Types of Voice Disorders
Voice disorders are medical conditions involving abnormal pitch, loudness or quality of the sound produced by the larynx and thereby affecting speech production. These include:
- Vocal Fold Paralysis
- Vocal Dysphonia
- Spasmodic Dysphonia
- Functional Dysphonia
1) Vocal Fold Paralysis
What is Vocal Fold Paralysis?
The vocal folds of the larynx which is a major source of sound in speech, is controlled by the vagus nerve, the 10th of the 12 cranial nerves. By the recurrent laryngeal nerve and the superior laryngeal nerve inside the vagus nerve, the muscles inside the larynx and the vocal folds move together naturally to cause sounds and breathing, and to prevent food from going down through the trachea.
The vocal folds are brought together by the action of laryngeal nerves, so that air pressure builds up beneath the larynx, generating sound through the rhythmic opening and closing of the vocal folds. However, when the nerves are paralyzed, the vocal folds do not open or close properly and remain open, leaving the airway passage and the lungs unprotected. It causes hoarseness and coughing because the food goes down and gets stuck in the trachea.
This condition is called vocal fold paralysis. When only one side is paralyzed, it is called unilateral vocal fold paralysis, and when both sides are paralyzed, it is called bilateral vocal fold paralysis.
However, it is very important to know that laryngeal nerve paralysis for voice disorder therapy is not the only cause for abnormal movement of the vocal fold. There may be other reasons such as:
– A tumor inside the larynx
– Arytenoids dislocation from trauma
– Damage to the joints
– Congenital malformation
– Infection of the larynx
– Scarred vocal fold
Therefore, it is important to find out the exact reason why this has occurred.
How is vocal fold paralysis diagnosed?
Vocal fold paralysis can be caused by many reasons. It is important to examine how far it has developed, whether it can recover, and the time of recovery. Therefore, different evaluations must be performed according to the cause. Brain computed tomography, and brain MRI is performed when necessary, to examine brain disorder brain tumor, a disorder in the central nervous system and the peripheral nervous system. To identify neck tumors or disorders in the blood vessels or nerves, cervical computed tomography is necessary, and sometimes thyroid functional test and ultrasonography might be necessary. Laryngoscopy and laryngeal stroboscopy are performed to identify inborn disorders, inflammatory diseases and functional disorders.
How can vocal fold paralysis be treated?
The treatment of unilateral vocal fold paralysis and voice disorder therapy started a long time ago.
In 1911, Dr. Wilhelm Brunings first started the treatment for paralyzed vocal folds by injecting paraffin to the paralyzed vocal fold muscle. The method of voice disorder therapy was used mainly to treat vocal fold paralysis until the 1970’s, but it is no longer in use due to its side effect of forming granuloma.
Later in 1915, Dr. Erwin Payr first developed the method of operating the thyroid cartilage which was a laryngeal structure. From then on, there was no systematic theory until 1950, and not many operations were performed. After Dr. Isshiki systematically established the operation of the laryngeal structure in 1974, thyroplasty became common. Another laryngeal structure operation is the arytenoid adduction, first performed to 12 patients by Dr. Slavit and Dr. Maragos in 1992. Recently the method of using thyroplasty and arytenoid adduction simultaneously is being attempted.
In 1977, the method of partially cutting off the omohyoid muscle for voice disorder therapy which is connected to the hypoglossal nerve branch and implanting it to the vocal fold muscle (thyroarytenoid muscle) was newly attempted by Dr. Tucker. Namely, it was the method of replacing a paralyzed nerve in the vocal fold with another nerve. However, it is not used commonly because it requires too much time for the vocal fold to recover its function.
Later in 1984, Dr. Ford first attempted the method of injecting collagen into the vocal fold, and in 1991 Dr. Mikaelian introduced the method of using fat transplantation.
The latest operation method in use is the Percutaneous EMG-guided Injection Laryngoplasty developed and presented at national and international conferences by Dr. Hyung-tae Kim, adjunct professor at Catholic University of Korea College of Medicine and current director of Yeson Voice Center. This method involves the injection of artecoll to the vocal cord ligament layer using the electromyogram.
Types of Vocal Dysphonia-
- Vocal Nodule
- Vocal Polyp
- Vocal cyst
- Granulomatus laryngitis
- Reinke edema
- Sulcus Vocalis
- Laryngeal Papillomas
- Laryngeal Cancer
- Laryngopharyngeal Reflux
- Vocal Nodule
Vocal fold nodules are caused by strenuous or abusive voice practices especially in those who use their voice in their profession. In infants, it is very important to distinguish nodules from vocal fold cyst and arrive at proper diagnosis.Symptoms:
Continuous hoarseness and fatigue of the voice are symptoms of vocal fold nodules. Nodules do not cause pain or difficulty when swallowing food. Through a scientific view, a vocal fold nodule developed in the center of a vocal fold can be observed. The nodules are usually formed on areas of the vocal folds that receive the most pressure when the folds come together and vibrate. Vocal fold nodules do not grow over a certain size, and do not cause breathing difficulties.Treatment:
It is important to receive a voice therapy which focuses on eliminating the abuse of the voice and teaches proper use of voice. Nodules are often removed through voice therapy itself, and no surgeries are required. When nodules are not removed through voice therapy, surgical treatments are necessary. Surgeries include laryngo-micro surgery and CO2 laser. Currently, endoscopic microfracture surgery and PDL are performed.
- Vocal Polyp
Like vocal nodules, a vocal polyp is caused by voice abuse. However, it may be caused by a temporary damage or an upper respiratory infection.Symptoms:
Vocal polyps cause the voice to be hoarse, and the symptoms may differ depending on the size and location. In some cases, the symptoms occur broadly and severely, and disseminated polyps may result in breathing difficulties.
Polyps require microlaryngoscopic surgery of PDL to be removed. When they are caused by the abuse of the larynx, voice therapy should be done together.
- Vocal cyst
A cyst is a mass made-up of a collection of material, usually mucus that is surrounded by a membrane. It is found underneath the mucosa, within the superficial lamina propria, the layer that is important for normal voice function.Symptoms:
Cysts generally cause painless hoarseness. The hoarseness results from irregularities in vocal fold closure as well as irregularities in vibration, both the result of the bulk and location of the cyst. In some cases, the voice change may be accompanied by a sensation of a foreign body at the level of the vocal folds, or a feeling of wanting to clear the throat or cough.
Most commonly, a cyst can be removed by Microlaryngeal surgery and Pulsed Dye Laser surgery as well at the same time. It is important to remove the root completely to prevent the recurrence.
- Granulomatus laryngitisCauses:
Intubation granuloma is often caused after a laryngeal surgery, bronchoscope test, or endotracheal intubation.Symptoms:
A granuloma is usually found at the back of the vocal fold over the part of cartilage. At the beginning, the granuloma becomes larger in size, but after certain days, it starts to degenerate. In many cases, the granuloma comes bilaterally, and hoarseness is not severe. It is usually found in females.
Vocal rest and steroid can improve the condition. While the granuloma is growing, antibiotics can be helpful. If the granuloma does not improve after these steps, a laryngeal microsurgery or steroid injection after an incision using CO2 laser may be effective. The recently developed Pulsed dye laser surgery using a laryngoscope can also remove the granuloma under local anesthesia.
- Reinke edema
Reinke’s edema is caused by chronic voice abuse and vocal damage. It is also related to smoking.Symptoms:
Reinke’s edema is one of the chronic laryngitis and its main symptom is continuous hoarsenss. Biopsy of the vocal fold is used to help diagnosis. Reinke’s edema causes the vocal folds to swell giving them a sac-like appearance.Treatment:
The conservative treatment involves removing the source of irritant in the larynx, vocal treatments, and smoking cessation. Surgeries include laryngo-micro surgery using laryngo-micro equipments or CO2 laser which removes the submucosal edema to help restore the normal vocal fold tissue.
- Sulcus Vocalis
Sulcus vocalis is a thinning or absence of a special layer of tissue, which is the tissue covering the vocal cord requires to vibrate in order to produce sound.Symptoms:
Sulcus vocalis causes a characteristic harsh, reedy hoarseness. People with sulcus frequently must exert unusual effort to produce voice, and find it more difficult to be heard over background noise.
Microlaryngeal surgery can be treated to incise the sulcus vocalis, or Injection laryngoplasty can be another treatment option. Recently, Pulsed Dye Laser surgery procedure brings a great outcome of the patients.
- Laryngeal Papillomas
Laryngeal Papillomas are benign epithelial tumors that are caused by infection with the human papilloma virus (HPV) of types 6 and 11. Since the disease is most commonly found in children the disease may be caused by an infant contracting HPV from the mother during vaginal child birth.Symptoms:Adults- In adults the symptoms Laryngeal papillomatosis are hoarseness, or a strained or breathy voice. Size and placement of the tumors dictate the change in the person’s voice. Breathing difficulties may occur but more commonly are found in childrenChildren- In babies and small children the symptoms include a weak cry, trouble swallowing, noisy breathing, and chronic cough. Noisy breathing may be a stridor, which can sound like a whistle or a snore, and is a sign that the laryngeal or tracheal parts of the airway are narrowing.
Yeson Voice Center implemented the Photo Genica SV PDL (Pulsed Dye Laser) from Cynosure Inc. U.S. This implementation is the first domestically, but also used in Asia. This equipment can perform Laryngeal Surgery without general anesthesia using digital laryngoscope. This laser equipment is totally new, high tech laser surgery equipment, which is a Pulsed dye laser Laryngeal Surgery equipment, and it only requires partial anesthesia. This Pulsed dye laser selects and solidifies only blood vessels at vocal band. It does not damage the healthy tissue. It selects and destroys only the abnormal tissue.
- Laryngeal Cancer
Laryngeal cancer is a disease in which cancer cells form in the tissues of the larynx (voice box). Most laryngeal cancer is found in smokers. Smoking is one of the most certain causes for laryngeal cancer. If you are a smoker, it is crucial to quit immediately. Just like in any other cancers, the best way to treat laryngeal cancer is early diagnosis.Symptoms:
Sore throat or pain when swallowing, voice change, ear pain, etc.Treatment:
There are 3 types of standard treatment for patients with laryngeal cancer.
– Radiation therapy : uses high-energy x-rays or other types of radiation to kill cancer cells.- Surgery : removes all parts where cancer has developed.- Chemotherapy : uses drugs to kill cancer cells.
- Laryngopharyngeal Reflux
Laryngopharyngeal reflux (LPR) is the inflammation of the larynx or pharynx (throat) caused by stomach acid or food backing up into the esophagus.Symptoms:
The symptoms of laryngopahryngeal reflux are the following:
– Chronic hoarseness- Frequent or dry cough- Sensation of a lump in the throat- Difficulty and pain swallowing food
Some people may also have heartburn or have phlegm in the throat. If you have above the symptoms, and especially if you are a smoker, It is recommended to see an otolaryngologist and get a checkup for LPR. If possibilities of LPR are found, then you will first have your throat examined and then the larynx and the deep parts of the throat. If the larynx and throat are swollen or inflamed, then a special examination or proper medical treatment will be required.
Medication prescriptions will differ according to the person; your doctor will suggest to you the most adequate medications.
The general treatments for LPR are
- Diet modifications to reduce reflux.
- Medications to restrain stomach acid.
- Surgery to prevent reflux.
Anyone who has LPR must change his diet and body posture. He must also take appropriate medicine. At times, antacids such as Mylanta, Almagel, Amphojel, and Curan, or drugs that accelerate the gastroesophageal sphincter muscle and prevent reflux like Cisapride and Motilium can be used. Drugs that strongly restrain stomach acid secretion like Pariet and Omeprazole can also be used.
However, these drugs must always be prescribed by a medical specialist.
3) Spasmodic Dysphonia
Spasmodic dysphonia is a voice disorder caused by the excessive tension in the laryngeal muscles. Individuals with spasmodic dysphonia have breaking voices and face difficulty to start and continue communication.
The number of people suffering spasmodic dysphonia of unknown origin in U.S. ranges from 50,000 to 100,000 based on the U.S .statistics. Korea has no accurate statistical data on spasmodic dysphonia, but the number is assumed to be from 5,000 to 10,000.
Spasmodic dysphonia is often classified according to the age the symptoms develop. When symptoms develop before the age of 20, it is called infant type. When symptoms develop after the age of 20, it is called adult type.
Many doctors thought that mental problems were the cause of spasmodic dysphonia, because symptoms would get better when taking alcohol or tranquilizers, or get worse when being stressed or talking on the phone.
In the 1980’s, as researches of the cranial nerve brought the thought that the cause of spasmodic dysphonia was the abnormal spasm of the laryngeal muscles due to the inharmonic function with the basal ganglia where the integration of the central nerves takes place.
However, Dr. Ludlow, from the National Institute of Neurologic Disorder (NINDS) of National Institute of Health (NIH), proved that the cause of spasmodic dysphonia is the abnormal nerve system in the Nucleus Tractus of Solitarius, so patients lose control of their vocal fold muscle which makes it hard to talk and breaks off sounds.
Types of Dysphonia
Spasmodic dysphonia is classified according to each symptom and characteristic.
- Adductor type: approximately 80%- glottis
– dystonia tremor
– adductor type with tremor
- Abductor type: approximately 4%
- Mixed type: approximately 11%- Abductor-adductor type (abductor type with symptoms of adductor type)
– Adductor-abductor type (adductor type with symptoms of abductor type
- Respiratory dysphonia: approximately 2%. The term ‘paradoxical vocal fold motion’ is more often used today.
Adductor spasmodic dysphonia is the most common type which involves spasm of the muscles that close the vocal folds. Glottic type is relatively common. Its symptoms develop from improper and irregular movements of vocal cords. Glottis type reacts better than Supraglottic type to botulinum toxin (Botox).
Electromyogram specialty of Spasmodic Dysphonia
|First, you will receive an acoustic vocal test. Then a test will be performed to measure the muscular spasm of vocal cord when speaking, and examine excessive spasm or tremor of the laryngeal muscle using a laryngoscope.|
|Next, we will measure the changes in the basic vocal frequency with acoustic tests and observe the vocal waveform through spectrogram. Then we run the electro-glottography test and measure the resistance of the larynx through the aero dynamics test.|
|Laryngeal stroboscopy examines the movement of the larynx, and the laryngeal electromyography helps find the abnormal movements of the larynx and vocal fold muscle. Using the laryngeal electromyography we can find pathophysiological problems and estimate the possibilities of recovery by checking laryngeal reflex.|
High speed vocal fold filming system
|We also use thehigh speed vocal fold filming system which was introduced for the first time in Asia, to find the exact place of spasm. Botox injection, where a small quantity of Botox is directly injected to the affected muscle, enables the voice to stay in good condition without the period of hoarseness.|
Currently, there are three types of treatments for spasmodic dysphonia; medicinal treatment, surgical operation, and botulinum toxin (Botox).
uses anti-choline type drug, tranquilizer, baclofen, and dopamine antagonist, etc. However, medicinal treatment has serious side effects and is used only for serious myotonic disorders. Medicine treatment for spasmodic dysphonia is just secondary treatment.
- Hemilaryngectomy: Dedo reported the first treatment in 1976. It requires amputation of vocal fold nerve so it prevents the excessive contraction of the vocal cord. However, there is a 64% possibility of a relapse within 3 years.
- Thyroid chondroplasty: It is a method of incising the front part of the thyroid cartilage and widening the vocal fold to reduce tension. It prevents excessive closing of the vocal fold even when spasm occurs. However, the muscle tension receptors inside the vocal cord can bring the voice back in bad condition over time.
- Laser vocalis muscle cordotomy: Using laser, it removes a part of the vocal muscle to make the muscle thinner.
- Nerve stimulator transplantation: Transplants nerve stimulator of the vocal cord to prevent excessive contraction of the vocal cord. This type of treatment does not cure completely, and it may relapse within a few months or a few years based on long period tracking.
All surgical methods do not bring complete treatment, and long-term observations show that symptoms return within months or years.
The injection of botulinum toxin (Botox)
The injection of botulinum toxin (Botox) is currently the most effective treatment. However, this is a temporary treatment which improves the voice for a period of three to six months after which the voice symptoms gradually return. The treatment requires continual injections to maintain a good speaking voice.
Until a few years ago, the treatment involved injecting certain muscle in the vocal fold or injecting in one side of the vocal cord. In this case there was no study of the effect on the cerebrum, so the other side of vocal fold tries to match the balance and creates over spasm on the other side. Therefore, this treatment might make the vocal cord worse due to the side effect.
So, the treatment has changed to multiple laryngeal muscle injections with Botox. The treatment normalizes the voice by injecting small amounts of Botox in the abnormal laryngeal muscles. This treatment extends the period of having a good voice and minimized the term of hoarseness after Botox injection, helping the normalization of voice by cranial reflex rehabilitation.
Multiple laryngeal muscle injection is currently being performed at Yeson Voice Center and is bringing very satisfactory results for our patients.
What is Botox?
Clostridium botulinum is a bacterium that produces botulism, the toxin botulin. This bacterium produces 7 different types of botulin toxin which can paralyze the myoneural system. These 7 types of toxin are called botulinum toxin (Botox) and are labeled as A, B, C, D, E, F, and G types.
The Structure of Botox
Each type of Botox consists of 2 polypeptide chains by S-S bond. The large cane-like polypeptide is called the heavy chain, and it is the same in all 7 types. The small cane-like polypeptide is called the light chain, and the forms are different according to the vernation type.
The History of Botox and its Medical Uses
Development and use of botulinum toxin as a possible bioweapon began at least 60 years ago. Botulinum toxin is the most poisonous substance known. It is about 6 million times stronger than the poison of a rattlesnake, and a single gram of crystalline toxin, evenly dispersed and inhaled, would kill more than 1 million people. Consequently, researches on the use of botulinum toxin as a bioweapon began..
The US biological weapons program first produced botulinum toxin during World War II at Port Dittrick of Maryland. Because of concerns that Germany had weaponized botulinum toxin, more than 1 million doses of botulinum toxoid vaccine were made for Allied troops preparing to invade Normandy on D-Day. The US biological weapons program was ended in 1969-1970 by executive orders of President Nixon. However, Dr. Edward Schantz of the food research institute and the Erick Johnson Research Center and produced the toxin for research activities.
For 10 years, Dr. Alan Scott used botulinum toxin in animal experiments, and in 1968 he used it for the first time in humans to treat strabismus. Later, Botox received FDA approval for treatment of strabismus, torticollis, and spasmodic dystonia.
In 1984, Dr. Blitzer first used botulinum toxin for spasmodic dysphonia, and it is still used for treatment.
- The Fine Art of Making Poison” Tom Waters, Discover, Aug, 1992. 2. Botulinum Toxin as a Biological Weapon, JAMA Vol. 285 No. 8, Feb. 28, 2001.
The Medical Uses of Botox and its History
In the late 1960s, Dr. Alan Scott of Smith-Kettlewell Institute and Dr. Edward Schantz, of Wisconsin made a research about a substance that would relax the eye muscle which causes strabismus. As a result, they developed the botulinum toxin type A as a treatment medicine for blepharospasm, facial spasm, and various dystonias
Allergan Inc (U.S) produces botulinum toxin type A by the name ‘Botox’ and type B by the name ‘Myobloc.’
In 1989, Botox was approved by the US Food and Drug Administration (FDA) for the treatment of blepharospasm, and in 2000, both Botox and Myobloc were approved for the treatment of cervical dystonia. Currently, they are used for treating various types of dystonia.
Mechanism of Action of Botulinum Toxin
|The part where the muscle and nerve join is called ‘neuromuscular junction,’ and it is where the signal from the nervous system releases ‘acetylcholine,’ a chemical deliverer that is stored in bubble-like forms at the nerve ends.|
The Inner Structure of
|In the nerve endings, there are various types of proteins that release the acetylcholine stored inside the synaptic vesicle and allows it to fuse with the nerve endings. The proteins include SNAP-25, VAMP, and syntaxin. Botulinum type A and E cleave SNAP-25, and types B, D, F, and G cleave VAMP, while type C1 cleaves syntaxin and SNAP-25.|
|Botulinum toxin intentionally paralyzes the neuromuscles. The injected botulinum toxin enters the heavy chain of the muscle and fuses with the nerve endings.|
|The injected botulinum toxin fuses with the nerve ending and goes inside. Then the botulinum toxin cleaves SNAP-25, the protein inside the nerve ending, and blocks acetylcholine release.|
|When acetylcholine is not released any more, the nervous signals cannot be delivered to the muscle. The muscle will not contract, and will have chemical paralysis. When time passes, new sprouts will grow at the nerve endings. This is called ‘sprouting.’|
|The newly sprouted nerve joins the muscle to form a neuromuscular junction, removing the effects of Botox.|
With the general amount injected, Botox cannot bring a permanent effect. When large amounts are injected into the muscle, the muscle will weaken more than expected. However, this is not permanent, and the action in the neuromuscular junction will happen again due to the regeneration of the nerves.
Some may think that Botox injection for spasmodic dysphonia might weaken the vocal fold muscles, but this is not true. The amount of Botox injected in the vocal fold is about 1/50-1/100 of that injected for cosmetic treatments. Therefore, it is wrong to think that Botox weakens the vocal fold muscles.
In 1984, Dr. Blitzer first used Botox to treat a patient with spasmodic dysphonia, and there were no reports of vocal fold muscles being weakened until now. In 1996, Dr. Hyung-Tae Kim of Yeson Voice Center performed the percutaneous Botox injection guided by electromyogram for the first time in Korea, and no symptoms of vocal fold muscle weakening have been found up to now.
Currently, Botox is used to treat spasmodic dysphonia, facial spasm, blepharospasm, hyperhidrosis, migraine, and other myotonus disorders.
4) Functional Dysphonia
Functional dysphonia is the abnormal use of voice despite normal anatomy and function of the vocal folds and the larynx which produce the voice and the pharynx and mouth which produce resonances. This condition can be related to the abuse or misuse of voice or habituation of compensatory techniques developed from the condition of the larynx.
Functional Dysphonia is often classified into 5 types.
– conversion aphonia
– habitual hoarseness
– inappropriate falsetto
– vocal misuse/abuse syndrome
– postoperative dysphonia
– relapsing aphonia
Symptoms of Functional Dysphonia
Mutational falsetto under a normal laryngeal system causes the voice to be high-pitched, weak, and thin like the voice of a female. The voice is easily fatigued, and difficult to sing.
The voice tone stays high, monopitched and it is difficult to make low-pitches. High-pitched songs cannot be sung.
It can be classified by two different factors; functional & organic.
Most of the functional factors are caused by psychological problems. Young males of pubertal age fail to accept their adult role or suffer emotional stress from the changes of adolescence and raise their sounding pitch.
Most of the organic factors are caused by the abnormality in the vocal membrane. Contractions or scars in the mucosal membrane or the underdevelopment of the larynx cause the focal folds structure to become like a female’s.
Diagnosis of Functional dysphonia
When functional dysphonia is caused by functional factors, the vocal folds appear normal on laryngoscope or laryngeal stroboscopy. The outer laryngeal muscles are excessively used to make a sound, and the larynx elevates. In organic factors, you can notice the abnormalities in the mucous membrane or the underdevelopment of the larynx and the vocal folds.