Functional dysphonia: causes, symptoms, diagnosis, treatment

Functional dysphonia is a disorder of the voice function, characterized by incomplete closure of the vocal cords in the absence of pathological changes in the larynx; observed in neurotic conditions.

Synonyms

Phonasthenia, aphonia (functional aphonia), hypotonic dysphonia (hypokinetic, hypofunctional dysphonia), hypertonic dysphonia (hyperkinetic, hyperfunctional dysphonia), hypo-hypertonic dysphonia (vestibular-fold, false-fold voice).

ICD-10 code

Absent.

Epidemiology

The disease is diagnosed in 40% of patients with voice disorder. Persistent hypotonic dysphonias account for 80% of functional voice disorders.

Screening

Screening of voice disorders is carried out by assessing the voice by ear, its correspondence to the patient's gender and age. Changes in the pitch, timbre, strength and working range of the voice, rapid fatigue, impaired phonation breathing, intelligibility and fluency of speech indicate a disease of the vocal apparatus,

Classification

Depending on the type of voice production and the nature of the closure of the vocal folds, a distinction is made between: aphonia; hypo-, hyper- and hypo-hypertonic dysphonia. According to the etiopathogenetic factor, mutational, psychogenic and spastic dysphonia are distinguished.

Causes of functional dysphonia

The main etiological factors in the development of functional voice disorders are considered to be constitutional, anatomical, congenital features of the vocal apparatus, voice strain, psychotraumatic factors, previous respiratory diseases, asthenic syndrome of any etiology. Hypotonic disorders can also develop against the background of prolonged silence, as well as after surgical interventions on the larynx with atrophy of the vocal folds. Anxiety and depressive disorders are the cause of functional dysphonia in 29.4% and in spasmodic dysphonia in 7.1% of cases. Hormonal disorders are diagnosed in 52% of patients with functional dysphonia, most often thyroid disease. Other causes are neurological diseases such as Parkinson's disease and myasthenia, traumatic brain injury, cerebrovascular accident, etc.

Pathogenesis of functional dysphonia

Functional dysphonias are manifestations of disturbances in processes at different levels of conditioned reflex relationships. Over time, they acquire the character of a pathology of the predominantly peripheral part of the vocal apparatus - the larynx.

Functional changes are reversible, but in some cases they can lead to organic changes in the larynx. For example, long-term hypotonic dysphonia or psychogenic aphonia leads to the development of atrophic laryngitis with the formation of a vocal fold groove. At the same time, false-fold phonation is formed, which causes hypertrophy of the vestibular folds. Hyperkinetic dysphonia is the cause of persistent disturbances in the microcirculation of the vocal folds and the appearance of granulomas, ulcers, polyps, nodules and other pathologies of the larynx. In elderly patients, the development of functional disorders of the voice function is due to age-related changes in the larynx and the body as a whole; they are characterized by hypotonic dysphonia.

The mechanism of disease development during voice mutation is associated with discoordination of the transition from the falsetto mechanism of voice formation to the chest one. During the mutation period, the frequency of the fundamental tone changes, associated with the enlargement of the larynx. In boys, the pitch of the voice decreases by an octave, the vocal folds lengthen by 10 mm and thicken. In girls, the pitch of the voice decreases by 3-4 semitones, and the length of the vocal folds changes by 4 mm. Normally, the mutation is completed within 3-6 months. Hormonal disorders and psychoemotional factors can be the causes of pathological mutation.

The pathogenesis of spasmodic dysphonia has not yet been fully studied. The disease is classified as a focal form of muscular dystonia along with such nosology as spasmodic torticollis, writer's cramp, etc.

Symptoms of functional dysphonia

The clinical picture of functional dysphonia is caused by a violation of the vocal function of varying degrees of severity.

Hypotonic dysphonia is a disorder of the voice function caused by a decrease in the tone of the vocal folds and other muscles involved in voice formation. Rapid fatigue of the voice and aspirated hoarseness are noted.

Hypertonic dysphonia is a disorder of the voice function caused by an increase in the tone of the vocal folds. Phonation is performed with tension in the neck muscles, the voice is harsh, and hoarseness is pronounced.

Hypo-hypertonic dysphonia (vestibular-fold voice) is a disorder of the vocal function due to a decrease in the tone of the vocal folds with the formation of phonation at the level of the vestibular folds with the subsequent development of their hypertrophy.

Aphonia is the lack of sonority in the voice while maintaining a whispered speech.

Psychogenic dysphonia or aphonia is a disorder of the voice function, the leading etiological factor of which is considered to be psychogenic.

Mutational dysphonia is a voice disorder that occurs during the mutation period.

Spasmodic dysphonia is a voice disorder characterized by tense, compressed, intermittent phonation, trembling, hoarseness, and speech intelligibility problems. There are abductor and adductor forms. During speech, twitching of the diaphragm is noted. Articulation disorders and changes in the psychoemotional sphere are diagnosed. Clinical and neurological examination reveals organic pathology in the form of dystonic syndromes (such as writer's and blepharospasm, torticollis, etc.).

Diagnostics of functional dysphonia

Functional dysphonia is characterized by a long-term disorder of the voice function - several weeks, months and even years. Its instability is noted, the voice worsens after exertion, against the background of a deterioration in the general condition, after viral infections.

Physical examination

Of great importance for the diagnosis of voice disorders, especially of a functional nature, is a subjective assessment of the voice, which can be supplemented by stress tests (for example, reading aloud for 40 minutes), as well as psychological testing to identify somatoform disorders. When listening to speech, attention is paid to the tonality, strength, working dynamic range, timbre, features of the vocal attack, diction, the nature of phonation breathing, the work of the articulatory apparatus, the state of the neck muscles and the posture of the person being examined.

Instrumental research

For differential diagnostics of voice disorders, laryngo-microlaryngo-, microlaryngostrobo-, vibeolaryngostrobo-, endofibrolaryngolaryngolaryngoscopy, tracheoscopy, acoustic voice analysis, determination of the time of maximum phonation, spectral computer analysis of the voice, assessment of the function of external respiration, gloto- and electromyography, X-ray tomography of the larynx and trachea, CT of the larynx are performed.

In hypotonic dysphonia, microlaryngoscopic examination reveals incomplete closure of the glottis during phonation. Its shape may be different - in the form of an elongated oval, a linear slit or a triangle in the posterior third of the vocal folds. The atrophic form is characterized by thinning of the edge of the vocal fold in the form of a groove, atrophy of the vocal folds. Microlaryngostroboscopic examination allows us to identify the predominance of weakened phonatory vibrations of the vocal folds of small or medium amplitude, uniform in frequency. The displacement of the mucous membrane along the edge of the vocal fold is determined quite clearly. Acoustic examination reveals a decrease in the time of maximum phonation to an average of 11 s, a decrease in voice intensity in women to 67 dB, in men - to 73 dB. In the atrophic form, phonatory vibrations are absent or asynchronous in frequency and amplitude, all patients are characterized by incomplete closure of the glottis. Displacement of the mucous membrane along the free edge is not determined. In case of aphonia, the absence of closure of the vocal folds is noted during laryngoscopy.

The laryngoscopic picture of hypertonic dysphonia is characterized by an increase in the vascular pattern, the mucous membrane is often hyperemic, and phonation reveals closure of the vocal folds. Gradually, a false-fold voice is formed. Microlaryngostroboscopy is characterized by an extension of the closure phase, small-amplitude fluctuations with a slight displacement of the mucous membrane along the edge. Hypertonic dysphonia often leads to the development of granulomas, nodules, hemorrhages of the vocal folds, and chronic laryngitis. With a long course, a false-fold voice is formed. Hypertrophy of the vestibular folds develops. In some cases, the vocal folds are not visible, and phonation visualizes the closure of the vestibular ones.

In mutational dysphonia, the larynx picture may be normal; sometimes an increase in the vascular pattern of the vocal folds, an oval cleft during phonation, or a triangular cleft in the posterior parts of the larynx (“mutational triangle”) is detected.

In the abductor form of spasmodic dysphonia, the microlaryngoscopic picture is characterized by signs of hyperfunctional dysphonia: closure of the vocal folds, false-fold phonation and tremor of the vocal folds, and increased vascular pattern. In the adductor form, the vocal folds do not close during phonation, forming a gap along the entire length.

Differential diagnostics

Differential diagnostics are necessary in case of aphonia with bilateral laryngeal paralysis, when the patient retains a vocalized cough. It is possible to conduct a test with suffocation. If auditory control of the voice is lost, its complete restoration is possible.

Indications for consultation with other specialists

In the process of diagnosis and treatment of voice disorders, a multidisciplinary approach is required with the involvement of a neurologist, endocrinologist, psychiatrist and speech therapist in the rehabilitation process.

Treatment of functional dysphonia

The approach to the treatment of functional dysphonia should be comprehensive. It is necessary to influence the etiopathogenetic factors: treatment of general somatic diseases, somatomorphic disorders, sanitation of foci of chronic infection.

Treatment goals

Formation of correct skills of stable phonation, increasing the endurance of the vocal apparatus.

Indications for hospitalization

Hospitalization is indicated when surgical treatment is necessary.

Non-drug treatment

The most effective method of treating functional disorders of voice functions is phonopedics. Articulation and breathing exercises. Acupuncture, psychotherapy and physiotherapy, and massage of the collar zone are actively used. Of the physiotherapeutic methods for hypotonic dysphonia, it is recommended to use electrical stimulation of the laryngeal muscles with diadynamic currents, amplipulse, and electrophoresis of the larynx with neostigmine methyl sulfate. Mutational dysphonia does not require special therapy, with the exception of the treatment of concomitant diseases, rational psychotherapy and phonopedics.

Drug treatment

Drug therapy for hypotonic dysphonia includes stimulants (Eleutherococcus senticosus rhizomes and roots, B vitamins, neostigmine methylsulfate 10-15 mg orally 2 times a day for 2 weeks, and drugs that improve microcirculation of the vocal folds.

In case of hypotypertonic dysphonia and false-fold phonation, general and local anti-inflammatory therapy of hypertrophic laryngitis is carried out.

Treatment of spasmodic dysphonia is carried out jointly with neurologists. GABAergic drugs, laryngeal muscle blockades, neck muscle massage and phonophoresis are used.

Surgical treatment

In cases of severe persistent hypotonic dysphonia, implantation surgery or thyroplasty are indicated, the purpose of which is to enhance the adduction of the vocal folds. In case of false-fold phonation with hypertrophy of the vestibular folds, surgical treatment consists of removing the hypertrophied areas of the vestibular folds. In the postoperative period, in addition to anti-inflammatory therapy, phonopedia and stimulating treatment are carried out, aimed at increasing the tone of the true vocal folds.

Further management

In some cases, it is necessary to continue phonopedia for several months. When treating people in voice-speech professions, especially vocalists, long-term observation with correction of the voice load is required.

The patient should be reminded that a change in voice is a symptom of a vocal apparatus disease, requiring a visit to an otolaryngologist to diagnose a voice disorder; failure to follow the doctor's recommendations, including those on vocal hygiene, can lead to the development of organic pathology of the larynx.

In case of functional dysphonia, the period of disability varies from person to person and averages 14-21 days.

Forecast

Mostly favorable. Persistent violation of the voice function, the long-term nature of the course leads to deterioration of the patient's communication. Functional voice disorders in the absence of proper therapy reduce the working capacity of practically healthy people, create a threat to working capacity.

Prevention

Prevention of voice function disorders consists primarily of maintaining voice hygiene, developing correct phonation skills, and training the speech and singing voice, especially in people with voice and speech professions. Timely diagnosis and treatment of general somatic diseases that lead to the development of dysphonia are of great importance.

[ 1 ], [ 2 ], [ 3 ]