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Summary Botulinum toxin A injections in the left thyroarytenoid muscle were performed in 19 patients with adductor spasmodic dysphonia. Acoustic recordings were taken prior to and 1 week after injection and in a 2-week interval for a normal control group of 11 subjects. Fundamental frequency, standard deviation of fundamental frequency, jitter, shimmer, signal-to-noise ratio, and the voice break factor were studied. Each of the variables were measured from each subject's longest sustained phonation sample of the vowel quality /a/. Findings of the present study indicated: (a) Spasmodic dysphonia patients had significantly higher mean values of standard deviation of fundamental frequency, jitter, shimmer, and voice break factor and significantly lower mean values of signal-to-noise ratio when compared with normal controls; (b) a significant reduction post botulinum toxin injection was found for standard deviation of fundamental frequency and the voice break factor only

Objectives: Bilateral laryngeal paralysis results in airway obstruction, but the voice is often nearly normal. Tracheotomy provides an airway and preserves voice. Surgical procedures to statically enlarge the glottis can permit decannulation, but do so at the expense of the voice. Motion analysis in cadaver larynges has demonstrated that adductor and abductor muscles rotate the arytenoid cartilage around different axes. We sought to determine whether external rotation of the arytenoid cartilage could enlarge the airway without abolishing residual phonatory adduction. Methods: We performed arytenoid abduction in 6 patients with obstructing laryngeal paralysis. A suture was placed in the muscular process and posterior-inferior traction was applied, anchoring the suture to the inferior cornu of the thyroid cartilage. Outcomes were evaluated by assessing airway symptoms, by assessing the voice, and by documentation of laryngeal motion via videolaryngoscopy. Results: Three patients with severe stridor had marked relief of symptoms, and 2 of the 3 tracheotomy-dependent patients were decannulated. Three patients had good voices, 2 had mild breathiness, and 1 was very breathy. Conclusions: Arytenoid abduction is a promising treatment for relieving airway obstruction in patients with laryngeal paralysis. It has the potential to preserve voice in patients with residual phonatory adduction.

Objectives: The status of innervation in patients with laryngeal paralysis is somewhat controversial. Electromyographic activity has been frequently documented in the laryngeal muscles of patients with laryngeal paralysis, and animal experiments report a strong propensity for reinnervation after laryngeal nerve injury. However, a study of intraoperative electromyography performed in patients during reinnervation surgery failed to document activity with stimulation of the recurrent laryngeal nerve (RLN). Noting the long-observed differences in the symptoms of patients with vagus nerve injury and those with RLN injury, I hypothesized that reinnervation is influenced by the site of nerve injury. Methods: Cats were sacrificed at various intervals after resection of 1 cm of either the RLN or the vagus nerve, without any attempt to repair the nerve. Results: Four months after RLN resection, distal nerve biopsy revealed unmyelinated axons scattered through fibrous tissue. By 6 months, myelinated axons were organized, and electromyographic and histologic examination showed preferential reinnervation of the thyroarytenoid muscle. After vagotomy, the RLN was fibrotic and no axons were present. Both the thyroarytenoid and posterior cricoarytenoid muscles were fibrotic and had no electromyographic activity. Conclusions: The results confirm the strong propensity for laryngeal reinnervation after RLN injury, but not after vagus nerve injury. Preferential reinnervation of adductor muscles may account for a medial position of the paralyzed vocal fold.

Surgical adjustment of the arytenoid cartilage is a valuable tool in the surgical armamentarium for the treatment of laryngeal paralysis. While this approach is technically more difficult and requires more operative time than a type-I thyroplasty, it is much more effective in patients with a large glottic gap and posterior glottic incompetence.

Summary Botulinum toxin has been widely accepted as an effective therapy for controlling the symptoms of adductor spasmodic dysphonia (ADSD). Reported experience with botulinum treatment for abductor spasmodic dysphonia (ABSD) has been less impressive. Factors that may impair outcomes for ABSD include differences in the pathophysiology of ADSD and ABSD and limitation of maximal dose from airway restriction with posterior cricoarytenoid muscle (PCA) weakness. We report our experience with botulinum injection of the PCA with an asymmetric dose escalation protocol, based on clinical observations that in ABSD, abductor spasms are often stronger on one side, usually the left. The nondominant side was injected with 1.25 units. Dominant side dose began at 5 units, with step-wise increments of 5 units per week until one of three endpoints was reached: Elimination of breathy voice breaks, complete abductor paralysis of the dominant side, or airway compromise. Fourteen of 17 patients achieved good or fair voice, with dominant-side doses ranging from 10 to 25 units. Exercise intolerance limited PCA dose in two patients. One patient had persisting breathiness that improved with medialization thyroplasty. Asymmetric botulinum toxin injection into PCA muscles can suppress abductor spasm in patients with ABSD, but breathiness may persist, because of inadequate glottal closure.

The diagnosis and management of vocal fold paralysis remains a dominant clinical issue in laryngology. When a patient with vocal paralysis is identified without an obvious cause (such as recent cervical spine surgery), the otolaryngologist chooses from several additional investigations to help establish the nature and prognosis of the vocal fold paralysis. These investigations may be driven by the history and physical examination. Beyond this, the clinician may order blood tests, including serum glucose, rheumatoid factor, lyme titers, and ACE levels. What is the physiological basis for this? Is there any evidence to support this? These questions will be addressed in detail during the presentation. Radiographic studies remain a mainstay of investigation for the practicing otolaryngologist. “Imaging the course of the nerve” is a common approach cited in the evaluation of this important clinical entity. While this may be performed with chest radiography, computed tomography, or magnetic resonance imaging, it is difficult to draw many conclusions from the collective otolaryngology and radiology literature. The role of laryngeal electromyography in the management of vocal paralysis is an area of some controversy in the field. The literature on both sides of the controversy will be reviewed. Recommendations for clinical practice will be made. Short presentations on each of these topics will be followed by a critical analysis of the scientific basis of current practice. The relative strength and weakness of the evidence regarding these practices will be reviewed. A paradigm for the clinical evaluation of a suspected “idiopathic” vocal fold paralysis will be offered. Following this, illustrative cases will be presented in an interactive format. Audience questions are encouraged.

A single subject design was used to determine if pressure threshold training strengthens the inspiratory muscles in a subject with a limited glottal airway as well as diminish dyspnea and improve parameters of speech. The subject was a 19-year-old woman whose glottal airway was limited due to bilateral abductor vocal fold paralysis following a thyroidectomy. A 5-week inspiratory muscle strength-training program was implemented using a pressure-threshold trainer to strengthen the inspiratory muscles with the intent of enabling the generation of higher inspiratory pressures. The pressure threshold on the trainer was set at 75% of the subject's maximum inspiratory pressure (MIP). The subject was required to generate sufficient inspiratory pressure to bring air through the trainer during an inspiratory maneuver. MIP was the dependent variable used as an indication of inspiratory muscle strength. MIP increased by 47% following the training program. Maximal minute ventilation and oxygen uptake increased posttraining. Dyspnea during exercise and speech decreased as reported by the subject. Total reading duration and pause duration demonstrated a declining trend during connected speech. The results indicated that inspiratory muscle training using a pressure threshold device improves functional tasks such as exercise and speech in a subject with upper airway limitation.

Acoustic analysis of a reading passage was used to identify the abnormal phonatory events associated with adductor spasmodic dysphonia (ADSD) preand postinjection of Botulinum Toxin A (Botox). Thirty-one patients (age 22 to 74 years) diagnosed with ADSD were included for study. All patients were new recipients of Botox, and the examination of their voice occurred before and after their initial injection of Botox. Acoustic events were identified from reading samples of the Rainbow Passage produced by each of the patients. These events were examined from sentences containing primarily voiced sound segments. Dependent variables included the number of phonatory breaks, frequency shifts, and aperiodic segments—all variables previously defined by the investigators. Additionally, calculated variables were made of the percentage of time these events occurred relative to the duration of the cumulative voiced segments. A sexand age-matched control group (±2 years) was included for statistical comparison. Results indicated that those with ADSD produced more aberrant acoustic events than the controls. Aperiodicity was the predominant acoustic event produced during the reading, followed by frequency shifts and phonatory breaks. Within the ADSD group, the number of atypical acoustic events decreased following Botox injection. It is important that the occurrence of specific abnormal acoustic events was sufficient to differentiate the disordered speakers from the controls following as well as preceding initial Botox injection, as indicated by discriminant function analysis. This paper complements our previous work using this acoustic analysis method for defining the abnormal events present in the voice of those with ADSD and further suggests that these measures can be used in conjunction with perceptual impressions to differentiate speakers on the basis of initial severity.

• Congenital central alveolar hypoventilation (Ondine's curse) is a rare disorder with absence of automatic control of ventilation but preservation of voluntary breathing. Phrenic pacing, used to treat this condition, is usually not successful without a tracheotomy. We performed fiberoptic videoendoscopy on an affected infant airway. During wakefulness and ventilation by a negative pressure ventilator, the airway was normal, but with sleep onset, passive inspiration produced phasic epiglottic collapse. This case demonstrates the importance of central control in maintaining upper airway patency. ( Arch Otolaryngol Head Neck Surg. 1992;118:310-312)

Objective: To report outcomes of treatment for laryngeal contact granuloma. Study Design: Prospective treatment of 21 patients with laryngeal contact granulomas using proton-pump inhibitor (PPI) medication. Methods: Patients were diagnosed and followed by office endoscopy and patient interview. Results: Three patients did not tolerate PPI medication and were managed by treatment with type 2 histamine (H 2 ) blockers. The lesion completely resolved in 14 of the 18 patients maintained on PPI medication, and significantly regressed in the other 4. Residual granulomas were surgically excised in one patient. Lesions resolved in two patients following injection of botulinum toxin into one thyroarytenoid muscle. One patient had a residual lesion, but symptoms were controlled by medication, and he declined treatment with botulinum toxin. Of the three patients treated with H 2 -blocker medication, the lesion resolved in only one. Conclusion: PPI medication is effective in the treatment of laryngeal contact granuloma, even in the absence of identifiable symptoms of gastroesophageal reflux.

Objective: Describe a clinical syndrome of laryngeal hypersensitivity following laryngeal nerve injury. Study Design: Retrospective review of six patients with laryngeal paralysis sustained during neck surgery who presented with paroxysms of coughing and stridor, progressing to brief episodes of complete airway occlusion. Methods: Chart review. Results: Superior laryngeal nerve blockade temporarily improved symptoms in four of five patients. Botulinum toxin relieved spasm in two of three patients and reduced symptoms in the third. Symptoms gradually diminished or resolved in four patients from 1 to 2.5 years later. One patient underwent arytenoidectomy and one patient has a tracheostomy. Conclusions: Patients with laryngeal injury may present with stridor and acute airway obstruction secondary to paroxysmal laryngospasm. The authors have found that superior laryngeal nerve blockade or botulinum toxin may be effective in temporary relief of symptoms.

Summary It is frequently stated that unilateral cricothyroid muscle (CT) paralysis can be diagnosed by physical examination, noting rotation of the glottis, and shortening and vertical displacement of the ipsilateral vocal fold. These signs, however, are inconsistently observed, and there is considerable controversy regarding the direction of glottic rotation. To determine the effects of CT contraction on three-dimensional glottic configuration, we performed computerized tomography on cadaver larynges before and after simulated CT contraction. Radiopaque makers were used to compute distances. Unilateral CT contraction equally increased the length of both membranous vocal folds, and rotated the posterior glottis less than 1 mm. CT contraction neither adducted the vocal processes, nor significantly their altered vertical level. These results suggest that unilateral CT paralysis cannot be diagnosed on the basis of any clinically apparent change in glottal configuration.

We report the preliminary results of a phase I trial using indole-3-carbinol for the treatment of recurrent respiratory papillomatosis. Indole-3-carbinol is a chemical that is found in high concentrations in cruciferous vegetables and has been shown to alter the growth pattern of recurrent respiratory papillomatosis cell cultures and to be effective in an in vivo animal model of recurrent respiratory papillomatosis.Eighteen patients were treated with oral indole-3-carbinol and had a minimum follow-up of 8 months and a mean follow-up of 14.6 months. All patients received indole-3-carbinol, and outcome measures included a change in papilloma growth rate and the need for surgery during treatment compared with before treatment. All patients had serial examinations with videoendoscopy to document papilloma location and growth rate.Thirty-three percent (6 of 18) of the study patients had a cessation of their papilloma growth and have not required surgery since the start of the study. Six patients have had reduced papilloma growth rate, and 6 (33%) patients have shown no clinical response to indole-3-carbinol. Indole-3-carbinol affects the ratio of hydroxylation of estradiol; changes in the ratios of urinary 2-hydroxylation and 16-hydroxylation of estradiol caused by indole-3-carbinol correlated well with clinical response. No major complications or changes in the children's growth curve were noted.The preliminary results of treating recurrent respiratory papillomatosis with indole-3-carbinol holds promise. Longer follow-up of this patient group and a blinded, controlled trial are required. We conclude that indole-3-carbinol appears to be safe and well tolerated and may be an efficacious treatment for recurrent respiratory papillomatosis.

Summary Simultaneous measurements of mean airflow rate, vocal intensityand fundamental frequency were made during flexible video endoscopic recording of the vowel /i/ sustained in two vocal registers, modal and falsetto. The glottal closure patterns of four males and four females were evaluated by visually inspecting the video images. Acoustic signals were recorded and analyzed to verify the frequency and intensity criteria. Aerodynamic analysis of mean airflow rate was done via Rothenberg mask and commercial software. Incomplete glottic closure was common in both males and females. The degree of closure was significantly higher for modal samples than for falsetto samples with frequency and intensity held constant. The shape of the glottal closure did not vary with changes in the mode of phonation. As expected, the mean airflow rate increased with decreased glottal closure. The results suggest that incomplete glottic closure should be considered as a normal glottal configuration in high frequency modal and falsetto phonation. Moreover, hourglass and spindle glottal configurations may also be found in both the modal and falsetto registers of normal subjects. These results also confirm the positive relationships between degree of glottal gap and mean airflow rate. Thus, mean airflow rate may be regarded as a criterion for judging degree of glottal closure.

Videoendoscopy suggests that arytenoid adduction (AA) surgery not only medializes the paralyzed vocal fold, but increases the length of its membranous portion so that it more closely resembles the normal side. This could represent either real length change or out-of-plane rotation. Computed tomography scanning was performed on adult male cadaver larynges before and after the AA procedure to measure changes in length and spatial orientation of the vocal fold. Three-dimensional coordinates of radiopaque markers on the anterior commissure, posterior glottic midline, and vocal processes were determined. The distance between the vocal processes was 3.9 mm before, and 0.8 mm after AA. The mean vocal fold length was 12.4 mm before, and 13.4 mm after AA (p = .14). The vocal process moved consistently caudally, an average of 3.5 mm (p = .02). The data suggest that clinically apparent vocal fold length changes with AA could be an illusion due to vertical displacement of the vocal process, and not actual lengthening.

Since laryngeal botulinum toxin (BTX) injections have become the treatment of choice for spasmodic dysphonia, the purpose of this study was to examine its effects on the stability of the upper vocal tract as compared to the effects on glottic stability. Two different acoustic methods were used to analyze voice samples from 16 patients with adductor-type spasmodic dysphonias before and after BTX therapy and from a normal control group. Independent acoustic analyses were used to determine laryngeal and upper vocal tract stability. The results showed significantly higher values for the standard deviation of fundamental frequency (SDFO), reflecting laryngeal instability, for the patient group than for the control group and an impressive improvement for the patients after BTX therapy. Further, the equally high values of SDFO for the initial second and a second from the midsegment of phonation were differentially reduced by BTX therapy, resulting in a normal pattern of laryngeal stability during sustained phonation. The variability of the first and second formants, reflecting upper vocal tract instability, showed higher values for the patients compared with the control group, but this difference was not statistically significant. The present findings showed that BTX injections to the thyroarytenoid muscle had no discernible effect on stability of the upper vocal tract.

A 53-year-old man with severe vocal fold atrophy underwent bilateral type 1 thyroplasty and anterior commissure advancement. Postoperatively, he developed a strained voice with less projection and volume than prior to surgery. This was verified by objective assessment of vocal function. Videoendoscopy revealed bilateral false vocal fold fullness and blunting of the anterior commissure. Magnetic resonance imaging demonstrated cephalic migration of the posterior ends of the implants and retrusion of the anterior commissure segment. Surgical exploration revealed that the type 1 implants had rotated and buckled. The anterior commissure segment was rotated and displaced inferiorly, and its inferior surface was tethered to the cricoid by scar tissue. The implants were removed, the anterior segment was repositioned and rigidly fixed, and bilateral lipoinjection performed. Vocal function was significantly improved, and endoscopy revealed normal tension and length of the vocal folds and restoration of the anterior commissure. This case demonstrates the importance of stable fixation during laryngeal framework surgery.

Bilateral laryngeal paralysis can result in severe airway compromise. A widely accepted treatment is endoscopic laser total arytenoidectomy (TA); however, vocal results are usually poor. An alternative approach, resection of only the medial portion of the arytenoid (medial arytenoidectomy [MA]), has the potential for less vocal impairment, but may not provide a sufficient airway. Laryngeal resistance (LR) was measured in vivo and ex vivo in 12 adult mongrel dogs with bilateral laryngeal paralysis after TA, MA, or no surgery (controls). The LR was significantly lower than in controls in both TA and MA, but there was no significant difference between TA and MA. Glottic area was also significantly higher in both MA and TA compared to controls, but again, there was no significant difference between TA and MA. Phonation could be elicited in all controls and 2 of 4 dogs with MA, but no dogs with TA. Our results show that MA offers airway improvement similar to that with TA and also has the potential for better vocal function.

Objective: To identify objective parameters that could serve as valid indicators of vocal function in evaluating patients treated at multiple centers for head and neck cancer. Design: Objective measures of voice were validated against functional outcome measures of voice and communication. Setting: A multidisciplinary university-based ambulatory head and neck cancer clinic. Subjects: Fifteen patients at varying posttreatment intervals after chemoradiation therapy for head and neck cancer and 5 volunteers with no cancer but with a history of heavy smoking and drinking. Main Outcome Measures: Acoustic and aerodynamic parameters were measured in patients with head and neck cancer after treatment with combined chemotherapy and irradiation and in control subjects. Communicative function was assessed by perceptual assessment of recorded voice samples, by a clinician-based communication score, and by patient self-rating of voice and communication. Results: Both perceptual analyis and communication score were concordant with patient self-rating of voice and communication ability. Acoustic measures were abnormal in patients, and jitter scores correlated with listener ratings of perceived voice quality. However, acoustic measures did not relate to communication function, as assessed by either the patient or the clinician. Laryngeal resistance demonstrated a significant correlation with both patient and observer assessments of voice quality and communication function. Laryngeal resistance was on average twice as high in patients who complained of voice fatigue, but this difference was not statistically significant. Conclusions: Laryngeal resistance, determined during standardized phonation, is a reliable objective parameter of vocal function after chemoradiation therapy for head and neck cancer. A standardized clinician-based communication scale holds promise as a useful tool. Acoustic measures reflect the sound of the voice but not the ability to communicate effectively. Arch Otolaryngol Head Neck Surg. 1996;122:858-864

Congenital dacryocystoceles presenting with intranasal extension may precipitate respiratory distress in neonates. Twenty-one children have been described as having congenital dacryocystoceles with intranasal extension, and, of these, 14 had respiratory distress. We present a series of patients with congenital dacryocystoceles who presented with ranging degrees of respiratory distress. Magnetic resonance imaging and computed tomographic scans confirmed the diagnosis. In all cases, the endonasal portion of the cyst was marsupialized endoscopically with complete resolution of symptoms. Pertinent embryology, anatomy, clinical presentation, and treatment are discussed.

A combined-modality treatment program consisting of botulinum toxin injection (Botox) and voice therapy was used to treat 17 subjects diagnosed with adductor spasmodic dysphonia (ADD SD). Ten subjects with ADD SD served as the control and were given Botox only. Voice therapy after Botox injection was directed toward reducing the hyperfunctional vocal behaviors, primarily glottal overpressure at voice onset and anterior-posterior squeezing. The results indicated that subjects who underwent combined-modality treatment maintained significantly higher mean airflow rates for significantly longer periods. Moreover, there was a carryover effect in these patients when they received Botox only. Adductor spasmodic dysphonia is treated most effectively when intrinsic laryngeal muscle spasms are reduced or eliminated by Botox injection and extrinsic hyperfunctional vocal behaviors are treated with voice therapy.

Educational objectives: To identify patients with adductor and abductor spasmodic dysphonia and to understand and organize a comprehensive management program, including diagnosis and current treatment of patients with spasmodic dysphonia.

It has been recently noted that laryngeal paralysis results in a complex alteration of the glottis. The membranous segment of the paralyzed vocal fold is shortened, and, during phonation, patients use hyperfunction to shorten the normal vocal fold to about the same length. Additionally, if the paralyzed vocal fold is not near the midline, the angle between the membranous and cartilaginous segments of the vocal fold is decreased, resulting in a "posterior" gap which cannot be closed by hyperadduction of the normal side. To determine whether arytenoid adduction addresses these problems, videolaryngoscopy was analyzed in 11 patients before and after surgery, and results were compared to patient satisfaction and acoustic and aerodynamic assessment. The posterior gap and glottic competence were improved in all patients, but only 6 had improvement in symptoms. Two had persistent vocal fold bowing but achieved good function after Teflon injection. Three patients, all with paralysis for more than 20 years, had no increase in vocal fold length and very little subjective vocal improvement. Arytenoid adduction is most effective in acute cases. Poor functional results in chronic paralysis are related to failure to achieve vocal fold lengthening, presumably due to soft-tissue contracture.

To determine whether variation in suture placement could improve the results of the arytenoid adduction procedure, a model was developed using fresh human cadaver larynges. Three-dimensional (3-D) motion of the arytenoid was determined by utilizing computed tomographic imaging with radiopaque markers on the apex and muscular and vocal processes. By utilizing principles previously applied to the study of rigid body mechanics for the carpal, knee, and tarsal joints, rotation and translation of the arytenoid about the axial, coronal, and sagittal axes were calculated. Subglottic airflow resistance was measured before and after the procedure. Posterior glottic closure was reproducibly achieved, as determined by computed tomographic imaging and airway resistance. Conflicting reports on cricoarytenoid joint mechanics can be attributed to reliance on trigonometric analysis of two-dimensional images, which results in errors in out-of-plane motion. This paper presents a useful model for obtaining detailed anatomic information describing arytenoid 3-D motion.

The objectives of this study were to determine the effects of botulinum toxin injection on measures of depression, anxiety, and somatic complaints in patients diagnosed as having spasmodic dysphonia. Patients were asked to complete preinjection questionnaires with self-ratings of depression, state and trait anxiety, and somatic complaints. Approximately 1 week and 2 months following injection, patients were again asked to complete the questionnaires. The spasmodic dysphonic subjects exhibited significantly elevated mean levels of depression and anxiety. These levels were significantly reduced approximately 1 week after injection. Two months later, depression and anxiety measures did not change significantly from their 1-week postinjection values. The results suggest that patients with spasmodic dysphonia who demonstrate significantly elevated measures of depression and anxiety show a reduction in those measures following treatment with botulinum toxin.

It is widely accepted in the American literature that the cricothyroid muscle is responsible for the paramedian position of the vocal fold in recurrent laryngeal nerve paralysis. However, support in the literature for this theory is not conclusive, and the cadaveric vocal fold position expected after lesions of the vagus nerve has also been reported in patients with an intact superior laryngeal nerve. This study compares the configuration of the glottis in patients with unilateral paralysis due to known lesions of either the recurrent laryngeal or vagus nerve. Normal subjects were studied as controls. Results indicate that the alteration of glottic configuration in laryngeal paralysis cannot be adequately characterized by standard terms of vocal fold position. The paralyzed vocal fold is shortened, with anterior rotation of the arytenoid. Patients with vagus nerve lesions had a statistically insignificant tendency for a more lateral vocal fold position, but a discrete difference in position between the two groups was not identified. This study also confirms prior observations that paralyzed vocal folds are frequently not denervated. These findings have significant implications for management of laryngeal paralysis.

To assess the efficacy of bilateral or unilateral botulinum treatments for spasmodic dysphonia we injected botulinum toxin (type A) into the thyroarytenoid muscle of 24 patients with adductor type spasmodic dysphonia. Eleven patients underwent unilateral procedures and 13 bilateral procedures. Samples of sustained phonation were analyzed acoustically by a computer-assisted method and the air flow rates determined. All tests were conducted 1 week before injection and 1 week and 1 month after treatment. With unilateral injection, improvements in acoustic parameters occurred as early as 1 week after treatment. With bilateral injections, only the voice break factor was significantly reduced after 1 week, while standard deviations of fundamental frequency, jitter, shimmer and signal-to-noise-ratios were reduced 1 month after treatment. In comparison with unilateral injections, the mean air flow rate was twice as high 1 week after bilateral injections, with no significant differences found 1 month after treatment. Clinically, both injection modes resulted in the reduction of laryngeal spasms as early as within 48 h after injection.

Summary Perceptual ratings were obtained from voice samples of 19 patients with adductor spasmodic dysphonia before and 1 week after unilateral treatment with Botulinum toxin. Five experienced listeners judged samples of sustained phonation using a seven-point equal-interval scale. The perceptual parameters assessed were overall severity, strain-strangled voice quality, and breathiness. Perceptual results were related to the standard deviation of fundamental frequency and the voice break factor, two acoustic parameters previously shown to be significantly improved following Botulinum toxin injection. Results indicate that in general the spasmodic dysphonia voice is perceived as less severe, less strain-strangled, and more breathy 1 week after treatment. Interrelations among perceptual parameters and relationships with acoustic analyses are discussed.

Spasmodic Dysphonia is a disabling speech disorder characterized by excessive contractions of laryngeal muscles. Botulinum toxin has been demonstrated in several clinical trials to be very effective in improving speech in most patients and its clinical use is becoming more widespread. Although the benefits of botulinum toxin treatment are considerable, few patients achieve a totally normal voice and minor side effects are common. Clinical research is needed to determine the factors limiting improvement, to determine the role of adjunctive speech therapy, and to develop treatment protocols which will maximize benefits and diminish side effects.

In einer retrospektiven Studie wurden 50 Patienten mit beidseitigen Stimmbandparesen nach Schilddrusenoperationen analysiert, die zwischen 1988 und 1991 in der Universitats-HNO-Klinik untersucht und behandelt wurden. Bei allen Patienten fuhrten wir eine elektromyographische Untersuchung der gelahmten Stimmlippen (bevorzugt endolaryngeal aus den Mm. vocales) durch, um die Prognose der Stimmbandparesen einzuschatzen und das weitere therapeutische Vorgehen zu unterstutzen. Lies sich zumindest einseitig eine kraftige Willkuraktivitat eventuell auch mit sparlicher pathologischer Spontanaktivitat nachweisen, schatzen wir die Prognose als gunstig ein. Zeigte sich demgegenuber keine Willkuraktivitat oder nur einseitig geringe Willkuraktivitat und reichlich pathologische Spontanaktivitat, stuften wir die Prognose als ungunstig ein. Da drei Patientinnen interkurrent verstorben sind und an funf Patienten fruhzeitig eine einseitige Laterofixation durchgefuhrt wurde, konnen wir die EMG-Befunde von 42 Patienten dem klinischen Verlauf gegenuberstellen.

Prolonged apnea and cardiovascular changes have been elicited in infant animals by the application of water to the laryngeal mucosa. Previous reports have produced conflicting evidence in regard to the possible role of arterial chemoreceptors in modulating this reflex. The present study was designed to determine the effect of carotid body stimulation or suppression on the duration of apnea and severity of cardiovascular changes in response to water in the larynx of piglets. The role of swallowing in terminating the apnea was also investigated. Hypoxia and isoproterenol, both carotid body stimuli, caused decreased apnea duration. Hyperoxia was associated with prolonged apnea duration; however, dopamine, which inhibits carotid body chemoreceptors, produced no significant change. Hypotension and bradycardia were only observed after prolonged apnea or chemoreceptor stimulation, supporting the concept that the cardiovascular component of the laryngeal chemoreflex is a result of changes in blood gas concentration rather than a direct response to laryngeal chemostimulation. The interval between water application and initiation of swallowing was not significantly affected by hypoxia or carotid body stimulation and swallowing did not always occur before resumption of breathing.

Botulinum toxin has been previously reported to be successful in the treatment of spasmodic dysphonia. To objectively document results, 11 patients with adductor spasmodic dysphonia who received unilateral treatment of the thyroarytenoid muscle were studied. Acoustic analyses and airflow rates during sustained phonation and flexible videoendoscopy were performed prior to, 1 week and 1 month after injection. 1. Acoustic parameters demonstrated significant voice improvement, although abnormal characteristics remained. 2. Mean airflow rates were increased 1 week after injection with almost normal values 1 month later. 3. Videolaryngoscopy showed an effective reduction of intrinsic laryngeal muscle hyperfunction with less effect on extrinsic muscle activity. Interrelations between videolaryngoscopic rating scores, acoustic results and aerodynamic results are discussed.

We studied the effects of hypercapnia (Fl CO 2 = 0.07) and hypoxia (Fl O 2 = 0.13) on the cricothyroid muscle response (peak integrated CT EMG) to graded inspiratory resistance (R i ). Five anesthetized dogs spontaneously breathed through the upper airway (UAB) or a side arm of a tracheotomy cannula bypassing the larynx (TB). With room air UAB, graded increases in R i increased CT EMG, upper airway pressure change (Paw) and esophageal pressure change (Pes, indicating increased inspiratory drive), but decreased V t . For room air TB, the effects of R i were much less but still significant. Hypercapnia increased V t , f r , Pes, Paw and CT EMG for any given R i during UAB more than during TB. Hypoxia increased f r but did not increase V t , Pes, Paw, or CT EMG. The results are consistent with a model predicting CT activity as additive functions of inspiratory drive and laryngeal receptor stimulation by Paw and no direct effects of chemoreceptor stimulation on the CT, independent of those resulting from changes in inspiratory drive and upper airway pressure.

Previous studies investigated the use of acoustic perturbation measures as a screening tool for neuropathologies with conflicting results. In the present study, five parameters of phonatory function (jitter, shimmer, signal-to-noise ratio, fundamental frequency, and standard deviation of fundamental frequency) were obtained from samples of sustained phonation in three neuropathological groups (Parkinson, Huntington, cerebellar ataxia) and a normal control group to assess the use of acoustic measures in differential diagnosis. In addition, perceptual judgements of the severity of dysphonia for each patient were obtained. The results indicated that perturbation measures of the neuropathological groups showed a higher degree of variability compared to normals. From the five parameters studied, only the standard deviation of fundamental frequency differentiated among neuropathological subgroups. The acoustic parameters studied did not clearly reflect the perceived dysphonia for all subgroups.

The cricothyroid muscle serves as an accessory muscle of respiration in anesthetized animals. The functional significance of this activity is unknown. To determine respiratory cricothyroid muscle activity in conscious humans, cricothyroid muscle electromyogram was measured percutaneously, along with posterior cricoarytenoid muscle electromyogram and esophageal pressure in six volunteers. Low level cricothyroid muscle activity with quiet breathing was observed in four subjects. In all subjects, cricothyroid muscle activity was recruited by voluntary deep breathing, brief airway occlusion, and hypercapnia. Continuous positive airway pressure at 7.5-cm H2O increased expiratory cricothyroid muscle activity in all subjects, and suppressed inspiratory activity in five. These results indicate that respiratory reflexes of the cricothyroid muscle are operative in conscious humans.

To evaluate expert listeners' perceptions of voice and fluency in persons with adductor spasmodic dysphonia (ADSD) before and after treatment with botulinum toxin type A (Botox), as a function of initial severity of the disorder (while controlling for patients' age at injection).Simple before-and-after trial with blinded randomized listener judgments.Ambulatory care clinic at a single medical center.Forty-two consecutive patients with ADSD who underwent examination, with a 3- to 6-week follow-up, after initial botulinum toxin type A injection. There were also 42 age- and sex-matched healthy control subjects.Injections of botulinum toxin type A into the thyroarytenoid muscle(s).Computer-implemented visual analog scaling judgments of voice quality and speech fluency made by expert listeners under psychoacoustically controlled conditions.Response to botulinum toxin type A varied markedly as a function of pretreatment severity of ADSD. More severe initial symptoms exhibited greater magnitudes of improvement. Patients with mild dysphonia did not exhibit pretreatment to posttreatment change. Following treatment, voice and fluency remained significantly (P.05) poorer in ADSD than in healthy speakers. Older patients exhibited less improvement than younger patients when the effect of initial severity was statistically controlled.Voice quality and fluency improved for most patients following treatment, but older patients and those with milder dysphonia exhibited the least optimal responses to the procedure. Patients who were profoundly impaired demonstrated the greatest amount of improvement. Computer-implemented visual analog scaling provided a reliable clinical tool for determining treatment-related changes in those with ADSD.

This study investigated relationships between acoustical indices of spasmodic dysphonia and perceptual scaling judgments of voice attributes made by expert listeners. Audio‐recordings of The Rainbow Passage were obtained from thirty one speakers with spasmodic dysphonia before and after a BOTOX injection of the vocal folds. Six temporal acoustic measures were obtained across 15 words excerpted from each reading sample, including both frequency of occurrence and percent time for (1) aperiodic phonation, (2) phonation breaks, and (3) fundamental frequency shifts. Visual analog scaling judgments were also obtained from six voice experts using an interactive computer interface to quantify four voice attributes (i.e., overall quality, roughness, brokenness, breathiness) in a carefully psychoacoustically controlled environment, using the same reading passages as stimuli. Number and percent aperiodicity and phonation breaks correlated significanly with perceived overall voice quality, roughness, and brokenness before and after the BOTOX injection. Breathiness was correlated with aperidocity only prior to injection, while roughness also correlated with frequency shifts following injection. Factor analysis reduced perceived attributes to two principal components: glottal squeezing and breathiness. The acoustic measures demonstrated a strong regression relationship with perceived glottal squeezing, but no regression relationship with breathiness was observed. Implications for an analysis of pathologic voices will be discussed.