Consideration of vocal fold position in unilateral vocal fold paralyses.

The objective of this study was to improve the evaluation of unilateral vocal fold paralyses (uVFP) by means of an area measurement of the glottic plane, which describes the position of the paralysed vocal fold. The area measurements were related to electromyographic findings and clinical outcome (recovery, voice quality). In 56 patients (33 women and 23 men), uVFP were confirmed by endolaryngeal electromyography (EMG) of the paralysed vocal fold and cricothyroid muscles (CT). The EMG response was classified on a 4-point scale (from 0 to 3). Vocal fold position was divided into 'paramedian' and 'intermediate' and additionally quantified by measurement of the glottic area. An 'area quotient' (AQ) was calculated and related to the EMG findings and clinical outcome. Voice qualities were objectified regarding their additive noise (breathiness) and irregularity (roughness) using the 'Göttingen Hoarseness Diagram'. The majority of uVFP was due to iatrogenic lesions. The AQ of classically graduated 'paramedian' and 'intermediate' vocal fold positions was significantly different but did not correlate with objective voice quality values. There were no significant correlations regarding EMG findings, duration or recovery from paralyses. Laryngeal EMG remains the gold standard for verifying uVFP. But EMG did not correlate significantly with AQ or functional outcome of uVFP. The measurement of an AQ is suitable for obtaining continuous data describing the position of paralysed vocal folds beyond the terms 'paramedian' or 'intermediate' and provides the basis for clinical evaluations of diagnostic tools and therapeutic interventions.

Stroboscopy versus high-speed glottography: a comparative study.

OBJECTIVES: To evaluate and to compare the diagnostic value of videostroboscopy (VS) and high-speed glottography (HGG) in dysphonic patients. STUDY DESIGN: Randomized, prospective study. METHODS: A total of 162 patients underwent indirect laryngoscopy using both methods (VS and HGG). The resulting 324 films were evaluated by two professionals (laryngologists, MDs) using a standardized protocol containing established criteria to classify vocal fold vibratory movement qualities. RESULTS: The rating "not assessable" was mentioned significantly more often in VS than in HGG (P < .001). In HGG, methodologic failures were less frequent, and the length of investigation was shorter. Even if the agreement between the two raters was higher in HGG (54%) compared with VS (42%), both percentage values show a low accordance in diagnostic findings. CONCLUSIONS: Regardless of the method used (VS or HGG), perceptive evaluations of vibratory movements of vocal folds revealed a higher variability than assumed. This result supports the need for objective methods to analyze vocal fold vibratory movements. Therefore, real-time imaging of vocal fold vibratory movements using HGG will be necessary.

The supraglottic nerve supply: an anatomic study with clinical implications.

OBJECTIVES: To describe the course of the superior laryngeal nerve (SLN) and its branches, in particular, with regard to supraglottic motor and sensory functions. METHODS: In 30 normal human hemilarynges, the SLN with its internal (intSLN) and external branch (extSLN) were dissected under microsurgical conditions and marked with acrylic dye. All anatomic structures of the larynges (muscles, cartilages, and ligaments) were dissected in detail. RESULTS: The intSLN subdivides into three branches. The superior branch (I) runs to the lingual (extralaryngeal) part of the epiglottis and sends small fibers through the epiglottic foramina to the laryngeal surface. The middle branch (II) runs through the aryepiglottic fold into the ventricular fold, and the inferior branch (III) to the piriform sinus and to the postcricoid region, forming various anastomoses (e.g., ansa galeni) with the recurrent laryngeal nerve (RLN). The extSLN runs to the cricothyroid muscle (CT) and sends a branch through the CT along the lower rim of the thyroid cartilage into the larynx and up to the ventricular fold. This ventricular branch is a potential candidate for the innervation of the ventricular muscle (VM). CONCLUSIONS: Our results may contribute to a better understanding of supraglottic actions that provide primary functions of the larynx (such as swallowing, coughing, and breathing). An enhanced knowledge of neurolaryngology also provides a basis for interpreting disorders or paralyzes following surgical treatments (e.g., thyroid surgery, partial laryngectomy) and helps to lower the risks.

Successful treatment of autophonia with botulinum toxin: case report.

OBJECTIVES: We sought to treat autophonia due to a patulous eustachian tube using botulinum toxin. METHODS: Because we assumed that the patulous eustachian tube was caused by abnormal activity of paratubal muscles (tensor and levator veli palatini muscles and salpingopharyngeus muscle), paralysis was performed via injection of botulinum toxin type A in a 45-year-old female professional musician who had had chronic unilateral autophonia for 20 years. In addition to a patient interview, an endoscopic examination of the nasopharynx (posterior rhinoscopy), ear microscopy, and impedance audiometry were performed to verify the diagnosis and the outcome after treatment. RESULTS: The autophonia disappeared 1 week after treatment. Normalized tympanic ventilation was verified by impedance audiometry after 8 weeks. The period of symptom relief was 9 months. CONCLUSIONS: The administration of botulinum toxin type A provides a new option in the treatment of patulous eustachian tube. The reliability of this method and the effect of repeated injections remains to be proved in future studies.

Predicting mutational change in the speaking voice of boys.

SUMMARY: The authors investigated whether acoustic speaking voice analyses can be used to predict the beginning of mutation in 21 male members of a professional boys' choir. Over a period of 3 years before mutation, children were examined every 3 months by ear, nose, and throat (ENT) and phoniatric specialists. At the same time, the voice was evaluated acoustically using analysis features of the Goettingen Hoarseness Diagram (GHD). Irregularity component and noise component, jitter, shimmer, mean waveform correlation coefficient, and fundamental frequency were determined from recordings of the speaking voice. Significant changes of acoustic features appeared 7 and 5 months before mutation onset, which indicates that vocal function is already restricted 6 months before mutation onset. This acoustic voice analysis is therefore suitable to support the care of the professional singing voice.

Laser microsurgical bilateral posterior cordectomy for the treatment of bilateral vocal fold paralysis.

OBJECTIVES: We performed a prospective study to assess respiratory function and voice quality before and after laser microsurgical bilateral posterior cordectomy performed for chronic airway obstruction in patients with bilateral vocal fold paralysis. METHODS: In 17 patients a laser microsurgical posterior cordectomy was performed as an immediate bilateral approach. Roughness, breathiness, hoarseness, and dyspnea were evaluated both subjectively (on a scale from 0 to 3) and objectively (body plethysmography, computerized voice analysis: Göttingen Hoarseness Diagram). RESULTS: After laser surgery, the patients' respiratory function was significantly increased and was sufficient for all activities of daily living. The body plethysmographic measure of airway resistance had superior descriptive power and correlated significantly with the clinical degree of dyspnea (scale 0 to 3). Pretreatment and posttreatment impairment of voice quality was objectively documented with the Göttingen Hoarseness Diagram; the phonatory results measured with it correlated significantly with the subjective clinical evaluation of hoarseness. Aphonia did not occur. CONCLUSIONS: A bilateral approach for laser microsurgical posterior cordectomy combines excellent airway improvement and satisfactory voice preservation. In bilateral vocal fold paralysis, pretreatment and posttreatment clinical data should be evaluated by objective measures.

Evaluation of Cx26/GJB2 in German hearing impaired persons: mutation spectrum and detection of disequilibrium between M34T (c.101T>C) and -493del10.

Mutations in the connexin 26 gene (GJB2) are responsible for the major part of nonsyndromic autosomal recessive or apparently sporadic prelingual deafness in Caucasians (DFNB1). We screened 228 German hearing-impaired persons for mutations in the GJB2 gene by sequence analysis. Homozygous or compound heterozygous GJB2 mutations were detected in 38/228 (16.7%) of hearing impaired persons. The most frequently occurring mutation was the c.35delG mutation, which was found in 71.1% of the mutated alleles. The next frequent mutation detected in the group of hearing impaired persons was the c.101T>C mutation (9/76 alleles; 11.8%). One new mutation, c.567delA, was observed. We further studied the presence of a 10bp deletion in the 5' UTR of the GJB2 gene (c.-493del10) which was assumed to occur together with the c.101T>C mutation. Ten out of thirteen patients (76.9%) were found to be carriers of both the c.101T>C mutation and the 10bp variant and in 7/14 alleles a linkage disequilibrium between c.101T>C and the 10bp deletion was proven. In 4/14 alleles the linkage was ruled out and for the remaining 3 cases the phase determination was not possible. Seventy one controls were screened for the prevalence of Cx26 mutations and for the c.-493del10 variant. Heterozygosity frequency in the control group was for c.35delG 4.2%, for c.101T>C 1.4% and for c.-493del10 it was 5.6%.

Risk factors of paralysis and functional outcome after recurrent laryngeal nerve monitoring in thyroid surgery.

BACKGROUND: Recurrent laryngeal nerve monitoring (RLNM) has been suspected to reduce postoperative RLN paralysis (RLNP). However, functional outcome of RLNM in comparison with no nerve identification and visual nerve identification only has not been analyzed. METHODS: Analysis of 16,448 consecutive multi-institutional operations resulted in 29,998 nerves at risk. Three groups of different RLN treatment were compared: group 1, no RLN identification; group 2, visual RLN identification; and group 3, visual RLN identification and electromyographic monitoring. RLNM was performed with a bipolar needle electrode that was placed through the cricothyroid ligament into the vocal muscle. RESULTS: Risk factors for permanent RLNP were recurrent benign and malignant goiter (odds ratios, [ORs]), 4.7, and 6.7, respectively), primary surgery in thyroid malignancy (OR, 2.0), lobectomy (OR, 1.8), no nerve identification (OR, 1.4), low or medium volume hospital (OR, 1.3), and low volume surgeons (OR, 1.2). CONCLUSIONS: Based on these data, visual nerve identification was identified to be the gold standard of RLN treatment in thyroid surgery. RLNM is a promising tool for nerve identification and protection in extended thyroid resection procedures. However, because of the overall low frequency of RLNP, no statistical difference compared with visual nerve identification only was reached in the setting of this study.

Human cortical motor representation of the larynx as assessed by transcranial magnetic stimulation (TMS).

OBJECTIVES: To analyze characteristic features and details on motor-evoked potentials (MEPs) of the cricothyroid and vocalis muscles from single-pulse cortical transcranial magnetic stimulation (TMS) in normal subjects to characterize cortical motor representation of laryngeal muscles. STUDY DESIGN: Prospective, experimental investigation on healthy volunteers. METHOD: MEPs of the cricothyroid and vocalis muscles elicited by cortical TMS with a figure-8-shaped coil were investigated in two groups of six healthy subjects each, with special regard to MEP amplitude as a function of the coil position on the head surface along the interaural line. RESULTS: Bilateral reproducible responses of the cricothyroid and the vocalis muscles could be observed in all subjects. For the cricothyroid muscle, maximal responses were obtained at mean stimulus positions of 7.5 +/- 1.4 cm (contralateral) and of 7.3 +/- 1.3 cm (ipsilateral), respectively. For the vocalis muscle, we found maximal responses at mean stimulus positions of 10.3 +/- 1.9 cm (contralateral) and of 9.6 +/- 1.6 cm (ipsilateral), respectively. Despite a considerable overlap of these coil positions, from which reproducible MEPs could be elicited in both groups of the laryngeal muscles, statistically significant separation of the cricothyroid-and vocalis-associated cortical representation areas was possible. CONCLUSIONS: Our observations point to two different cortical motor representation areas, with the cricothyroid muscle-related area being located more medially.

Assessment of irregular voices after total and laser surgical partial laryngectomy.

OBJECTIVES: To assess the merits of computer-aided voice analysis procedures for very irregular voices of patients after total and laser surgical partial laryngectomy, and to characterize qualitative differences in speech and voice function between these 2 groups of patients. DESIGN: Cross-sectional study. SETTING: University hospital in Göttingen, Germany PATIENTS: Twenty-nine patients with advanced laryngeal carcinomas (T3-T4; according to the Union Internationale Contre le Cancer, TNM staging system, stages III-IVa) were examined: 18 patients with tracheoesophageal speech (voice prosthesis) after total laryngectomy and 11 patients who underwent partial transoral resection of the larynx (by means of laser microsurgery without surgical voice rehabilitation). MAIN OUTCOME MEASURES: Speech intelligibility was measured by a standardized and validated telephone test, and voice quality was determined by 2 computerized voice analysis systems (multidimensional voice program and Göttingen hoarseness diagram). RESULTS: The telephone test demonstrated a significantly better speech performance of the patients who had undergone organ-preserving surgery. The voices of both patient groups were too irregular for a qualitative differentiation with the multidimensional voice program. The multidimensional voice program results also failed to show significant correlations to speech intelligibility. The Göttingen hoarseness diagram showed significantly more regular voices in patients with partial laryngectomy than total laryngectomy. These results were correlated with speech intelligibility. CONCLUSIONS: The Göttingen hoarseness diagram is suitable for a qualitative assessment even of irregular voices. Voice prosthesis offers a voice quality that at best approaches that of patients with partial laryngectomy.

Auditory processing disorders with and without central auditory discrimination deficits.

Auditory processing disorder (APD) is defined as a processing deficit in the auditory modality and spans multiple processes. To date, APD diagnosis is mostly based on the utilization of speech material. Adequate nonspeech tests that allow differentiation between an actual central hearing disorder and related disorders such as specific language impairments are still not adequately available. In the present study, 84 children between 6 and 17 years of age (clinical group), referred to three audiological centers for APD diagnosis, were evaluated with standard audiological tests and additional auditory discrimination tests. Latter tests assessed the processing of basic acoustic features at two different stages of the ascending central auditory system: (1) auditory brainstem processing was evaluated by quantifying interaural frequency, level, and signal duration discrimination (interaural tests). (2) Diencephalic/telencephalic processing was assessed by varying the same acoustic parameters (plus signals with sinusoidal amplitude modulation), but presenting the test signals in conjunction with noise pulses to the contralateral ear (dichotic(signal/noise) tests). Data of children in the clinical group were referenced to normative data obtained from more than 300 normally developing healthy school children. The results in the audiological and the discrimination tests diverged widely. Of the 39 children that were diagnosed with APD in the audiological clinic, 30 had deficits in auditory performance. Even more alarming was the fact that of the 45 children with a negative APD diagnosis, 32 showed clear signs of a central hearing deficit. Based on these results, we suggest revising current diagnostic procedure to evaluate APD in order to more clearly differentiate between central auditory processing deficits and higher-order (cognitive and/or language) processing deficits.

Do women's voices provide cues of the likelihood of ovulation? The importance of sampling regime.

The human voice provides a rich source of information about individual attributes such as body size, developmental stability and emotional state. Moreover, there is evidence that female voice characteristics change across the menstrual cycle. A previous study reported that women speak with higher fundamental frequency (F0) in the high-fertility compared to the low-fertility phase. To gain further insights into the mechanisms underlying this variation in perceived attractiveness and the relationship between vocal quality and the timing of ovulation, we combined hormone measurements and acoustic analyses, to characterize voice changes on a day-to-day basis throughout the menstrual cycle. Voice characteristics were measured from free speech as well as sustained vowels. In addition, we asked men to rate vocal attractiveness from selected samples. The free speech samples revealed marginally significant variation in F0 with an increase prior to and a distinct drop during ovulation. Overall variation throughout the cycle, however, precluded unequivocal identification of the period with the highest conception risk. The analysis of vowel samples revealed a significant increase in degree of unvoiceness and noise-to-harmonic ratio during menstruation, possibly related to an increase in tissue water content. Neither estrogen nor progestogen levels predicted the observed changes in acoustic characteristics. The perceptual experiments revealed a preference by males for voice samples recorded during the pre-ovulatory period compared to other periods in the cycle. While overall we confirm earlier findings in that women speak with a higher and more variable fundamental frequency just prior to ovulation, the present study highlights the importance of taking the full range of variation into account before drawing conclusions about the value of these cues for the detection of ovulation.

Cortical sensorimotor control in vocalization: a functional magnetic resonance imaging study.

BACKGROUND: Verbal communication is a human feature and volitional vocalization is its basis. However, little is known regarding the cortical areas involved in human vocalization. METHODS: Therefore, functional magnetic resonance imaging at 3 Tesla was performed in 16 healthy adults to evaluate brain activations related to voice production. The main experiments included tasks involving motor control of laryngeal muscles with and without intonation. In addition, reference mappings of the sensorimotor hand area and the auditory cortices were performed. RESULTS: Related to vocalization, in addition to activation of the most lateral aspect of the primary sensorimotor cortex close to the Sylvian fissure (M1c), we found activations medially (M1a) and laterally (M1b) of the well-known sensorimotor hand area. Moreover, the supplementary motor area and the anterior cingulate cortex were activated. CONCLUSIONS: Although M1a could be ascribed to motor control of breathing, M1b has been associated with laryngeal motor control. Consequently, even though M1c represents a laryngeal sensorimotor area, its exclusiveness as suggested previously could not be confirmed. Activations in the supplementary motor area and anterior cingulate cortex were ascribed to "vocal-motor planning." The present data provide the basis for further functional magnetic resonance imaging studies in patients with neurological laryngeal disorders.

Functional anatomy of the recurrent and superior laryngeal nerve.

BACKGROUND AND AIMS: The purpose of this study was to present the current topographic and anatomical knowledge in neurolaryngology, with special regard to laryngeal paralyses as a major complication in thyroid surgery. PATIENTS AND METHODS: Microscopic anatomical preparation of 22 human hemilarynges was accomplished. RESULTS: Due to their neuroanatomical courses, the following extralaryngeal nerves may be at risk in thyroid surgery: the external branch of the superior laryngeal nerve, the paralaryngeal part of the vagal nerve, the Ansa Galeni, the trunk of the recurrent laryngeal nerve (RLN) and the delicate branches of the RLN to the posterior cricoarytaenoid muscle. The anterior and posterior branches of the RLN (antRLN and postRLN) are less endangered by thyroid surgery because they are covered by the thyroid cartilage and posterior cricoarytaenoid muscle (PCA), respectively. In contrast, the antRLN is vulnerable if a ventilation tube is dislocated, with cuff-induced pressure to the glottic level. CONCLUSION: The increased knowledge in neurolaryngology provides the basis for a selective neuromonitoring to lower the risk of laryngeal paralyses after thyroid surgery.

Conservative approaches to the management of voice disorders.

The presence of a voice disorder not only affects social interaction but potentially also has a major impact on the work environment. The latter is becoming more important given the increasing demands employers make in terms of competency in both communication skills and adequacy of phonation. The development of newer and more precise phono-microsurgical techniques for the treatment of an increasing variety of voice disorders has not entirely replaced a conservative approach to voice rehabilitation. Nevertheless, conservative methods have to demonstrate an higher effectiveness in comparison with the microsurgical intervention given the alternative indications. This would be especially true for the more specific and systematically a given individual glottic pathophysiology could be changed in direction of individual phonatory physiology or supplementary phonation mechanism. This desired changing depends not only on the theoretical concepts but also on maintaining strict therapeutic principles during their clinical application. Conservative management of voice disorders has to be intensive and comprehensive, especially in the case of accepting our model of Larnygeal Double Phonation Function and the existence of a phonatory feedback loop.