Air pulse deformation measurement: a preliminary method for noninvasive vocal fold pliability analysis.

OBJECTIVE: A new method, air pulse pliability measurement, is presented, with which the pliability and elasticity of the vocal folds was measured in vitro and in vivo using air pulses. The size of the mucosal movements induced by air pulse stimulation was measured with a laser-based technique. SUBJECTS AND METHODS: The air pulses fed via a 2-mm tubing, introduced through the working channel of a flexible endoscope. Both in vitro and in vivo tests were performed. Nine normal, vocally healthy subjects were examined by air pulse stimulations of the vocal folds, of the skin (cheek and dorsum of the hand) and of the inside of the lips. RESULTS: The in vitro tests showed a coefficient of variation of 5% within a range of 1-5 mm from the probe to the surface. The elasticity data showed no differences between vocal folds, lips or cheek. The hand data showed a significantly higher stiffness as compared to the other 3 measuring points (p < 0.001). The coefficient of variation was about 35% for all measuring points, but in ideal conditions on skin it was 9%. CONCLUSION: The results show that the technique allows automatic, quantitative, noninvasive vocal fold pliability measurements on awake subjects.

Mode of delivery modulates physiological and behavioral responses to neonatal pain.

OBJECTIVE: To study whether the mode of delivery alters pain expression. STUDY DESIGN: Full-term infants born by vaginal delivery or elective caesarean section were observed following high- and low-intensity pain stimuli, with recording of electrocardiogram, facial expression and vocalization. RESULT: Graded physiological and behavioral responses occurred, with greater responses to higher than lower intensity pain stimuli. Elevation in heart rate following both stimuli increased with time after vaginal delivery. Infants delivered by elective caesarean section showed stronger facial expressions and briefer time in vocalizations response to both interventions. CONCLUSION: Diminished responses following vaginal delivery suggest that physiological events associated with a normal delivery reduce the physiologic and sympathoadrenal activation by nociceptive mechanisms. Pain and stress reactivity appear to be inhibited during fetal life and sensory inputs during vaginal delivery may reverse this inhibition. To minimize neonatal pain, we recommend that postnatal invasive procedures to be performed shortly after vaginal birth.

Laser Doppler measurements of the vocal fold blood micro-circulation.

The authors have developed a laser Doppler method, referred to as LDF+LS (laser Doppler flowmetry by laryngostereometry), for measuring the vocal fold micro-circulation. The vocal folds of 103 patients were examined during general anesthesia. A laser Doppler probe was placed on defined positions at the vocal fold edge: midmembranous position (MP), 2 mm and 4 mm behind, and 1 mm anterior to MP. Three parameters were derived, ie, the concentration (CMBC) and velocity (V) of moving blood cells, and the product of both resulting in perfusion: P = CMBCxV. The results of 53 subjects with normal vocal fold status showed that the V at MP was significantly lower than 2 mm behind MP (P < 0.05). Men had significantly higher velocity than women (P < 0.05). Subjects older than 65 years had higher perfusion and CMBC as compared with younger subjects (P < 0.01). Smokers with normal vocal folds had higher velocity than non-smokers (P < 0.05). Measurements of healthy vocal folds were compared with benign vocal fold pathology. Vocal fold polyps had significantly higher perfusion than normal vocal folds (P < 0.01). In conclusion, the laser Doppler measurement is a sensitive tool estimating superficial blood flow in both normal and pathological vocal folds. The blood flow in normals differs with respect to gender and age probably due to variations in micro-circulation of the mucosa and lamina propria. Vocal fold pathology and external factors such as smoking result in blood flow changes.

Viscoelastic and histologic properties in scarred rabbit vocal folds after mesenchymal stem cell injection.

OBJECTIVE/HYPOTHESIS: The aim of this study was to analyze the short-term viscoelastic and histologic properties of scarred rabbit vocal folds after injection of human mesenchymal stem cells (MSC) as well as the degree of MSC survival. Because MSCs are antiinflammatory and regenerate mesenchymal tissues, can MSC injection reduce vocal fold scarring after injury? STUDY DESIGN: Twelve vocal folds from 10 New Zealand rabbits were scarred by a localized resection and injected with human MSC or saline. Eight vocal folds were left as controls. MATERIAL AND METHODS: After 4 weeks, 10 larynges were stained for histology and evaluation of the lamina propria thickness. Collagen type I content was analyzed from six rabbits. MSC survival was analyzed by fluorescent in situ hybridization staining from three rabbits. Viscoelasticity for 10 vocal folds was analyzed in a parallel-plate rheometer. RESULTS: The rheometry on fresh-frozen samples showed decreased dynamic viscosity and lower elastic modulus (P<.01) in the scarred samples injected with MSC as compared with the untreated scarred group. Normal controls had lower dynamic viscosity and elastic modulus as compared with the scarred untreated and treated vocal folds (P<.01). Histologic analysis showed a higher content of collagen type 1 in the scarred samples as compared with the normal vocal folds and with the scarred folds treated with MSC. MSCs remained in all samples analyzed. CONCLUSIONS: The treated scarred vocal folds showed persistent MSC. Injection of scarred rabbit vocal folds with MSC rendered improved viscoelastic parameters and less signs of scarring expressed as collagen content in comparison to the untreated scarred vocal folds.

Viscoelastic measurements after vocal fold scarring in rabbits--short-term results after hyaluronan injection.

CONCLUSIONS: The scarring model resulted in significant damage and elevated viscoelasticity of the lamina propria. Hyaluronan preparations may alter viscoelasticity in scarred rabbit vocal folds. OBJECTIVES: Vocal fold scarring results in stiffness of the lamina propria and severe voice problems. The aims of this study were to examine the degree of scarring achieved in the experiment and to measure the viscoelastic properties after injection of hyaluronan in rabbit vocal folds. MATERIALS AND METHODS: Twenty-two vocal folds from 15 New Zealand rabbits were scarred, 8 vocal folds were controls. After 8 weeks 12 of the scarred vocal folds received injections with 2 types of cross-linked hyaluronan products and 10 scarred folds were injected with saline. After 11 more weeks the animals were sacrificed. After dissection, 15 vocal folds were frozen for viscoelastic measurements, whereas 14 vocal folds were prepared and stained. Measurements were made of the lamina propria thickness. Viscoelasticity was measured on intact vocal folds with a linear skin rheometer (LSR) adapted to laryngeal measurements. RESULTS: Measurements on the digitized slides showed a thickened lamina propria in the scarred samples as compared with the normal vocal folds (p<0.05). The viscoelastic analysis showed a tendency to stiffening of the scarred vocal folds as compared with the normal controls (p=0.05). There was large variation in stiffness between the two injected hyaluronan products.

Pharyngeal and laryngeal symptoms and signs related to extraesophageal reflux in patients with heartburn in gastroenterology practice: a prospective study.

OBJECTIVES: To describe pharyngeal and laryngeal symptoms and findings in correlation to extraesophageal reflux (EER) in patients with heartburn. DESIGN: A prospective study. SETTING: Patients referred to Department of Gastroenterology, Karolinska University Hospital Huddinge. PARTICIPANTS: Forty-three patients with chronic heartburn as the primary symptom, subdivided on the basis of oesophageal manometry to have gastro-oesophageal reflux disease (GORD) (n = 25) or not (n = 18). MAIN OUTCOME MEASURES: Laryngeal video recordings of 43 patients were examined off-line. The occurrence of symptoms and laryngeal pathology were correlated to the results of 24-h double-probe pH monitoring. RESULTS: Pharyngeal or laryngeal symptoms occurred often or quite often in 72% (18 of 25) of the GORD patients and 61% (11 of 18) of the patients without GORD. EER occurred in 73% (16 of 22) of the GORD patients with laryngeal symptoms and in 38% (6 of 16) of those without GORD but with laryngeal symptoms (P = 0.047). In the multivariate analysis the odds for hoarseness was 17 times higher if the patient had heartburn more than five times a day, compared with patients with heartburn less than once a day (OR 17.8, CI 1.7-405.9; P = 0.01). Cohen's kappa for intrarater reliability was 0.851 (P = 0.001). Laryngeal pathology was found in 56% of the GORD patients and 44% patients without GORD. There was no significant difference in the occurrence of any specific symptom or finding between the patients with and without GORD, nor with and without EER. CONCLUSIONS: Although GORD together with laryngeal symptoms seem to be predictive of EER, there are no specific pharyngeal and laryngeal symptoms or findings that would help distinguishing patients with EER from those without. However, the more frequent the heartburn to the more frequent is hoarseness.

Is pseudosulcus alone a reliable sign of gastroesophago-pharyngeal reflux?

To investigate if laryngeal pseudosulcus (bilateral infraglottic oedema) is a reliable sign of pharyngeal reflux, the video recordings of 59 patients and 18 controls were examined off-line by two phoniatricians. Eleven video segments were duplicated for calculation of intrarater reliability. The frequency of pseudosulcus was correlated to the results of 24-h double-probe pH monitoring. The intrarater reliability was moderate (K = 0.582; P = 0.005). The sensitivity of pseudosulcus in the diagnosis of pharyngeal reflux among the patients was 30% and among the controls it was 0%. The positive predictive value (PPV) of pseudosulcus for patients with pharyngeal and laryngeal symptoms was 67%, while for the controls it was 0%. The negative predictive value (NPV) of pseudosulcus for patients with pharyngeal or laryngeal symptoms was 32% and for the controls it was 64%. The single finding of pseudosulcus is not a very sensitive predictor of pharyngeal reflux but if the patient has laryngeal symptoms and a pseudsulcus, the probability that the patient has pharyngeal reflux is almost 70%.

Vibratory capacity and voice outcome in patients with scarred vocal folds treated with collagen injections--case studies.

This prospective case study evaluates the effect of collagen injections on vibratory capacity and voice outcome in four patients with vocal fold scarring. The minimum follow-up time was 6 months. We studied the effect of the injections on the vibratory capacity in a multidimensional way, using computerized image analysis of videostroboscopy, acoustic and perceptual analysis of voice recordings, as well as patients' self-evaluations. Subjective voice ratings from the patients showed improvement in two patients, while two patients had no change in voice function. None of the patients experienced any side effects from the treatment. The documented acoustic and perceptual changes were marginal, but the videostroboscopic findings suggest some improvement in vibratory capacity.

Leakage around voice prosthesis in laryngectomees: treatment with local GM-CSF.

OBJECTIVES: The aim of this study was to investigate the possibility of treating leakage around voice prosthesis by local injection of granulocyte-macrophage colony-stimulating factor (GM-CSF). STUDY DESIGN: Three patients with nonhealing leaking tracheoesophageal (TE) fistula, resistant to common treatment, were treated with local GM-CSF. MATERIAL AND METHODS: Fistula size was measured and photo documented before and after treatment. RESULT: In all three patients, the fistula shrank, and the leakage ceased. No side effects were observed. CONCLUSION: Local injection with GM-CSF seems to be a simple and effective way of decreasing a leaking TE-fistula in laryngectomized patients. A great advantage was that the procedure could be done with the voice prosthesis in place.

Vocal fold vibrations: high-speed imaging, kymography, and acoustic analysis: a preliminary report.

OBJECTIVES: To evaluate a new analysis system, High-Speed Tool Box (H. Larsson, custom-made program for image analysis, version 1.1, Department of Logopedics and Phoniatrics, Huddinge University Hospital, Huddinge, Sweden, 1998) for studying vocal fold vibrations using a high-speed camera and to relate findings from these analyses to sound characteristics. STUDY DESIGN: A Weinberger Speedcam + 500 system (Weinberger AG, Dietikon, Switzerland) was used with a frame rate of 1,904 frames per second. Images were stored and analyzed digitally. Analysis included automatic glottal edge detection and calculation of glottal area variations, as well as kymography. These signals were compared with acoustic waveforms using the Soundswell program (Hitech Development AB, Stockholm, Sweden). METHODS: The High-Speed Tool Box was applied on two types of high-speed recordings: a diplophonic phonation and a tremor voice. Relations between glottal vibratory patterns and the sound waveform were analyzed. RESULTS: In the diplophonic phonation, the glottal area waveform, as well as the kymogram, showed a specific pattern of repetitive glottal closures, which was also seen in the acoustic waveform. In the tremor voice, fundamental frequency (F0) fluctuations in the acoustic waveform were reflected in slow variations in amplitude in the glottal area waveform. For studying details of mucosal movements during these kinds of abnormal vibrations, the glottal area waveform was particularly useful. CONCLUSIONS: Our results suggest that this combined high-speed acoustic-kymographic analysis package is a promising aid for separating and specifying different voice qualities such as diplophonia and voice tremor. Apart from clinical use, this finding should be of help for specification of the terminology of different voice qualities.

[Fiberoptic endoscopy confirms the cause of upper respiratory obstruction in small children. The most common causes to referrals are sleep apnea syndrome and inspiratory stridor]. / Fiberskopi fastställer orsak till höga andningshinder hos små barn. Vanligaste remissorsakerna sömnapnésyndrom och inspiratorisk stridor.

Guidelines for the clinical investigation of young children with stridor and sleep apnea are presented. Clinical examination and flexible videolaryngoscopy performed in local anaesthesia are the most important diagnostic tools for this group of children. If the impairment is severe or an objective evaluation is needed the child should also undergo nocturnal polygraphic recording and lung function tests. Out of 43 children examined with flexible videolaryngoscopy 21 had positive findings, laryngomalacia being the most common diagnosis. Flexible videolaryngoscopy is a good complement to laryngoscopy under general anaesthesia. It can be performed as early as in the neonatal period.

Botulinum toxin injections for essential voice tremor.

Fifteen patients, 13 women and 2 men, with a mean age of 72.7 years (56 to 86 years) and a clinical diagnosis of essential voice tremor, were treated with botulinum injections to the thyroarytenoid muscles, and in some cases, to the cricothyroid or thyrohyoid muscles. Evaluations were based on subjective judgments by the patients, and on perceptual and acoustic analysis of voice recordings. Subjective evaluations indicated that the treatment had a beneficial effect in 67% of the patients. Perceptual evaluations showed a significant decrease in voice tremor during connected speech (p < .05). Acoustic analysis showed a nearly significant decrease in the fundamental frequency variations (p = .06) and a significant decrease in fundamental frequency during sustained vowel phonation (p < .01 ). The results of perceptual evaluation coincided most closely with the subjective judgments. It was concluded that the treatment was successful in 50% to 65% of the patients, depending on the method of evaluation.

A comparison of subglottal and intraoral pressure measurements during phonation.

Intraoral pressure and subglottal pressure, derived from tracheal puncture, were recorded with the electroglottographic signal for one normal speaking male during phonation. The mean subglottal pressure for vowels was also estimated by interpolating the intraoral pressure from surrounding /p/occlusions. The pressure measurements were highly correlated (r = 0.98) and there were small pressure value differences (on average < 2%). The effects of varying speech rate and mode of phonation on the pressure measurements are discussed. A decrease in pressure from the mean subglottal pressure for the open phase and an increase for the closed phase was found during the glottal vibratory cycles.

Glottal closure, transglottal airflow, and voice quality in healthy middle-aged women.

Seventeen healthy women, 45 to 61 years old, were examined using videofiberstroboscopy during phonation at three loudness levels. Two phoniatricians evaluated glottal closure using category and ratio scales. Transglottal airflow was studied by inverse filtering of the oral airflow signal recorded in a flow mask (Glottal Enterprises System) during the spoken phrase /ba:pa:pa:pa:p/ at three loudness levels. Subglottal pressure was estimated from the intraoral pressure during p occlusion. Running speech and the repeated /pa:/ syllables were perceptually evaluated by three speech pathologists regarding breathiness, hypo-, and hyperfunction, using continuous scales. Incomplete glottal closure was found in 35 of 46 phonations (76%). The degree of glottal closure increased significantly with raised loudness. Half of the women closed the glottis completely during loud phonation. Posterior glottal chink (PGC) was the most common gap configuration and was found in 28 of 46 phonations (61%). One third of the PGCs were in the cartilaginous glottis (PGCc) only. Two thirds extended into the membranous portion (PGCm); most of these occurred during soft phonation. Peak flow, peak-to-peak (AC) flow, and the maximum rate of change for the flow in the closing phase increased significantly with raised loudness. Minimum flow decreased significantly from normal to loud voice. Breathiness decreased with increased loudness. The results suggest that the incomplete closure patterns PGCc and PGCm during soft phonation ought primarily to be regarded as normal for Swedish women in this age group.

Glottal area and vibratory patterns studied with simultaneous stroboscopy, flow glottography, and electroglottography.

The purpose of the present study was to examine the relationship between variations in glottal area and vibratory patterns during phonation studied with stroboscopy and glottographic methods. Two normal speaking male and three female subjects were examined by means of simultaneous stroboscopy, flow glottography, and electroglottography. Estimations were made of the glottal area from pressure and flow data using the formula described by van den Berg. Significant correlations were found for the male phonations between estimations and measurements of the minimum glottal area (glottal insufficiency). Estimations of the peak glottal area were also significantly correlated to measured peak glottal area for values below 25 mm2. The estimated minimum area tended to be higher, whereas the estimated peak area values were lower than the corresponding glottal area measurements. This might be explained by variations in glottal and supraglottal geometry for different modes of phonation and by sub- and supraglottal acoustic interaction. Several glottographic parameters for the male phonations were highly correlated with the measurements of glottal insufficiency and also differed significantly between normal, pressed, and breathy hypofunctional modes of phonation. The presence of a hump in the first part of the closed phase for the flow glottogram seems to indicate that a clearly visible mucosal wave is present during vocal fold vibration.

Spindle-shaped glottal insufficiency with and without sulcus vocalis: a retrospective study.

The clinical records of 186 patients with spindle-shaped glottal insufficiency were studied in order to evaluate the clinical background of the finding. The patients formed two main groups: those with and those without sulcus vocalis. Most of the sulcus patients were females, comparatively young at the onset of symptoms and at the time of diagnosis. In contrast, the majority of patients with spindle-shaped glottal insufficiency without sulcus were male and they often had a history of either laryngitis or chronic general disease causing decreased physical ability. Some patients in this group had long-standing symptoms, possibly caused by a disturbance in pubertal voice change. The data also indicate differences between the groups in vocal fold vibratory pattern. It is evident that the spindle-shaped glottal insufficiency observed in patients with and without sulcus has different causes and different pathophysiologic explanations.

Vocal dysfunction following cricothyroidotomy: a prospective study.

Voice dysfunction is a known consequence of cricothyroidotomy, but few detailed analyses have been published. This study reports an investigation of voice function in 19 patients who underwent cricothyroidotomy during a 12-month period (54 were patients operated on, 29 survived the primary disease or injury, and 19 agreed to participate in the investigation). The patients were interviewed regarding signs of dysfunction of the cricothyroid muscles, or a diminished external tensor effect on the vocal folds. Laryngoscopy with a magnifying-angled endoscope, stroboscopy, phonetography, determination of mean speaking fundamental frequency, perceptual analysis of the voice, and electromyogram of the cricothyroid muscle were all performed. Four patients had signs of diminished external tensor effect on the vocal folds (mild or moderate voice dysfunction), 5 patients had other voice disorders, and 10 were classified as having normal voice. Elective cricothyroidotomy should be avoided in patients with professional or other activities that place heavy demands on the voice.