicable in the clinical practice of otolaryngologists and speech-language pathologists.

Adult↗

Poor voice quality in future elite vocal performers and professional voice users.

The voice quality of 86 occupational voice users, i.e., students of a high school for audiovisual communication, was assessed by means of a multidimensional test battery containing: the GRBAS scale, videolaryngostroboscopy, maximum phonation time, jitter, lowest intensity, highest frequency, dysphonia severity index (DSI), and voice handicap index (VHI). In a questionnaire on daily habits the prevalence of smoking, eating habits, and vocal abuse were recorded. A comparison of the voice characteristics of the future occupational voice users with a control group revealed significant differences. The results of the VHI and the DSI of these students revealed significantly worse scores than the score of a control group characterized by no vocal complaints. Moreover, the questionnaire on daily habits showed that the future elite vocal performers and professional voice users take less precautions for the care of their voices. These findings support the importance of a good balanced vocal coaching.

Adolescent↗

MR features of peripheral nerve sheath tumors: can a calculated index compete with radiologist's experience?

The aims of this study were, firstly, to provide a formula (neurogenic index) based on MR characteristics used in daily routine for predicting whether a soft tissue tumor is neurogenic or not, secondly, to test prospectively the performance of this formula, and thirdly, to compare this performance with that of radiologists experienced in MR imaging of soft tissue tumors. Retrospectively, MR images of 70 neurogenic and 70 non-neurogenic soft tissue tumors were evaluated in random order by two teams of two observers each. A neurogenic index (NI) was calculated based on those MR parameters that showed no or minor interobserver variability. Subsequently, three investigators in concert used the NI in a validation group of 15 neurogenic and 22 nonneurogenic soft tissue tumors. The same team, based on their own experience, tried to differentiate in the same validation group neurogenic from non-neurogenic soft tissue tumors. This was expressed in a subjective score (SS). Sensitivity, specificity, and predictive values were calculated. NI comprised spread (intra- or extracompartmental), distribution, fluid-fluid levels, homogeneity on T2-weighted images (WI), highest signal intensity (SI) on T1WI, lowest SI on T2WI, and delineation on T2WI. In the validation group, NI had a sensitivity of 88.6%, a specificity of 52.0%, a positive predictive value (PPV) of 54.1%, and a negative predictive value (NPV) of 84.6% for neurogenic tumors. The subjective score SS was superior and had a sensitivity of 93.3%, a specificity of 77.2%, a PPV of 73.7%, and a NPV of 94.4%. Our NI was less accurate than the SS; however, the low number of false-negative diagnoses for neurogenic tumors warrants continued efforts in development of neural networks.

Adolescent↗

Rate influences on tone burst summating potential amplitude in electrocochleography: clinical(a) and experimental(b) data.

Electrocochleographic recordings of action and summating potentials are widely used in the electrophysiological assessment of endolymphatic hydrops (ELH). Increased amplitudes of the summating potential (SP) in response to tone burst stimuli are indicative of positive ELH. This study reports the effect of repetition rate of tone burst stimulation on the SP amplitude. Using transtympanic electrocochleography (ECochG), the SP in response to 1 kHz tone bursts was recorded in both a Ménière and a non-Ménière population. Absolute values of the SP were systematically higher in the Ménière group. Moreover, in the Ménière and non-Ménière groups, the response amplitudes of the SP at a repetition rate of 8.4 tone bursts/s were only 66 and 32%, respectively, of the maximal response amplitude which was obtained at the rate of 37.4 tone bursts/s. Additionally, in normal guinea pigs chronically implanted with a round window electrode, the SP was recorded to 0.5-16 kHz tone burst stimulations presented at 100 dB SPL with the same different repetition rates. Similar enhancement of the SP amplitude was observed from 8.4 to 37.4 stimuli/s, whatever the frequency. This effect is interpreted as an increased asymmetry of vibration of the cochlear partition, whose mechanical operating point would not return to the normal resting position at high repetition rates, since it is permanently shifted in ELH.

Acoustic Stimulation↗

Otolith function after acoustic neuroma surgery.

The response of the vestibular system after acoustic neuroma surgery was investigated in nine patients. The otolith system was studied by means of ocular counterrolling, assessed by video oculography. Horizontal vestibulo-ocular reflex (VOR) function was tested by the sinusoidal harmonic acceleration test using electronystagmography. The results were compared with those obtained from a normal control population. The response to slow rotation tests was symmetric, but the gain was significantly reduced when compared to the normal population. Phase lag was significantly increased. No difference in ocular torsion was observed with lateroflexion of the head to the ipsilateral side in comparison with lateroflexion to the contralateral side. Moreover, the overall ocular counterrolling was well within normal limits. We conclude that the semicircular canal response differs from the otolith response. The component of the torsional VOR mediated by otolith stimulation appears to be more robust than the horizontal VOR mediated mainly by the horizontal semicircular canal system. Ocular counterrolling induced by lateroflexion does not reveal abnormalities in patients with surgically produced unilateral peripheral loss.

Adult↗

Hereditary otovestibular dysfunction and Ménière's disease in a large Belgian family is caused by a missense mutation in the COCH gene.

OBJECTIVE: To report the clinical, auditory, and vestibular characteristics of a nonsyndromic otovestibular dysfunction in a large Belgian family caused by a missense mutation of the DFNA9 gene: COCH. STUDY DESIGN: Retrospective study of the clinical, audiologic, and vestibular data of 60 genetically affected cases. SETTING: Tertiary referral center. PATIENTS: All members of a Belgian kindred who carry the genetic (P51S) defect linked to the inherited hearing and vestibular impairment. INTERVENTIONS: Diagnostic otologic, audiometric, and vestibular analysis and imaging. MAIN OUTCOME MEASURES: Pure tone audiometry, supraliminary audiometry. and vestibular investigation. RESULTS: The autosomal dominant inherited impairment was characterized by peripheral degeneration of the inner ear, leading to total deafness and bilateral vestibular areflexia. CONCLUSIONS: The genetically affected persons of a Belgian family shared a progressive sensorineural hearing loss starting between the third and sixth decade. Vestibular symptoms started at about the same age as the hearing loss. The vestibular symptoms consisted of instability in darkness, a tendency to fall sideways, light-headiness, a drunken feeling, and attacks of vertigo. Most of the patients reported tinnitus, and half of them reported pressure in the ears. Clinically, 9 of the 60 patients met the criteria for definite Ménière's disease, and another 13 and 17 patients met the criteria for probable or possible Ménière's disease, respectively. All 9 were older than the age of 35, but only 1 was older than 55 years, so more than 30% of the patients were between 35 and 55 years old. A specific pattern could be recognized in the evolution of the otovestibular impairment. Under the age of 35 years, almost all the affected family members had normal hearing, whereas above the age of 55 years, the hearing loss was at least moderate, and vestibular hypofunction occurred. In between, there was a transition period of two to three decades, when deterioration of the cochleovestibular function occurred, with a temporary audiometric and vestibular asymmetry.

Adult↗

Nasometric values for normal nasal resonance in the speech of young Flemish adults.

OBJECTIVE: The purpose of this study was to obtain normative nasalance scores for adult subjects speaking the Flemish language. Additional objectives of the study were to determine if speaker sex played a role in differences in nasalance scores and if significantly different nasalance scores existed for Flemish compared with other languages or dialects. DESIGN: Nasalance scores were obtained while young Flemish adults read three standard nasalance passages. These passages were an oronasal passage (a text that contained the same approximate percentage of nasal consonants as found in the standard Dutch speech), an oral passage (a text that excluded nasal consonants), and a nasal passage (a reading text loaded with nasal consonants). PARTICIPANTS: Subjects included 58 healthy young Flemish adults with normal oral and velopharyngeal structure and function, normal hearing levels, normal voice characteristics, and normal resonance and articulation skills. METHODS: The Nasometer (model 6200) was used to obtain nasalance scores for the three reading passages. These three reading passages were designed specifically for use with the nasometer. The nasalance data were analyzed for sex dependence, using Student's t test for each reading passage. This same test was used for comparison of our data with data of other languages. RESULTS: Normative nasalance data were obtained for the oronasal text (33.8%), the oral text (10.9%), and the nasal text (55.8%). Female speakers exhibited significantly higher nasalance scores than male speakers on the passages containing nasal consonants (normal text, p = .001; nasal text, p = .042). Furthermore, statistically significant cross-linguistic nasality differences were observed. The English and Spanish languages were found to have more nasalance than the Flemish language. For the North Dutch and Flemish languages, this cross-linguistic phenomenon was absent. CONCLUSION: These normative nasalance scores for normal young adults speaking the Flemish language provide important reference information for Flemish cleft palate teams. Sex-related differences and cross-linguistic differences were shown.

Adult↗

Accuracy of computer navigation in ear, nose, throat surgery: the influence of matching strategy.

OBJECTIVE: To measure the effect of 4 different matching strategies on the accuracy of computer navigation on the face and within the nose and rhinopharynx. DESIGN: Survey. SETTING: Laboratory study. SUBJECTS: Six human cadavers studied within 24 hours of death. INTERVENTIONS: A commercially available navigation system with infrared optical tracking was used for computer navigation on the face and within the nose of the subjects after matching with external fiducials or with 3 different configurations of anatomical landmarks. Navigation errors were measured and correlated to matching strategies and compared through statistical analysis. RESULTS: Matching with external fiducials on the face results in smaller navigation error than matching with anatomical landmarks. The configuration of matching strategies with anatomical landmarks also significantly determines the accuracy of computer navigation, especially when different locations of accuracy measurement are considered. CONCLUSION: Statistically significant findings have shown that the choice of a matching strategy is a major factor in the accuracy of computer navigation for ear, nose, throat surgery. Arch Otolaryngol Head Neck Surg. 2000;126:1462-1466

Cadaver↗