Identification of symptoms for spasmodic dysphonia and vocal tremor: a comparison of expert and nonexpert judges.

UNLABELLED: Spasmodic dysphonia is a rare voice disorder that is most successfully treated by injection of botulinum toxin (i.e., BOTOX) into the affected laryngeal muscles. BOTOX is currently available for use by professionals outside of metropolitan voice centers who may be unfamiliar with this rare disorder. Patients may seek assessment and treatment locally from clinicians who are unfamiliar with the speech symptoms for adductor-type (ADSD) or abductor-type (ABSD) spasmodic dysphonia. Although these disorders have been described in the literature, the symptoms have not been well defined and may appear similar to those of vocal tremor or muscle tension dysphonia (MTD). Thus, patients with spasmodic dysphonia might not be easily identified by local clinicians for treatment. The purpose of the current study was to determine whether voice clinicians with infrequent exposure to patients with spasmodic dysphonia could learn to identify speech symptoms for ADSD and ABSD comparable to voice clinicians with extensive experience with these disorders. The ratings of five nonexpert judges were compared to the ratings obtained from three expert judges. The results of this study demonstrated that nonexpert judges could be trained to identify the speech symptoms associated with ADSD, ABSD, and vocal tremor. While the nonexpert judges tended towards false positive judgements for the speech symptoms of interest, the overall speech symptom profiles for each type of voice disorder appeared comparable to those obtained from the expert judges. The symptom identificationscales used, therefore, have potential for use by clinicians unfamiliar with these disorders for correctly identifying persons with symptoms of ADSD and ABSD. EDUCATIONAL OBJECTIVES: Readers will be able to (1) define the predominant speech symptoms reflective of the voice disorder categories of ABSD, ADSD, and vocal tremor; and (2) describe the methods utilized in a new perceptual training protocol for teaching clinicians how to identify predominant speech symptoms associated with the voice disorder categories of ABSD, ADSD, and vocal tremor.

Quantitative analysis of the anatomy of the epineurium of the canine recurrent laryngeal nerve.

The purpose of this investigation was to determine the amount of epineurium surrounding the recurrent laryngeal nerve (RLN) compared with a limb nerve, that to flexor hallicus longus (NFHL). Nerve samples were obtained from 10 adult dogs and studied using scanning electron microscopy and light microscopy to measure the relative proportion of epineurium and the relative proportions of adipose and collagenous tissue comprising the epineurium in both nerves. Significantly greater relative epineurial cross-sectional areas and adipose content were found in the RLN than in the NFHL. Based on observations on noncranial peripheral nerves, the findings indicate that the RLN is better protected against deformational forces associated with compression than stretching forces. The RLN may not be structured well for successful reinnervation after injury. The patterns observed for adipose tissue in RLN epineurial tissue appeared unique compared with those previously reported in peripheral nerves. The primary role associated with adipose tissue is to 'package' the nerve for protection. The RLN is considered to be a vital nerve in the body, as are other cranial nerves. The large proportions of adipose tissue in the epineurium may relate to the importance of protecting this nerve from injury.

Modulation of laryngeal responses to superior laryngeal nerve stimulation by volitional swallowing in awake humans.

Laryngeal sensori-motor closure reflexes are important for the protection of the airway and prevent the entry of foreign substances into the trachea and lungs. The purpose of this study was to determine how such reflexes might be modulated during volitional swallowing in awake humans, when persons are at risk of entry of food or liquids into the airway. The frequency and the amplitude of laryngeal adductor responses evoked by electrical stimulation of the internal branch of the superior laryngeal nerve (ISLN) were studied during different phases of volitional swallowing. Subjects swallowed water on command while electrical stimuli were presented to the ISLN at various intervals from 500 ms to 5 s following the command. Laryngeal adductor responses to unilateral ISLN stimulation were recorded bilaterally in the thyroarytenoid muscles using hooked wire electrodes. Early ipsilateral R1 responses occurred at 17 ms, and later bilateral R2 began around 65 ms. The muscle responses to stimuli occurring during expiration without swallowing were quantified as control trials. Responses to stimulation presented before swallowing, during the swallow, within 3 s after swallowing, and between 3 and 5 s after a swallow were measured. The frequency and amplitude of three responses (ipsilateral R1 and bilateral R2) relative to the control responses were compared across the different phases relative to the occurrence of swallowing. Results demonstrated that a reduction occurred in both the frequency and amplitude of the later bilateral R2 laryngeal responses to electrical stimulation for up to 3 s after swallowing (P = 0.005). The amplitude and frequency of ipsilateral R1 laryngeal responses, however, did not show a significant main effect following the swallow (P = 0.28), although there was a significant time by measure interaction (P = 0.006) related to reduced R1 response amplitude up to 3 s after swallowing (P = 0.021). Therefore, the more rapid and shorter unilateral R1 responses continued to provide some, albeit reduced, laryngeal protective functions after swallowing, whereas the later bilateral R2 responses were suppressed both in occurrence and amplitude for up to 3 s after swallowing. The results suggest that R2 laryngeal adductor responses are suppressed following swallowing when residues may remain in the laryngeal vestibule putting persons at increased risk for the entry of foreign substances into the airway.

Supraglottic activity: evidence of vocal hyperfunction or laryngeal articulation?

False vocal fold (FVF) adduction and compression of the arytenoid cartilages to the petiole of the epiglottis in an anterior to posterior (A-P) direction have been thought to characterize voice disorders with abnormally increased muscle tension or effort, often termed hyperfunctional voice disorders. To further evaluate the association between hyperfunctional voice disorders and supraglottic activity, we compared the incidence of static and dynamic supraglottic activity in individuals with normal laryngeal mucosa, normal voice quality, and no voice complaints to two populations: subjects with vocal fold nodules and subjects with complaints of dysphonia without visible vocal fold lesions, glottal incompetence, or impairment of arytenoid cartilage motion ("hyperfunctional" group). Thirty-two subjects were assigned to one of these three groups (10 control, 12 nodule, and 10 hyperfunctional). Laryngeal movements were recorded using flexible videoendoscopy while a subject was performing speech tasks such as sustained phonation, syllable repetitions, sentence imitations, and conversation. Samples were randomized by subject and task and rated for presence or absence of A-P and FVF compression. Statistically significant group differences were found for FVF compression across speech tasks (chi-square, p<0.001). The control group had the smallest incidence (45%), nodule patients the next larger incidence (68%), and hyperfunctional patients the largest incidence (80%). Statistically significant group differences were found for A-P compression across speech tasks (chi-square, p<.05). The control group had the smallest incidence (74%), nodule patients the next larger incidence (78%), and hyperfunctional patients the largest incidence (92%). Statistically significant task differences were found for the presence of FVF compression in control subjects (chi-square, p<.005), hyperfunctional patients (chi-square, p<.025), and nodule patients (chi-square, p<.001), but not for A-P compression for any of the groups. A higher incidence of FVF compression was present for the speech tasks that included glottal stops. This context-specific variation in supraglottic activity suggested a dynamic component to FVF compression and also explained the high proportion of FVF compression in the control group. Each video sample was also rated for consistency of FVF or A-P compression to explore the static and dynamic nature of supraglottic activity. For samples on which raters agreed, A-P compression was typically present consistently, suggesting a static component, and FVF compression inconsistently, suggesting a dynamic component, for all three groups (chi-square, p<.001). These findings do not support previous suggestions that supraglottic activity may be a precursor to developing vocal fold nodules, as the nodule patients did not exhibit a higher incidence or consistency of A-P or FVF compression than patients with hyperfunctional voicing patterns in this study. Subjects in the hyperfunctional voice group were found to have static components of FVF and A-P compression. The presence of FVF compression in speech tasks that included glottal stops in the control group suggests an articulatory function at the laryngeal level.

Increased stability of airflow following botulinum toxin injection.

OBJECTIVES: The purpose of this study was to determine whether stability of airflow, as well as mean airflow, increased following botulinum toxin injection to laryngeal and extralaryngeal muscles in persons with spasmodic dysphonia (SD), some with associated vocal tremor (VT). STUDY DESIGN: Aerodynamic data were collected from five subjects before and at 2, 4, and 8 weeks after they received treatment by each of two different arms in an injection protocol in a crossover study. One arm of the protocol involved treatment of the thyroarytenoid muscles only. The other arm involved treatment of both the thyroarytenoid muscles and the strap muscles. METHODS: Measures of mean airflow and coefficient of variation (COV) of airflow during phonation were obtained. A decrease in the COV of airflow would indicate increased stability of phonatory airflow. RESULTS: Before treatment, all subjects with SD/VT exhibited mean airflows that were similar to controls. The COV of airflow ranged from normal to substantially elevated. Following botulinum injection, mean airflow characteristically increased and COV of airflow decreased. CONCLUSIONS: This finding suggests there is a change in the type, as well as the level, of activity in the muscles of speech production following botulinum toxin injection. The increase in airflow stability identified could be due to increased stability of the laryngeal system and possibly of the respiratory system as well.

Percutaneous radiologic, surgical endoscopic, and percutaneous endoscopic gastrostomy/gastrojejunostomy: comparative study and cost analysis.

PURPOSE: To compare the results and costs of three different means of achieving direct percutaneous gastroenteric access. METHODS: Three groups of patients received the following procedures: fluoroscopically guided percutaneous gastrostomy/gastrojejunostomy (FPG, n = 42); percutaneous endoscopic gastrostomy/gastrojejunostomy (PEG, n = 45); and surgical endoscopic gastrostomy/gastrojejunostomy (SEG, n = 34). Retrospective review of the medical records was performed to evaluate indications for the procedure, procedure technical success, and outcome. Estimated costs were compared for each of the three procedures, using a combination of charges and materials costs. RESULTS: Technical success was greater for FPG and SEG (100% each) than for PEG (84%, p = 0.008 vs FPG and p = 0.02 vs SEG). All patients (n = 7) who failed PEG subsequently underwent successful FPG. Success in placing a gastrojejunostomy was 91% for FPG, and estimated at 43% for PEG and 0 for SEG. Complications did not differ in frequency among groups. For gastrostomy, the average cost per successful tube was lowest in the PEG group ($1862, p = 0.02); FPG averaged $1985, and SEG $3694. SEG costs significantly more than FPG or PEG (p = 0.0001). For gastrojejunostomy, FPG averaged $2201, PEG $3158, and SEG $3045. CONCLUSION: Technical success for gastrostomy is higher for FPG and SEG than PEG. Though PEG is the least costly procedure, the difference is modest compared with FPG. For gastrojejunostomy, FPG offers the highest technical success rate and lowest cost. Due to high costs associated with the operating room, SEG should be reserved for those patients undergoing a concurrent surgical procedure.

Sources of error in estimation of laryngeal airway resistance in persons with spasmodic dysphonia.

Estimation of laryngeal airway resistance is a noninvasive method that has proven useful in the study of people with normal and some types of disordered voices. We were interested in examining more closely the application of this method to persons with spasmodic dysphonia (SD), a voice disorder sometimes associated with fluctuating airflow. We speculated unstable airflow could affect the estimation of subglottal pressure and laryngeal airway resistance. Oral pressure and airflow were collected from 10 subjects with SD and 10 control subjects during repetition of /pi/. The coefficient of variation (COV) of airflow during vowel production was calculated to quantify stability of airflow. The results indicated that although some SD subjects produced steady flows during the syllable repetition task, others exhibited substantially varying flows. Inability on the part of the subject to attain steady flows could compromise the usefulness of a midpoint measure of airflow and/or estimation of subglottal pressure, resulting in sources of error in estimation of laryngeal airway resistance. As a result, of the 10 subjects with SD in this study, laryngeal airway resistance could not be estimated in 6 subjects with unsteady flows. Laryngeal airway resistance was estimated in 4 SD subjects who produced steady airflow. Two of these subjects exhibited high laryngeal airway resistance; the others exhibited normal laryngeal airway resistance.

Comparison of aerodynamic and electroglottographic parameters in evaluating clinically relevant voicing patterns.

The purpose of the present study was to identify one or more aerodynamic or electroglottographic measures that distinguish among voicing patterns that are clinically relevant for nodule pathogenesis and regression: a presumably pathogenic pattern (pressed voice), a neutral pattern (normal voice), and two presumably therapeutic patterns (resonant voice and breathy voice). Trained subjects with normal voices produced several tokens of each voice type on sustained vowels /a/, /i/, and /u/. For each token, maximum flow declination rate, alternating current flow, and minimum flow were obtained from inverse-filtered airflow signals, and closed quotient and closing time were obtained from electroglottographic signals. The results indicate that for /a/ and /i/ (but not for /u/), the closed quotient provides a sensitive tool for distinguishing the voice types in physiologically interpretable directions. Further, post-hoc analyses confirmed a direct relationship between the closed quotient and videoscopic ratings of laryngeal adduction, which previous work links to nodule pathogenesis and regression.

The effects of a maxillary speech-aid prosthesis for the combined tongue and mandibular resection patient.

The purpose of this investigation was to develop a protocol for the fabrication of a prosthesis that would improve speech in individuals who have undergone complete removal of the tongue and mandible. A 60-year-old man was suffering from severe xerostomia and was unable to produce intelligible speech. Speech analysis without the prosthesis revealed a profound articulatory disorder. With the prosthesis, xerostomia was eliminated and the subject had fewer articulatory errors of severity. Improvement in speech intelligibility was significant at p less than 0.001.