Vocal cord nodules are bilaterally symmetrical
benign
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
white masses that form at the midpoint of the
vocal folds
In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speec ...
.
Although diagnosis involves a
physical examination
In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the pati ...
of the
head and
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
, as well as perceptual voice measures, visualization of the vocal nodules via laryngeal
endoscopy
An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...
remains the primary diagnostic method.
Vocal fold nodules interfere with the vibratory characteristics of the vocal folds by increasing the
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...
of the vocal folds and changing the configuration of the vocal fold closure pattern.
Due to these changes, the quality of the voice may be affected. As such, the major perceptual signs of vocal fold nodules include vocal hoarseness
A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...
and breathiness. Other common symptoms include vocal fatigue, soreness or pain lateral to the larynx
The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...
, and reduced frequency and intensity range.[ Airflow levels during speech may also be increased.] Vocal fold nodules are thought to be the result of vocal fold tissue trauma caused by excessive mechanical stress, including repeated or chronic vocal overuse, abuse, or misuse.[ Predisposing factors include profession, gender, dehydration, respiratory infection, and other inflammatory factors.][
For professional voice users as well as individuals who frequently experience ]hoarseness
A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...
, vocal hygiene practices are recommended for the prevention of vocal fold nodules and other voice disorders. Vocal hygiene practices include three components: regulating the quantity and quality of voice use, improving vocal fold hydration, and reducing behaviours that jeopardize vocal health.[ About 10% of nodules resolve on their own, which is more likely if they are smaller and the onset more recent.] Treatment of vocal fold nodules usually involves behavioural intervention therapy administered by a speech–language pathologist. In severe cases, surgery
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
to remove the lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals.
Types
There is no designated classifi ...
s is recommended for best prognosis
Prognosis (Greek: πρόγνωσις "fore-knowing, foreseeing") is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) or remain stabl ...
. In children, vocal fold nodules are more common in males; in adults, they are more common in females.
Signs and symptoms
One of the major perceptual signs of vocal fold nodules is a change in the quality of the voice. The voice may be perceived as hoarse, due to aperiodic vibrations of the vocal folds, and may also be perceived as breathy, due to an incomplete closure of the vocal folds upon phonation
The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, ''phonation'' is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the defini ...
. The degree of hoarseness and breathiness perceived may vary in severity. This variability may be due to the size and firmness of the nodules. Other common symptoms include difficulty producing vocal pitches in the higher range, increased phonatory effort, and vocal fatigue. There may be a sensation of soreness or pain in the neck, lateral to the larynx
The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...
, which generally occurs because of the increased effort needed to produce the voice.
Acoustic signs
Major acoustic signs of vocal fold nodules involve changes in the frequency and the intensity of the voice. The fundamental frequency, an acoustic measure of voice pitch, may be normal. However, the range of pitches the individual is capable of producing may be reduced, and it may be especially difficult to produce pitches in the higher range. The intensity of the voice, an acoustic measure of amplitude or loudness, may also be normal. However, the individual's amplitude range may be reduced as well. Perturbations or variations in frequency, known as jitter, and in amplitude, known as shimmer, may be increased.
Aerodynamic signs
If the nodules affect the closure of the vocal folds, airflow levels during speech may be increased in comparison to the speaker's habitual levels. However, airflow levels may still fall within the upper limits of the normal range. The degree to which an individual's airflow levels increase seems to depend on the severity of the injury. Subglottal pressure, the air pressure that is available below the glottis and in the trachea to produce speech, may be increased as well.
Causes
Vocal fold nodules are thought to be the result of vocal fold tissue trauma caused by excessive mechanical stress
In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a force it will cause elonga ...
. During phonation, the vocal folds undergo many forms of mechanical stress. One example of such stress is the impact stress caused by the collision between the left and right vocal fold surfaces during vibration. This stress is thought to reach its maximum in the mid-membranous region of the vocal folds, at the junction of the anterior 1/3rd and posterior 2/3rd, the most common site of nodule formation. Vocal overuse (speaking for long periods), abuse (yelling), or misuse (hyperfunction) may produce excessive amounts of mechanical stress by increasing the rate and/or force with which the vocal folds collide. This may lead to trauma that is focalized to the mid-membranous vocal fold and subsequent wound formation. Repeated or chronic mechanical stress is thought to lead to the remodeling of the superficial layer of the lamina propria
The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosae, which line various tubes in the body, such as the respiratory tract, the gastrointestinal tract, and the urogenita ...
. It is this process of tissue remodeling that results in the formation of benign lesions of the vocal folds such as nodules.
There are several factors that may predispose an individual to vocal fold nodules. Activities or professions that may contribute to phonotraumatic behaviors include cheerleading, untrained singing, speaking above noise, and teaching without voice amplification, as these increase mechanical stress and subsequent vocal fold trauma. Gender may be another predisposing factor, as vocal fold nodules occur more frequently in females. The presence of dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
, respiratory infection
Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...
, and inflammatory factors may also act as predisposing or aggravating factors. Inflammatory factors may include allergies
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermat ...
, tobacco and alcohol use, laryngopharyngeal reflux
Laryngopharyngeal reflux (LPR) is the retrograde flow of gastric contents into the larynx, oropharynx and/or the nasopharynx. LPR causes respiratory symptoms such as cough and wheezing and is often associated with head and neck complaints such a ...
, and other environmental influences.
Pathophysiology
Vocal fold nodules often alter the mechanical properties of the vocal folds, which can interfere with their vibratory characteristics. Nodules may increase the mass of the vocal folds, especially along the medial edge where they are typically found. This increased mass may result in aperiodic or irregular vibration, the perception of greater pitch and loudness perturbations, and of increased hoarseness. Nodules may also affect the mucosal wave of the vocal folds by changing the configuration of the vocal fold closure pattern. They often cause incomplete closure of the vocal folds, resulting in an hourglass configuration. The incomplete closure allows more air to escape through the vocal folds, which often results in the perception of breathiness. The degree to which nodules will affect the mucosal wave and vibratory characteristics of the vocal folds depends highly on the size of the nodule. Smaller nodules may still allow the vocal folds to achieve complete closure.
Diagnosis
Diagnosing vocal fold nodules typically includes a comprehensive analysis of medical and voice history, a physical examination of the head and neck, perceptual evaluation of voice, and visualization of the vocal folds.[Johns, M. M. (January 01, 2003). Update on the etiology, diagnosis, and treatment of vocal fold nodules, polyps, and cysts. Current Opinion in Otolaryngology & Head and Neck Surgery, 11, 6, 456-61.] Visualization is considered to be the main method of diagnosis as perceptual evaluation, which includes acoustic and aerodynamic measures, alone is insufficient.[Pedersen M, McGlashan J. Surgical versus non-surgical interventions for vocal cord nodules. Cochrane Database of Systematic Reviews 2012, Issue 6. Art. No.: CD001934. DOI: 10.1002/14651858.CD001934.pub2] Laryngeal videostroboscopy, an imaging technique, is commonly used to view the vocal folds: this procedure can be performed nasally or orally. Vocal fold nodules are most often characterized as bilaterally symmetrical whitish masses, and tend to form at the midpoint of the vocal folds.
Nodules may prevent complete closure of the glottis
The glottis is the opening between the vocal folds (the rima glottidis). The glottis is crucial in producing vowels and voiced consonants.
Etymology
From Ancient Greek ''γλωττίς'' (glōttís), derived from ''γλῶττα'' (glôtta), va ...
, also known as glottal closure, and their presence may lead to an hourglass-shaped glottal closure. Voice problems may result from the presence of vocal fold nodules.[Verdolini, K., Rosen, C.A., & Branski, R.C. (2014). Classification Manual for Voice Disorders-I. New York, New York: Psychology Press.] They are diagnosed based on the presence of perceptual features not explicable by other causes. Such symptoms include: vocal fatigue, breathiness, loss of high pitch notes, lack of vocal control, or increased phonatory effort (i.e. increased effort to produce speech).
Prevention
Regulating voice use
For individuals who work with their voice (e.g., singers, actors, teachers, stock brokers), voice training that includes vocal function exercises (VFEs) may help reduce undue vocal strain. Furthermore, recommendations for voice professionals include warm-up and cool-down exercises for the voice to reduce strain.[ Additionally, using amplification devices, such as speakers or microphones, is recommended for individuals who speak to large, and even small groups or in the presence of background noise.][
]
Hydration
Staying hydrated decreases the pressure that the vocal folds exert on one another by ensuring sufficient lubrication by mucosa, increasing the efficiency of vocal fold oscillation
Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
during speech, and promoting a healthy voice quality
The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, ''phonation'' is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the defin ...
. Consumption of caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...
in large quantities is dehydrating and is therefore implicated in an increased risk of vocal fold nodules.[
]
Lifestyle changes
Behaviours such as frequent throat clearing, shouting, speaking over background noise, and hard crying are associated with an increased risk of developing nodules and other vocal pathologies.[ Furthermore, unconventional voice practices such as speaking in the falsetto register, cause excessive strain and may result in nodules. The avoidance of damaging vocal behaviours may prevent the formation of nodules. ]Tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
, alcohol, certain medications, and recreational drugs
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasur ...
have also been implicated in pathologies of the vocal folds.[ Reducing exposure to these substances has been shown to reduce one's risk of nodules. Other behaviours that are implicated in vocal fold nodules include poor sleeping habits and poor nutrition.][
]
Treatment
The two main methods of treating vocal fold nodules are voice therapy
Voice therapy consists of techniques and procedures that target vocal parameters, such as vocal fold closure, pitch, volume, and quality. This therapy is provided by speech-language pathologists and is primarily used to aid in the management of v ...
(a behavioural
Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as wel ...
treatment) and laryngeal microsurgery (a surgical
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
treatment). Because of general risks of surgery (e.g. scar formation, or those posed by general anesthesia), behavioural treatment is usually recommended first.
Behavioural treatment
Behavioural voice therapy
Voice therapy consists of techniques and procedures that target vocal parameters, such as vocal fold closure, pitch, volume, and quality. This therapy is provided by speech-language pathologists and is primarily used to aid in the management of v ...
is typically carried out by speech–language pathologists. While behavioural treatments methods vary greatly, they are generally effective at improving vocal quality and decreasing size of vocal fold nodules. Complete resolution of nodules through behavioural treatment is possible but unlikely.
Behavioural techniques can be indirect or direct. Indirect approaches focus on improving vocal hygiene, introducing and/or maintaining safe voice practices (thereby reducing opportunities for phonotrauma) and, occasionally, implementing vocal rest
Vocal rest or voice rest is the process of resting the vocal folds by not speaking and singing typically following viral infections that cause hoarseness in the voice, such as the common cold or influenza or more serious vocal disorders such as ...
. Direct approaches involve reducing the physiological strain on the vocal system while the voice is being used (e.g. during speaking or singing), such as by reducing collision forces between the vocal folds, ensuring sufficient pulmonary support while speaking (e.g. by changing the individual's breathing pattern), and optimizing resonance
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscillatin ...
of the larynx
The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...
and other structures of the vocal apparatus
In articulatory phonetics, the place of articulation (also point of articulation) of a consonant is a location along the vocal tract where its production occurs. It is a point where a constriction is made between an active and a passive articula ...
.
Behavioural treatments also vary in delivery model. Traditional therapy distribution (e.g. eight sessions within eight weeks), more intensive approaches (e.g. eight session within three weeks) and remote therapy (i.e. telehealth
Telehealth is the distribution of health-related services and information via electronic information and telecommunication technologies. It allows long-distance patient and clinician contact, care, advice, reminders, education, intervention, mon ...
) have all shown effectiveness in treating vocal fold nodules.
Assessment of outcomes of behavioural treatments also varies greatly. Effects can be measured visually (e.g. by the same methods typically used to confirm the presence of vocal fold nodules: video endoscopy
An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...
and video stroboscopy), aerodynamically (e.g. by measuring parameters such as transglottal pressure and the glottal airflow waveform), perceptually (e.g. by rating the voice in terms of dimensions such as roughness, breathiness, asthenia and strain), in terms of effect on quality of life measures, or using any combination of the above.
Finally, recurrence of vocal fold nodules after behavioural treatment is always a possibility, particularly if nodules were not completely resolved or if skills gained during treatment were not carried-over outside of therapy sessions or maintained after therapy blocks.
Surgery
When behavioural treatments have been deemed ineffective for a voice user, surgical
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
intervention is often considered. Surgical treatments are considered in cases of unresolved dysphonia
A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...
which negatively impacts the patient's quality of life
Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...
. Removal of vocal fold nodules is a relatively safe and minor surgery. However, those who sing professionally or otherwise should take serious consideration before having surgery as it can affect the ability to sustain phonation
The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, ''phonation'' is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the defini ...
, as well as alter the vocal range
Vocal range is the range of pitches that a human voice can phonate. A common application is within the context of singing, where it is used as a defining characteristic for classifying singing voices into voice types. It is also a topic of st ...
. While the patient is subdued under general anesthesia, long thin scissors and scalpels or CO2 surgical lasers might be used to remove the nodules.[ Microsutures are sometimes used to close the incision.][ Vocal rest for a period of 4 to 14 days is recommended post surgery to facilitate healing.][
]
Prognosis
Vocal fold nodules typically respond well to non-surgical/behavioural treatment techniques such as those described in the "Treatment" section. Therefore, if the patient is able to engage in such behaviour modification techniques the prognosis is good (although exact data is not available). If lesions are still present after non-surgical treatment methods, it is likely they are another form of benign
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
vocal fold lesion ( polyp, fibrous mass, cyst
A cyst is a closed sac, having a distinct envelope and cell division, division compared with the nearby Biological tissue, tissue. Hence, it is a cluster of Cell (biology), cells that have grouped together to form a sac (like the manner in which ...
, or pseudocyst
Pseudocysts are like cysts, but lack epithelial or endothelial cells. Initial management consists of general supportive care. Symptoms and complications caused by pseudocysts require surgery. Computed tomography (CT) scans are used for initial ima ...
). The prognosis of requiring surgery would only occur after an exhaustive attempt at non-surgical therapy techniques has been applied.
Epidemiology
Research on the epidemiology of vocal fold nodules in children has suggested that nodules are more common in boys (2:1), in particular boys who are active and scream more frequently. However, in adulthood, women are more likely to have nodules, and are especially likely if they have an outgoing personality or sing frequently.[ The exact prevalence of vocal fold nodules is not known, but it has been reported that 23.4% of children who attended an ]ENT
Ents are a species of beings in J. R. R. Tolkien's fantasy world Middle-earth who closely resemble trees; their leader is Treebeard of Fangorn forest. Their name is derived from an Old English word for giant.
The Ents appear in ''The Lord of ...
clinic for voice hoarseness
A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...
, 6% of phoniatric clinic attendees, and 43% of teachers with dysphonia
A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...
had nodules.
References
External links
How an untreated vocal cord nodule affected one person
at ''The Guardian''
{{DEFAULTSORT:Vocal Fold Nodule
Voice disorders
Vocal fold disorders
Lesion