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Normally the vocal folds are able to open and
close symmetrically. With these two motions, they accomplish three tasks: open
to allow breathing, close to prevent food from entering the trachea (windpipe)
when one swallows, and close to produce voice with air from the lungs. .)
When one vocal fold is
paralyzed, the larynx is unable to completely close. Thus breathing is usually
normal, since it depends on the vocal folds being able to open. However, people
may find that they occasionally cough or choke when swallowing, particularly
when swallowing liquids. The most noticeable symptom is the dramatic voice
change: the voice become hoarse, breathy and weak. Speaking at loud volume or
over background noise becomes very challenging and effortful.
Some cases of vocal fold
paralysis resolve on their own, although it may take weeks to months. In other
cases, it is almost always possible to achieve a normal or near normal voice
using voice therapy alone or in combination with various types of
surgery. No treatment should be undertaken until a thorough search for the cause
of the problem is done. Sometimes, this will turn up nothing obvious. In such a
case, the cause is deemed “idiopathic,” which simply means of unknown cause.
Up to one-third of cases of vocal fold paralysis may turn out to be idiopathic.
Conditions that must be
eliminated as possible causes include lung cancer, particularly if the paralysis
is on the left, and thyroid cancer.
Treatment must be individualized for
every patient. Treatment depends upon the cause and duration of the paralysis,
and the extent of disability it causes. In some cases, an additional diagnostic
test called electromyography
is recommended. This test may provide information about the likelihood that the
nerve will recover on its own. Therefore, it can sometimes play an important
role in treatment decision. The goal of treatment is to improve vocal fold
closure, because all of the symptoms caused by vocal fold paralysis are due to
incomplete vocal fold closure. Difficulty breathing is the most concerning
complication of surgical treatment. Usually, this complication can be safely
avoided, but this should be carefully discussed with your surgeon. A very brief
summary of treatments is presented below.
Voice therapy
consists of exercises and techniques to help in vocal fold closure. Under
certain conditions, other muscles can be used to increase closure. The voice
therapist will teach you to take advantage of these. Unlike the surgical
treatments, there is no risk to the airway with voice therapy. In cases where
the gap between the paralyzed vocal fold and the working one is small, and
sometimes in cases where the paralyzed vocal fold recovers only partially, voice
therapy alone may be enough to achieve normal voice. Read
more about specific goals and techniques of
voice
therapy for unilateral vocal fold paralysis.
Injection laryngoplasty
is an operation that consists of injection of a material to add bulk to the
paralyzed vocal fold so that it can make contact with the working one. The
injection is done through the mouth, so that there are no scars, and usually
requires general anesthesia. Traditionally, the material injected was Teflon,
but experience has shown that it may cause benign growths called granulomas in a
substantial number of cases, which can further damage voice and even narrow the
airway, making breathing difficult. As a result, Teflon is generally avoided
nowadays. Alternatives include collagen, fat from elsewhere in the body,
processed connective tissue and other, newer substances. None of these are
permanent, and they gradually re-absorb. This is not to say that the voice
result cannot be permanent, as there are other variables involved. Speak to your
physician about the details of the operation and the specific features of the
various materials.
Medialization
laryngoplasty describes
an operation to implant a small piece of synthetic material, which is permanent
(although removable) into the larynx. This serves to bring the vocal fold closer
to the midline (medialize the vocal fold). It is generally performed under a
local anesthetic
in the operating room,
though a small incision on the neck over the larynx. It may be combined with a
procedure known as arytenoid adduction, which rotates the arytenoid to
accomplish the same thing.
Reinnervation
is surgery aimed at providing an alternate nerve supply to the vocal fold. It is
not expected that this will cause the vocal fold to move again, but rather, that
it will restore tone and bulk to a flaccid (limp) vocal fold. Observations have
suggested that this may be enough to achieve a good voice result. Reinnervation
is currently an investigational therapy, and is not used routinely in most
centers.
Because there are many
options in the treatment of vocal fold paralysis, it is important to have a
r
detailed discussion of your condition with your physician. In
most cases, substantial improvement in laryngeal function can be achieved with
treatment. There is no reason to endure the symptoms of unilateral vocal fold
paralysis.
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Bilateral
Vocal Fold Paralysis
When both vocal folds are paralyzed, they are usually immobilized close to the
midline. Thus, closure is usually adequate, permitting acceptable voice and
swallowing. However, breathing is usually very difficult. This difficulty
increases with effort, and people with this condition may find that they are
severely restricted in how far they can walk, or in how heavy a load they can
carry. Often there is a wheezy noise when breathing, which can cause this
condition to be mistaken for asthma. Asthma that fails to improve with
appropriate medicines and inhalers requires that a physician examine the larynx
and vocal folds.
Bilateral vocal fold
paralysis almost always has an identifiable cause – it is rarely
“idiopathic” or unknown. Causes include stroke or other neurologic condition
(especially a childhood condition known as Arnold-Chiari malformation), thyroid
cancer, or surgery such as major brain surgery or thyroidectomy.
The main issue in the
treatment of bilateral vocal fold paralysis is whether or not the vocal folds
are far enough apart to allow safe breathing. In many cases, the safest initial
treatment is a tracheostomy – a breathing hole directly into the windpipe –
to guarantee the airway until other plans are made.
There are procedures to allow
adequate airway and permit removal of the tracheostomy. However, all of these
may cause some deterioration of voice quality, and sometimes, may create
problems swallowing. This is because these procedures (such as arytenoidectomy
and cordotomy) necessarily increase laryngeal opening.
Treatment of bilateral vocal
fold paralysis often requires making some difficult choices. As is true in all
voice disorders, nothing can take the place of a detailed discussion with your
treatment team.
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Spasmodic
Dysphonia
Spasmodic dysphonia is an area
of special expertise at the Institute. Spasmodic dysphonia is a frustrating,
chronic condition for which no cure is currently known. However, it is only
rarely associated with other diseases. In most cases, treatment can
substantially improve symptoms, often resulting in a near-normal voice. Because,
in the end, the affected person is the best judge of his or her voice function,
honest and open communication between the doctor and the patient is essential in
getting the most out of treatment and overcoming the disorder. At The Voice and Swallowing Institute, we believe that providing patients with information about this
complex disease is an essential part of treatment. We’ve provided a great deal
of information about the disease and its treatment in the document linked here,
to help our patients discuss the best treatment.
Fact
Sheet about Spasmodic Dysphonia 
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FAQs
about Botulinum Toxin treatment of Spasmodic Dysphonia
What dose of botulinum toxin should I receive?
Should I be receiving unilateral or bilateral
Botulinum toxin
injections for my SD?
What happens if I do not get treatment?
What are the common complications?
What
about surgical treatment for SD?
What dose of botulinum toxin should I receive?
There is no standard
Botulinum toxin dose. The dose for each patient with SD has to be
customized for the patient due to the severity of his or her SD, the patient's
voice demands and response to Botulinum toxin. The most common doses range
from 1.0 to 2.5 units placed in the right and left vocal fold muscles for the
treatment of AdSD. The range for a unilateral injection for AdSD is
typically from 2.5 to 10 units.
Back to FAQ index
Should I be receiving unilateral or bilateral Botulinum toxin
injections for my SD?
Once again, there is no
standard rules for injecting Botulinum toxin regarding dose or number of
locations. Most commonly, bilateral injections are done for adductor
spasmodic dysphonia. This is based on the notion that the disorder is bilateral
and symmetric. However, in certain patients a unilateral injection may be
preferable to minimize side effects. For AbSD, it is typical to inject
either one side only or one side with a large dose and the other side a small
dose. The patient will then return approximately three weeks following this
procedure for a repeat injection, depending upon the response to the first
injection.
Back to FAQ index
What happens if I do not get treatment?
Available treatments for
both forms of SD are able only to alleviate symptoms. Opting not to be treated
has no effect on the underlying central nervous system disorder. Patients should
only continue with treatment if they feel it is of benefit to them.
Back to FAQ index
What are the common complications?
Most complications of
treatment are the result of either inaccuracy of injection or inappropriate
dosing of botulinum toxin.
If an injection is not well
placed, the toxin may have no effect, or it may be reduced. This can be
corrected by repeating the injection.
Difficulty swallowing is
probably the most common side effect. Since the larynx lies next to the entrance
of the esophagus, and since laryngeal muscles are small and located fairly deep
within the neck, toxin may inadvertently reach the esophageal or pharyngeal
muscles. Weakening of these muscles, when added to the weakening of the vocal
folds that results from treatment, can result in altered or impaired swallowing.
Some temporary change in swallowing is reported by up to 17% of patients
treated. In the vast majority of cases, this is more of an inconvenience than a
danger. However, it is possible to impair swallowing more severely, and even
theoretically to cause a lung infection from food entering the trachea
(windpipe). Because the effect of botulinum toxin is temporary, it is usually
necessary only to exercise caution while eating or drinking until the situation
returns to normal. This is usually a matter of days or weeks, although in very
rare cases, the problem may persist for the entire three months that the toxin
has effect. Difficulty with swallowing (especially liquids) following
botulinum toxin injection is often most noticeable with the first injection and
may decrease with subsequent injections.
Infection as a result of
botulinum toxin injection performed in the office with normal attention to
cleanliness and sterile technique has not been reported.
Minor bleeding and bruising
at the injection site may occur, especially in those patients who take aspirin
or blood thinners. Serious bleeding has not been reported.
There are side effects
specific to each type of SD as a result of over-dosing the affected muscles.
Because botulinum toxin has a very pronounced effect for the first several days,
some minor unwanted effects are often seen following injection. In AdSD, these
consist of a soft, breathy voice and difficulty when drinking liquids. Both of
these occur because the treated vocal folds are not able to come together
completely. In AbSD, there may be some breathing restriction because the treated
vocal fold is not able to move aside fully. Administering too much toxin results
in these effects becoming more pronounced and lasting longer. Obviously, great
care is used in the treatment of AbSD so as to avoid breathing difficulties.
Side effects can be
minimized and sometimes even eliminated by altering dose or injection pattern
feedback. Information from the patient's experience with the previous injection
is essential in making the necessary adjustments and each new injection should
be preceded by a discussion between patient and physician about the effects of
the previous one.
Back to FAQ index
What
about surgical treatments for SD?
Surgery for SD, like surgery for all dystonias, is a second-choice
treatment, used in those cases in which botulinum toxin treatment is, for one
reason or another, not possible, ineffective or poorly tolerated. This is
because in the past, a disappointingly large number of patients have had a
recurrence of symptoms months to years after surgery. In this respect as well,
surgery for SD is like surgery for other dystonias.
The idea behind surgery for
SD is the same as the one behind botulinum toxin treatment: the weakening of
muscles that spasm. Surgeons initially cut or crushed the nerve to the vocal
fold, called the recurrent laryngeal nerve. Despite encouraging initial results,
about two-thirds of patients developed symptoms of SD again within three years.
Furthermore, one vocal fold remained paralyzed by this procedure, a condition
that has its own drawbacks (link to Vocal Fold Paralysis). Surgeons have also
tried cutting the secondary nerve to the larynx, known as the superior laryngeal
nerve; thinning the muscle of the vocal fold (myectomy); and manipulating the
larynx so that the vocal folds lie farther apart (lateralization thyroplasty) or
are under less tension (anterior commissure release). None of these techniques
has resulted in satisfactory long-term control of symptoms.
Back to FAQ index
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For
Further Information about Disorders of the Larynx
Patient
Associations & Support Groups
Relevant
Medical Journal Articles
-
Botulinum toxin management of spasmodic dysphonia (laryngeal
dystonia): a 12-year experience in more than 900 patients. Blitzer
A, Brin
M
F, Stewart
CF. Laryngoscope 1998 Oct 108:10:1435-41.
- Botulinum toxin: basic science and clinical uses in otolaryngology.
Blitzer
A, Sulica
L. Laryngoscope 2001 Feb 111:2:218-26.
-
Botulinum toxin. National Institutes of Health Consensus Statement
1990 Nov 12-14:8:1-20.
Pharmaceutical
Companies
Because botulinum
toxin use in the United States
for the treatment SD
is not FDA-approved, the manufacturers are not permitted to
discuss information related to this use. Nevertheless, general
information is available from each company.
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