This article discusses and analyzes the diagnosis and management of voice disorders. Beginning with an insightful description of dysphonia as a sign and symptom rather than diagnosis, and an analysis of its unifying principles, the discussion continues with a review of evaluation, laryngoscopy, stroboscopy, and their respective advantages and disadvantages.
Key points
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Evaluation of voice disorders consists of the history, including a characterization of individual vocal demand and behavioral elements contributing to the voice disorder, perceptual assessment of the voice, and laryngoscopy.
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Dysphonia results from disruptions of phonatory physiology. To be most effective, diagnostic evaluation of dysphonia must focus on dynamic assessment of laryngeal function.
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Stroboscopy is the only technique that allows routine clinical imaging of vocal fold oscillation, and as a result is likely the single strongest diagnostic instrument in most cases of dysphonia.
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A discrepancy between the preliminary diagnostic impressions based in history and acoustic assessment and laryngoscopic findings is a warning that the evaluation is not complete. Rather than embarking in empiric treatment of poorly defined diagnoses, further, more refined imaging techniques must be used to resolve the discrepancy.
Videos accompany techniques discussed in this article: Flexible laryngoscopy showing vocal fold paresis , Stroboscopic examination demonstrating focal sulcus , Stroboscopic examination demonstrating phonotraumatic masses , Stroboscopy in the diagnosis of vocal cord nodules , Stroboscopy demonstrating absence of vibration in vocal fold can be viewed at http://www.oto.theclinics .
The diagnostic evaluation of voice disorders has always been an office-based undertaking. Its central task is visualization of the larynx, without which no definitive diagnosis may be made. Steady progress in laryngeal visualization has allowed ever more refined diagnoses to be made. However, quality differences in laryngoscopy have been largely ignored in the otolaryngology literature, which typically treats all types of office examination as if they were equal. In fact, examination quality has tremendous clinical impact in an area where functional disturbances can be caused by small or subtle abnormalities.
Although key, laryngeal visualization is also only a part of a broad and thoughtful approach to the complaint. A brief overview of the scope of such an evaluation before consideration of aspects of laryngoscopy is useful.
Evaluation of voice disorders
Hoarseness is the colloquial term for dysphonia; both terms are often used interchangeably in medicine to refer to altered voice quality. Hoarseness may be both a symptom and a sign of dysfunction of the phonatory apparatus. It is never a diagnosis, despite having a corresponding ICD code and sometimes serving as such for purposes of administrative convenience. The breadth of pathology that can cause hoarseness makes a unified overview a challenge; hoarseness is simply not a homogenous category after the first laryngoscopy. Nevertheless, certain unifying principles exist.
History
Voice disorders have resisted straightforward objective clinical characterization, despite the array of instrumental measures of acoustics and aerodynamics available. In most cases, important personal and subjective considerations influence the voice complaint, as well the patient’s treatment expectations. As a consequence, medical evaluation of voice disorders requires attention to several factors not encompassed by the usual history solicited from patients with head and neck complaints. These include careful characterization of the complaint, both with respect to its nature and its severity, and an assessment of the patient’s voice demands and habits. This approach emphasizes the functional limitations caused by the patient’s voice problems.
Through history taking, the otolaryngologist must first understand for what aspects of impaired voice production the patient seeks help. Patient perceptions of voice problems tend to be individual and directly connected with the amount and type of vocal demands; for example, a school teacher’s notion of “hoarseness” is likely to differ substantially from a singer’s or a construction foreman’s. The word “hoarseness” is used broadly to describe a variety of phenomena, and can refer to:
- •
Altered voice quality;
- •
Phonatory fatigue;
- •
Insufficient loudness;
- •
Restricted pitch range;
- •
Increased phonatory effort;
- •
Breathlessness;
- •
Impaired singing quality; and
- •
Other features.
It is not always the feature most obvious to the clinician which the patient finds troublesome.
The perception of the severity of these complaints is also subject to personal interpretation. Individuals have expectations and requirements of their voices that are not always a direct reflection of their occupational demands or other easily assessed factor, and often different from what the otolaryngologist might assume. Many people with dysphonia never seek medical attention, unaware that any problem exists. Others simply want to be reassured that their dysphonia is not caused by a malignancy. Still others complain of phonatory disturbances that are not apparent to the casual listener, and can even consider these crippling to professional or social activity. In part to help characterize the severity of an individual’s voice problem, several standardized and statistically validated questionnaires have been developed. Among them, the Voice Handicap Index and the Voice-Related Quality of Life are the most widely used. The Voice Handicap Index-10 is an abridgment of the former that makes it even easier to use without loss of statistical validity. Such inventories are useful to understand patient motivation and make appropriate treatment recommendations. Applied both before and after treatment, these can also form an important means of assessing outcome, which allows comparison among interventions, techniques, and studies.
Phonotrauma refers to the physical stress on the tissues of the vocal fold during phonation. It is considerable and has the potential to cause changes to the oscillatory properties of the vocal folds and local tissue injury. Because phonotrauma may be the single most important factor underlying most benign vocal fold lesions, assessing its extent and severity is an essential task of the voice history. Independent of medical factors, phonotrauma is related to amount and intensity of voice use, which in turn may be the product of vocal demand. Vocal demand usually results from an individual’s professional requirements, and inappropriate or excessive voicing, usually owing to an inherently talkative and extroverted personality. Distinguishing between demand and personal inclination is important to making appropriate treatment recommendations. The term “vocal abuse” has been used broadly and somewhat indiscriminately as a synonym for phonotrauma. However, it is not always correct, and almost never helpful, simply to blame the patient for his vocal predicament. Teachers, for example, are notoriously overrepresented among voice patients, owing largely to the relentless vocal demand of their work rather than any intrinsic behavioral factors.
Examination
The voice examination too has specialized elements, not least among them the use of the ear as a diagnostic instrument. Qualitative assessment of the voice precedes laryngoscopy. Gross abnormalities are readily apparent to the ear as the patient describes the complaint; more subtle ones require specific maneuvers and phonatory tasks to search for breakdowns of phonatory physiology. Low-intensity, high-pitched phonation which results in voice breaks, irregularities, and delays in voice onset suggests a small mucosal lesion. Reduced maximum phonation time (normally >20 seconds) and limitations in volume point to poor glottic closure. Phonation of a sustained vowel may be required to clearly reveal a tremor or other instability; connected speech or other complex task may be necessary to identify dysfluency such as laryngeal dystonia.
Based on the contents of the history and the voice assessment, the clinician should develop a diagnostic impression before visualization of the larynx. It is generally possible to assign a particular case to a category—mucosal disturbance, glottic insufficiency, or neurologic movement disorder—before laryngoscopy. Discrepancy between this preliminary impression and subsequent findings should serve as warning that the evaluation is not complete. A flexible fiberoptic examination that reveals no mucosal pathology when voice qualities suggest that it must be present is not a rare clinical situation. Rather than settling on a vague and nonspecific diagnosis—“chronic laryngitis” and “reflux” are the current favorites—the physician should progress to rigid endoscopy, stroboscopy, and even more specialized techniques to resolve the discrepancy.
The well-known GRBAS scale, and more recently, the CAPE-V, represent efforts to systematize qualitative voice assessment and standardize the terminology used. These serve a descriptive rather than a diagnostic purpose. Although not essential for routine clinical practice, they are useful to focus the assessment and for inquiry into clinical outcomes and efficacy.
Evaluation of voice disorders
Hoarseness is the colloquial term for dysphonia; both terms are often used interchangeably in medicine to refer to altered voice quality. Hoarseness may be both a symptom and a sign of dysfunction of the phonatory apparatus. It is never a diagnosis, despite having a corresponding ICD code and sometimes serving as such for purposes of administrative convenience. The breadth of pathology that can cause hoarseness makes a unified overview a challenge; hoarseness is simply not a homogenous category after the first laryngoscopy. Nevertheless, certain unifying principles exist.
History
Voice disorders have resisted straightforward objective clinical characterization, despite the array of instrumental measures of acoustics and aerodynamics available. In most cases, important personal and subjective considerations influence the voice complaint, as well the patient’s treatment expectations. As a consequence, medical evaluation of voice disorders requires attention to several factors not encompassed by the usual history solicited from patients with head and neck complaints. These include careful characterization of the complaint, both with respect to its nature and its severity, and an assessment of the patient’s voice demands and habits. This approach emphasizes the functional limitations caused by the patient’s voice problems.
Through history taking, the otolaryngologist must first understand for what aspects of impaired voice production the patient seeks help. Patient perceptions of voice problems tend to be individual and directly connected with the amount and type of vocal demands; for example, a school teacher’s notion of “hoarseness” is likely to differ substantially from a singer’s or a construction foreman’s. The word “hoarseness” is used broadly to describe a variety of phenomena, and can refer to:
- •
Altered voice quality;
- •
Phonatory fatigue;
- •
Insufficient loudness;
- •
Restricted pitch range;
- •
Increased phonatory effort;
- •
Breathlessness;
- •
Impaired singing quality; and
- •
Other features.
It is not always the feature most obvious to the clinician which the patient finds troublesome.
The perception of the severity of these complaints is also subject to personal interpretation. Individuals have expectations and requirements of their voices that are not always a direct reflection of their occupational demands or other easily assessed factor, and often different from what the otolaryngologist might assume. Many people with dysphonia never seek medical attention, unaware that any problem exists. Others simply want to be reassured that their dysphonia is not caused by a malignancy. Still others complain of phonatory disturbances that are not apparent to the casual listener, and can even consider these crippling to professional or social activity. In part to help characterize the severity of an individual’s voice problem, several standardized and statistically validated questionnaires have been developed. Among them, the Voice Handicap Index and the Voice-Related Quality of Life are the most widely used. The Voice Handicap Index-10 is an abridgment of the former that makes it even easier to use without loss of statistical validity. Such inventories are useful to understand patient motivation and make appropriate treatment recommendations. Applied both before and after treatment, these can also form an important means of assessing outcome, which allows comparison among interventions, techniques, and studies.
Phonotrauma refers to the physical stress on the tissues of the vocal fold during phonation. It is considerable and has the potential to cause changes to the oscillatory properties of the vocal folds and local tissue injury. Because phonotrauma may be the single most important factor underlying most benign vocal fold lesions, assessing its extent and severity is an essential task of the voice history. Independent of medical factors, phonotrauma is related to amount and intensity of voice use, which in turn may be the product of vocal demand. Vocal demand usually results from an individual’s professional requirements, and inappropriate or excessive voicing, usually owing to an inherently talkative and extroverted personality. Distinguishing between demand and personal inclination is important to making appropriate treatment recommendations. The term “vocal abuse” has been used broadly and somewhat indiscriminately as a synonym for phonotrauma. However, it is not always correct, and almost never helpful, simply to blame the patient for his vocal predicament. Teachers, for example, are notoriously overrepresented among voice patients, owing largely to the relentless vocal demand of their work rather than any intrinsic behavioral factors.
Examination
The voice examination too has specialized elements, not least among them the use of the ear as a diagnostic instrument. Qualitative assessment of the voice precedes laryngoscopy. Gross abnormalities are readily apparent to the ear as the patient describes the complaint; more subtle ones require specific maneuvers and phonatory tasks to search for breakdowns of phonatory physiology. Low-intensity, high-pitched phonation which results in voice breaks, irregularities, and delays in voice onset suggests a small mucosal lesion. Reduced maximum phonation time (normally >20 seconds) and limitations in volume point to poor glottic closure. Phonation of a sustained vowel may be required to clearly reveal a tremor or other instability; connected speech or other complex task may be necessary to identify dysfluency such as laryngeal dystonia.
Based on the contents of the history and the voice assessment, the clinician should develop a diagnostic impression before visualization of the larynx. It is generally possible to assign a particular case to a category—mucosal disturbance, glottic insufficiency, or neurologic movement disorder—before laryngoscopy. Discrepancy between this preliminary impression and subsequent findings should serve as warning that the evaluation is not complete. A flexible fiberoptic examination that reveals no mucosal pathology when voice qualities suggest that it must be present is not a rare clinical situation. Rather than settling on a vague and nonspecific diagnosis—“chronic laryngitis” and “reflux” are the current favorites—the physician should progress to rigid endoscopy, stroboscopy, and even more specialized techniques to resolve the discrepancy.
The well-known GRBAS scale, and more recently, the CAPE-V, represent efforts to systematize qualitative voice assessment and standardize the terminology used. These serve a descriptive rather than a diagnostic purpose. Although not essential for routine clinical practice, they are useful to focus the assessment and for inquiry into clinical outcomes and efficacy.
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