Continuing Education Activity
Functional voice disorders are caused by insufficient or improper use of vocal mechanisms without any anatomic and neurological abnormalities. The most common causes of FVD include vocal fatigue, phonotrauma, muscle tension dysphonia, diplophonia, and ventricular phonation. This activity reviews functional voice disorders by discussing their etiology, epidemiology, and pathophysiology and the role of the interprofessional team in the evaluation, and treatment of patients with functional voice disorders.
- Identify the etiology of functional voice disorders.
- Outline the evaluation of functional voice disorders.
- Review the management options available for functional voice disorders.
Voice is an important medium for us to communicate and understand others. Any partial or total loss of voice makes mutual communication difficult. Problems with the voice can lead to severe functional and occupational impairment for singers, teachers, lawyers, and counselors besides all jobs that involve the communication of any nature. For e.g., In the case of leaders, actors, singers, newscasters, and media personnel, any changes to their voice may harm their voice qualities while lowering the impact of their speech. Thus, disorders of voice in these individuals have the potential to lead to great social and occupational impairment for the majority of individuals.
It is best to avoid such activities that can strain vocal folds like screaming, shouting, and talking above loud background noise as they may impact adversely. The human voice is produced with the help of the air supplied by the lungs accompanied by the vibration of vocal folds, so optimal glottic positioning controlled airflow from the lungs to the oropharynx contributes to the synchronized process of phonation. If there is any abnormality in the normal voice production process, it will eventually cause a voice abnormality. However, when vocal quality is compromised without any anatomical and neurological factors, a functional voice disorder should be suspected.
Organic voice disorders are caused by any alteration in respiratory, laryngeal, and vocal tract mechanism.
Voice disorders can be classified as follows:
- Structural organic voice disorders are a result of physical changes in the voice mechanism such as edema, vocal nodules, due to alteration in vocal fold tissues and age-related structural changes in the larynx.
- Neurogenic organic voice disorders (NOVD) are due to causes like vocal tremors, spasmodic dysphonia, or paralysis of vocal folds, etc. NOVD refers to the problems of the central or peripheral nervous system innervation to the larynx and vocal functioning mechanism.
- Functional voice disorders are caused by insufficient or improper use of vocal mechanisms without any physical structure abnormality or neurological dysfunction, and are frequently reported among teachers and have harmful consequences on their social and occupational functioning. Although there is a vast literature referring to the topic, yet there are differences in the concepts and methodology about voice disorders, as most studies do not present evidence for the vocal assessment and video laryngoscopic examination needed for a definite diagnosis. The most common FVDs are due to vocal fatigue, muscle tension dysphonia or aphonia, diplophonia, and ventricular phonation.
Studies have reported that the prolonged and frequent abnormal vocal function may develop pathological lesions of the larynx. Functional voice disorders result from vocal misuse or abuse. FVDs are more easily recognized than other psychosomatic disorders because the clinician can visualize the laryngeal structure and function. Multiple factors can affect voice functionality like voice quality, pitch, and loudness concerning the daily needs of an individual.
Functional voice disorders may include:
- Phonotrauma is caused by misuse, abuse, and overuse of voice (yelling, screaming, excessive throat-clearing, and talking with increased loudness with effort).
- Patients with underlying psychogenic conditions may develop psychogenic aphonia and dysphoria. These include anxiety, depression, and conversion disorder. These are often accompanied by blindness, paralysis, or other neurological symptoms.
Smoking is also reported as a cause of FVDs. According to a cross-sectional study performed in Korea, results revealed that in the Korean general population, smoking is associated with organic voice disorders independently. According to the study, poor vocal hygiene is another important factor that also affects voice function. Vocal hygiene as a preventive measure and vocal hygiene as a management technique for the individual having voice disorders have shown little but beneficial results.
Voice disorders have an estimated point prevalence of 20 million (0.98%) in the United States. Vocal abuse is the most common disorder among adults and children. Among adults, teachers are the most at-risk population. Several studies have proved a high number of incidences of voice disorders among teachers. A study was conducted in order to calculate the prevalence of voice disorders among teachers and know about the associated risk factors. A case-control study was conducted in 905 teachers. All the teachers were given a questionnaire to fill out, followed by a complete laryngeal exam (ear, nose, throat evaluation) and a videolaryngostroboscopy. The study concluded that 57% of the teachers were diagnosed with voice disorders, including vocal overstrain, which was most prevalent (18%). Another study reported a comparison of voice disorders between daycare center teachers and nursing staff. Results proved an increased level of voice disorders among teachers than the nursing staff.
The prevalence of voice disorders among teachers was 11.6% and 7.5% in the nonteacher population. Teachers also reported current and past voice disorder symptoms in high numbers as compared to nonteachers. Another study was done in the USA in a population of over 3 million teachers who were thought to be at higher risk of developing voice disorders than the general population. However, there is a considerable change in the estimated prevalence among teachers and the general population.
As per another study, 40% of dysphonia cases among functional voice disorders may be referred to as a multidisciplinary voice clinic where an ENT surgeon and speech-language pathologist (SLP) examine the laryngeal area related to vocal problems. A speech-language pathologist studies the patient’s vocal behavior patterns and works on a voice therapy treatment plan. Another study revealed that pediatric patients with voice or speech problems usually should receive a team assessment in which communication between the pediatricians or primary care physician, the otolaryngologist, and speech pathologist occurs.
According to various studies, there is no standardized nomenclature observed regarding any relationship between voice disorders and vocal fold pathology. Most of the voice pathologies are the result of aberrant vocal use. The poor vocal technique (speaking with a dry throat, harsh and rough way of speaking, etc.), poor oral care and hygiene, repeated laryngeal infection, and excessive throat clearing. Patients with chronic vocal problems may complain of a "lump in the throat" called Globus hystericus, dysphonia due to laryngeal muscle tension.
In recent years several advances regarding pathophysiology and diagnosis of voice disorders have developed with evidence of rapid and slow treatment efficacy.
History and Physical
This is very important to set the focused direction to achieve the targeted goal. When it comes to the question of patient care, professionals must be cautious and vigilant regarding the assessment of the patient’s complaint and problem that made them consult their provider. A detailed history of the patient’s voice concerns will help the clinician to diagnose a patient’s vocal problem and the cause behind it. Furthermore, it will help the clinician to understand the pathophysiology of the vocal complaints.
Assessment of functional voice disorders comprises taking the history of the patient’s vocal symptoms, medical history, the use of medications, occupation, any recent psychiatric or psychosocial stressors, emotional setback, laryngeal exposure to irritants like smoking, alcohol, occupational irritants, and misuse or abuse of voice.
A systematic and thorough evaluation of vocal mechanism and the patient’s voice problem is important from a therapy point of view, so an effective strategy for vocal function exercises can be planned accordingly. Functional dysphonia is a voice disorder having no organic lesion in the phonatory mechanism. Clinical evaluation for dysphonic patients is carried out in three steps.
- History Taking
- Physical Evaluation
The history-taking pertains to ascertaining medical, surgical, or accidental information essential to make a diagnosis and tailoring treatment to the patient.
The purpose of the vocal evaluation is to understand the anomaly (any change of voice affecting daily life needs like professional commitments, and unpleasantness for listeners due to roughness and hoarseness) of the voice production. The equality of voice, pitch, volume, and loudness will help the clinician to rule out the type of problem. Detailed vocal evaluation means a better understanding of the voice function leading to appropriate intervention.
Physical examination includes (during patient’s interview) a complete ear, nose, and throat examination after assessment of voice quality, loudness, and range of ease is done. The purpose of the assessment is to focus on nasal airway patency, pharyngeal function, and velopharyngeal competency to rule out the nature of the voice disorder. Some patients may need pulmonary analysis as they exhibit diminished breath support causing an alteration in the laryngeal mechanism, so the normal pattern of synchronized respiration and phonation is compromised. Evaluation of hearing ability is also important as hearing loss can influence the voice sound.
Laryngeal visualization or examination of the larynx for the internal structure is the most important step for the diagnosis of laryngeal disease. There are many ways of vocal fold and larynx examination, which include mirror laryngoscopy, flexible fiberoptic laryngoscopy, distal chip laryngoscopy, digital transoral laryngoscopy, and stroboscopy. Stroboscopy is considered to be the best method to evaluate a mass or any irregularity of vocal folds.
Due to the heterogeneity of functional voice disorders, an overview also includes psychogenic disorders and muscle tension voice disorders as subgroups based on observation. Clinical profiles of psychogenic voice disorders and muscle tension voice disorders are treated by speech-language pathologists who use symptomatic behavioral voice therapy along with models of counseling and psychotherapy.
Presentation of functional voice disorders can occur in many forms (dysphonia, stuttering, or prosodic abnormalities) and may mimic organic disorders, so diagnosis can be difficult. A thorough examination, correct diagnosis, and proper treatment can be very efficient. Functional or psychogenic disorders and behavioral movement disorders can be hard to identify due to their speech and voice disturbances. This is because many behavioral, neurological conditions can mimic symptoms of organic voice conditions. That is why clinicians find it challenging to make a diagnosis out of fear of being incorrect.
Treatment / Management
The first step in any treatment is the right diagnosis, so is the case with voice disorders. Multiple factors can be involved in the treatment depending on the cause, type, and severity of the disorder. Most problems can be managed by just knowing about the cause and by avoiding it.
There are mainly three treatments which include:
- Medical treatment
- Surgical treatment
- Voice therapy
Speech-language pathologists use a holistic approach striving for the balance for respiration, phonation, and resonance instead of directly addressing the symptoms of voice problems. Multiple rehabilitative strategies like auditory masking, Accent method, conversation training therapy (CTT), Lax Vox speech therapy, expiratory muscle strength training, phonation resistance training exercise, chant speech, and confidential voice are used treat and manage FVDs. Multiple facilitative techniques are used by SLPs to restore the patient’s normal voice depending on the type of voice disorder while also trying to know the underline reasons. Correct positioning, relaxation, hydration, vocal functioning exercises, counseling, patient education, and behavioral modification are part of the management.
In some cases, vocal fold nodules are successfully treated with voice therapy alone. In contrast, in other cases, there are certain types of lesions (laryngeal web, polyps, contact ulcers, and laryngeal papilloma) that need surgical management. In any case, the identification of the cause is the key to a successful treatment. Voice therapy is the standard-of-care for many of the nearly 140 million people in the United States who suffer from voice disorders. Yet, patients claim that current therapies are ineffective at meeting their voice needs.
The following is the differential diagnosis of FVDs:
- Somatoform disorder
- Conversion disorder
- Anxiety disorder
- Munchausen syndrome
- Allergic and environmental Asthma
- Bilateral vocal fold paralysis
- Exercise-induced asthma
- Foreign body obstruction
- Laryngeal abnormalities (eg, neoplasm, polyps, cyst)
Prognostic factors can be grouped into good and poor prognostic factors. Good prognostic factors include acute onset of symptoms, absence of underlying organic pathology, elimination of the identifiable stress, male gender, young age, and good general health status. Poor prognostic factors include personality disorder, poor perception of their own well being, motor symptoms, and psychogenic nonepileptic seizures.
For effective treatment and intervention, based on medical experience, it is essential to reach the closest possibilities relevant to the patient’s problems of concern. Direct speech therapeutic strategies might not benefit the patient who needs surgical treatment initially. A multidisciplinary approach (for the better diagnosis leading to good prognosis) for a patient who needs a voice prosthesis will help both otolaryngologist and a speech-language pathologist to make an interventional plan.
Patients may get upset and agitated when asked to repeat what they are saying, again and again. Vocal activity may be restricted as an avoidance strategy, resulting in social communication being compromised. Difficulty with communication may result in low self-esteem, anxiety, and depression. Poor compliance towards treatment can cause complications in long-term management resulting in poor patient outcomes. If a functional voice disorder is secondary to an underlying identifiable psychological stress, poor communication can result in the worsening of the associated psychiatric condition.
Deterrence and Patient Education
The mainstay of treatment of functional voice disorders is vocal rehabilitation, which is tailored according to patient presentation and prognosis. However, follow-ups and compliance have been an issue, as this is a long term treatment strategy. Patient outcomes can be improved by identifying multiple factors that affect patient compliance. A multifactorial diagnosis should be made initially to exclude neurological and psychiatric disorders. The elimination of organic causes and increased patient insight increases a patient's understanding of their condition and compliance. Assessment questionnaires can be provided to patients, so patient problems can be addressed and managed from a patient perspective.
Enhancing Healthcare Team Outcomes
The role of the multidisciplinary team in terms of delivering health care to the patient is essential to provide optimal outcomes in the treatment. It is important to have good interprofessional communication between the health care team. At the same time, it is pertinent to communicate clearly with the caregiver and the patient to improve health care outcomes.
Research has proved that working together reduces the number of medical errors and improves patient safety. An interprofessional team that provides a holistic and integrated approach regarding patient care can help in achieving the best possible outcomes of treatment. Patients with voice disorders may require a team consisting of an otolaryngologist, psychologist, psychiatrist, speech-language pathologist, and other health professionals. This multidisciplinary collaboration plays a vital role in achieving long-term patient-centered care to improve individual health outcomes and can enhance the chances of a patient’s quick recovery.