Psychogenic spasmodic dysphonia: a case study with expert opinions

Hyperactive sensorimotor cortex during voice perception in spasmodic dysphonia

Spasmodic dysphonia (SD) is characterized by an involuntary laryngeal muscle spasm during vocalization. Previous studies measured brain activation during voice production and suggested that SD arises from abnormal sensorimotor integration involving the sensorimotor cortex. However, it remains unclear whether this abnormal sensorimotor activation merely reflects neural activation produced by abnormal vocalization. To identify the specific neural correlates of SD, we used a sound discrimination task without overt vocalization to compare neural activation between 11 patients with SD and healthy participants. Participants underwent functional MRI during a two-alternative judgment task for auditory stimuli, which could be modal or falsetto voice. Since vocalization in falsetto is intact in SD, we predicted that neural activation during speech perception would differ between the two groups only for modal voice and not for falsetto voice. Group-by-stimulus interaction was observed in the left sensorimotor cortex and thalamus, suggesting that voice perception activates different neural systems between the two groups. Moreover, the sensorimotor signals positively correlated with disease severity of SD, and classified the two groups with 73% accuracy in linear discriminant analysis. Thus, the sensorimotor cortex and thalamus play a central role in SD pathophysiology and sensorimotor signals can be a new biomarker for SD diagnosis.

Development of a modified diagnostic classification system for voice disorders with inter-rater reliability study

Diversity in nomenclature and on-going dilemmas over the conceptual bases for the classification of voice disorders make it virtually impossible for the collation and accurate comparison of evidence-based data across different clinical settings. This has significant implications for treatment outcome studies. The first aim of this study was to develop a modified diagnostic classification system for voice disorders with clearly defined operational guidelines by which we might reliably distinguish voice disorders from one another. The second aim was to establish the face validity and reliability of the system as an effective diagnostic tool for the allocation of patients to different diagnostic groups for clinical and research purposes. After the Diagnostic Classification System for Voice Disorders (DCSVD) had been developed, it was used in an inter-rater reliability study for the independent assessment of 53 new consecutive patients referred to the Voice Analysis Clinics of three tertiary hospitals. There were three raters present for the assessment and diagnostic allocation of each patient. The high levels of inter-rater reliability suggest this may be a robust classification system that has good face validity and even at this early stage, strong construct validity.

Muscle tension dysphonia in Vietnamese female teachers

There has been no published research on muscle tension dysphonia (MTD) in speakers who use a tonal language. Using a sample of 47 Northern Vietnamese female primary school teachers with MTD, we aimed to discover whether professional voice users of tonal languages presented with the same symptoms of MTD as speakers of nontonal languages and whether they presented with additional symptoms as a result of speaking a tonal language. The vocal characteristics were assessed by use of a questionnaire and expert perceptual evaluation. Laryngeal features were assessed by photolaryngoscopy. The results showed that MTD was associated with a larger number of vocal symptoms than previously reported. However, the participants did not have the same vocal symptoms reported in English speakers, for example, hard glottal attack, pitch breaks, unusual speech rate, and glottal fry. Factor analysis of the vocal symptoms revealed three factors: "vocal fatigue/hyperfunction," "physical discomfort," and "voice quality," all of which demonstrated high reliability. The major laryngeal characteristic was a glottal gap. The glottal shapes observed included: 44.7% had an incomplete closure, 29.8% a posterior gap, 12.8% an hourglass-shaped gap, 8.5% a spindle-shaped gap, and 4.3% had complete glottal closure. The findings implied a potential contribution of linguistic-specific factors and teaching-related factors to the presentation of this voice disorder in this group of teachers.

The role of psychogenic and psychosocial factors in the development of functional voice disorders

The primary objective of this discussion paper is to review the available evidence for the role of psychogenic and psychosocial factors in the development of functional voice disorders (FVD). Current theoretical models linking these factors to the aetiology of FVD and to vocal hyperfunction are then considered. Since there is a paucity of solid empirical evidence to date, general patterns of evidence derived from single case reports and case series are examined first, followed by those empirical studies using more sophisticated methodologies. The discussion is structured around a framework that includes the following psychosocial areas of enquiry: demographic profiles of individuals with FVD; stressful incidents preceding onset; personality traits; coping styles and psychiatric disorder. Current evidence and associated theoretical models suggest that cognitive, affective, neurophysiological and behavioural aspects culminate in the development of these complex voice disorders. The implications of these findings are discussed with respect to clinical practice and clinical training, with suggestions for future scientific research.

Alterations in CNS activity induced by botulinum toxin treatment in spasmodic dysphonia: an H215O PET study

Speech-related changes in regional cerebral blood flow (rCBF) were measured using H(2)(15)O positron-emission tomography in 9 adults with adductor spasmodic dysphonia (ADSD) before and after botulinum toxin (BTX) injection and 10 age- and gender-matched volunteers without neurological disorders. Scans were acquired at rest and during production of continuous narrative speech and whispered speech. Speech was recorded during scan acquisition for offline quantification of voice breaks, pitch breaks, and percentage aperiodicity to assess correlations between treatment-related changes in rCBF and clinical improvement. Results demonstrated that speech-related responses in heteromodal sensory areas were significantly reduced in persons with ADSD, compared with volunteers, before the administration of BTX. Three to 4 weeks after BTX injection, speech-related responses were significantly augmented in these regions and in left hemisphere motor areas commonly associated with oral-laryngeal motor control. This pattern of responses was most strongly correlated with the objective measures of clinical improvement (decreases in the frequency of voice breaks, pitch breaks, and percentage aperiodicity). These data suggest a pathophysiological model for ADSD in which BTX treatment results in more efficient cortical processing of sensory information, making this information available to motor areas that use it to more effectively regulate laryngeal movements.

Type 2 thyroplasty for spasmodic dysphonia: fixation using a titanium bridge

OBJECTIVE

In order to facilitate surgery for spasmodic dysphonia, i.e. type 2 thyroplasty, a device was designed to fix the incised edges of the thyroid cartilage firmly.

MATERIAL AND METHODS

Various types and sizes of titanium bridge were developed for clinical use.

RESULTS

The results of surgery for spasmodic dysphonia were satisfactory in all 10 cases in which the new titanium bridge was used. No complications have been encountered to date.

CONCLUSION

Type 2 thyroplasty for spasmodic dysphonia was made easier to perform using the new titanium bridge, and more stable fixation of the reconstructed thyroid cartilage was achieved.

Psychogenic voice disorders--heroes or hysterics? A brief overview with questions and discussion

A brief overview of the field in relation to psychogenic voice disorders is given with reference to past and present terminology used, the common presentations seen, followed by the more subtle or ambiguous examples which may challenge our notions of psychogenic or clear-cut functional versus organic dichotomies. Issues related to aetiology, personality and psychological correlates are discussed, and a number of questions regarding the phenomenology of psychogenic dysphonia and its therapeutic resolution are raised. Since prevalence continues to be significantly in favour of women, it is suggested psychogenic voice disorder as a feminist issue might be worthy of our further consideration.

Thyroplasty for adductor spasmodic dysphonia: further experiences

OBJECTIVES

Two different surgical techniques for midline lateralization thyroplasty (type 2 thyroplasty) for adductor spasmodic dysphonia (SD) have been described, one using a composite graft and the other without. Indications and results for each method among different types of SD were compared, together with the theoretical background for the surgery.

STUDY DESIGN

Retrospective.

METHODS

The medical records of six patients with SD together with the fiberscopic video recording of laryngeal findings before, during, and after surgery were reviewed. The intraoperative video recordings of the surgical procedures were compared with the postoperative findings.

RESULTS

The vocal features of SD, diverse preoperatively, disappeared postoperatively and a normal, or almost normal, voice was attained in 5 of 6 cases. The failure in one patient was attributed to combined focal dystonia of the neck muscles and difficulty in lateralization. Type 2 thyroplasty without a graft, which causes bowing of both vocal folds, is simple to perform and effective enough for most SD cases. No recurrence has been noted so far over postoperative periods ranging from 6 months to more than 3 years.

CONCLUSION

The results suggest that thyroplasty is an effective therapeutic approach for SD.

Differentiation of spasmodic and psychogenic dysphonias with phonoscopic evaluation

OBJECTIVES

Identify laryngeal behaviors that differentiate patients with spasmodic dysphonia and patients with psychogenic dysphonia.

STUDY DESIGN

Retrospective review of patients evaluated over a 3-year period with a diagnosis of either spasmodic or psychogenic dysphonia. Videotaped phonoscopic (laryngeal imaging) examinations of all noted aberrant behaviors were examined. Tally behaviors according to each subject group.

METHODS

Three examiners unfamiliar with patients' previous diagnoses reviewed videotaped studies. Aberrant behaviors were noted and each patient was assigned to spasmodic or psychogenic dysphonia group. Agreement among examiners and agreement with previous diagnoses was established.

RESULTS

Six abnormal behaviors were noted, including tremor, hyperadduction, false fold constriction, sphincteric constriction, hyperabduction and paradoxical movements of the true and false folds. Percentage of patients in each group with each behavior was determined.

CONCLUSIONS

Individual behaviors did not generally appear to differentiate the two groups; however, patterns of behaviors did, and may be of considerable value in differentiating spasmodic and psychogenic dysphonias.

Phonatory air flow characteristics of adductor spasmodic dysphonia and muscle tension dysphonia

The purpose of this study was to determine if phonatory air flow characteristics differed among women with adductor spasmodic dysphonia (AdSD), muscle tension dysphonia (MTD), and normal phonation. Phonatory air flow signals were gathered during [pa] syllable repetitions. Mean phonatory air flow, coefficients of variation, and the presence of large air flow perturbations (75 ml/s or more) were examined for the three groups of speakers. There was no significant difference in mean phonatory air flow across groups, and very large intersubject variation in mean phonatory air flow occurred for both the AdSD and MTD groups. Coefficients of variation were similar for the groups of women with MTD and normal phonation but were significantly larger for the group with AdSD. Air flow perturbations were common with AdSD and rare with MTD. Relatively large coefficients of variation and air flow perturbations of at least 75 ml/s did occur for some women with normal voices who were 70 years of age or older. It appears that intrasubject variability in phonatory air flow may aid in the differentiation of AdSD and MTD when used in conjunction with other elements of a thorough voice evaluation. However, the potential contribution of aging to increased intrasubject variability in phonatory air flow must be considered when interpreting findings.

Treatment efficacy: voice disorders

This article reviews the literature on the efficacy of treatment for voice disorders primarily using studies published in peer-reviewed journals. Voice disorders are defined, their frequency of occurrence across the life span is reported, and their impact on the lives of individuals with voice disorders is documented. The goal of voice treatment is to maximize vocal effectiveness given the existing disorder and to reduce the handicapping effect of the voice problem. Voice treatment may be (a) the preferred treatment to resolve the voice disorder when medical (surgical or pharmacological) treatments are not indicated; (b) the initial treatment in cases where medical treatment appears indicated; it may obviate the need for medical treatment; (c) completed before and after surgical treatment to maximize long-term post-surgical voice; and (d) a preventative treatment to preserve vocal health. Experimental and clinical data are reviewed that support these roles applied to various disorder types: (a) vocal misuse, hyperfunction and muscular imbalance (frequently resulting in edema, vocal nodules, polyps or contact ulcers); (b) medical or physical conditions (e.g., laryngeal nerve trauma, Parkinson disease); and (c) psychogenic disorders (e.g., conversion reactions, personality disorders). Directions for future research are suggested which maximize clinical outcomes and scientific rigor to enhance knowledge on the efficacy of voice treatment.

Disfluency in spasmodic dysphonia: a multivariate analysis

This study examined visual analog scaling (VAS) judgments of disfluency by normal listeners in response to oral reading by speakers with spasmodic dysphonia (SD) and by nondysphonic controls, as well as the variables of frequency of occurrence of disfluencies, speaking rate, number of reading errors, and temporal acoustic measures of interword interval duration and articulation time. MANOVA yielded statistically significant differences between SD and control speakers for all variables except reading errors. Although no significant fluency-related differences were observed in terms of type of vocal spasm or voice tremor, significant differences in disfluency measures were obtained for clinical ratings of severity of dysphonia. Greater dysphonia severity ratings were associated with decreased fluency, but milder ratings were not necessarily associated with disfluency. Stepwise multiple regression analysis demonstrated that frequency of disfluency occurrence, speaking rate, and reading errors accounted for more than three fourths of the variability in VAS judgments of disfluency. Findings suggest that although disfluency is not a defining feature of SD, it does contribute significantly to the overall clinical impression of severity of the disorder.

Adductor spasmodic dysphonia: case reports with acoustic analysis following botulinum toxin injection and acupuncture

We analyzed frequency and duration parameters of voice and speech in two men with adductor spasmodic dysphonia (SD). One was treated with botulinum toxin injection; the other received acupuncture therapy. Improvement after acupuncture therapy in terms of standard deviation of fundamental frequency, acoustic perturbation measurements, durational measurements of voice and speech, and spectrographic analysis was comparable to the results achieved with botulinum toxin injection. Voice and speech parameters were stable 1 year after acupuncture therapy.

Muscle tension dysphonia and spasmodic dysphonia: the role of manual laryngeal tension reduction in diagnosis and management

Excessive activity of the extralaryngeal muscles affects laryngeal function and contributes to a spectrum of interrelated symptoms and syndromes including muscle tension dysphonia and spasmodic dysphonia. Recognition of the role of extralaryngeal tension is helpful in ensuring proper diagnosis and selection of appropriate treatment. This report demonstrates the application of manual laryngeal musculoskeletal tension reduction techniques in the diagnosis and management of laryngeal hyperfunction syndromes. The manual technique consists of focal palpation to determine 1) extent of laryngeal elevation, 2) focal tenderness, 3) voice effect of applying downward pressure over the superior border of the thyroid lamina, and 4) extent of sustained voice improvement following circum-laryngeal massage. The clinical utility of this innovative approach is discussed.