also known as Laryngeal Dystonia, is a voice problem in which the speech becomes strangled and broken. Often wrongly diagnosed as an E.N.T problem, it is actually a neurological disorder and can usually be treated effectively with Botox.

Information About Botox

Other sources of information

Links to other sites.

Some Advice and Information About SD and Botox Treatment

Spasmodic dysphonia (SD) is considered a type of focal dystonia, namely, laryngeal dystonia. The exact cause of this dystonia is currently unknown, but is thought to involve a region in the brain called the basal ganglia. This area of your brain is sending incorrect messages to the muscles controlling the movement of your vocal cords, causing them to contract inappropriately. Briefly, if you have adductor-type SD, the muscles close your vocal cords too tightly and if you have the abductor-type the muscles open your vocal cords when they should be closed. Some individuals have mixed SD, or characteristics of both adductor- and abductor-type. Botulinum toxin (Botox) might minimize the symptoms of SD when injected into muscles involved with your disorder. This page will provide you with some information about how Botox works, the general technique of the botulinum toxin injections, as well as some of the possible complications.

The diagram shows a cross section of the vocal cords, viewed from above. For the most common type of SD, the thyroarytenoid muscle contracts too strongly, resulting in a strained voice. This is the muscle that is injected with Botox.

The arytenoid is a small cartilage attached to the rear of the vocal cord. It rests on another piece of cartilage called the cricoid.

When breathing or speaking, the air passes through the region between the cords.

General Information About Botox

The effect of the botulinum toxin is to weaken the involved muscles. Although the 'problem area' for dystonia appears to be at the base of the brain, we are only able to treat the disorder by injecting the involved muscle. Therefore it is important to remember that Botox does not treat the cause of dystonia, but only provides temporary symptomatic relief. When the muscle is weakened, even though it is receiving abnormal signals from the brain, it cannot respond as strongly as before. This weakness provides the relief patients experience with Botox treatments.

During the Botox injection, you will lie down on an examination table with your head extended back over a pillow. For adductor-type SD, a local anaesthetic is injected first so that the sensitive areas near the vocal cords is not stimulated when the Botox needle is placed in the muscle. The Botox is injected through a very small needle, which is connected by a wire to an electromyography (EMG) machine that records the activity of the muscle. The placement of the needle into the dystonic muscle is verified by the electrical signals shown on the EMG machine. At that point, through the same needle, the medication is injected. There generally is minimal discomfort associated with the injection. The entire procedure takes just a couple of minutes.

Some patients may cough up some blood-tinged sputum during the first 24 hours after the injection. A small amount of bleeding, no more than a drop or two, occurs when the needle is inserted into the muscle, and this is what can appear in the sputum. Your neck may be slightly sore for a day or two from having the needles inserted, but this usually passes without any intervention needed.

You may begin to notice the effects of Botox around 12-24 hours after the injection. The effect is almost always noted by 48-72 hours and the full effect is established usually by one week, but sometimes as late as two weeks. Once the full effect is achieved, it slowly begins to wear off, although it is not noticeable in most cases for six to ten weeks.

Botox prevents the release of the neurotransmitter at the connection between the nerve and the muscle, causing weakness of the muscle. Over time, the connection between the nerve and the muscle grows back, and therefore, the effect of Botox is temporary. It generally lasts from 6 weeks up to 6-7 months. In most, the time between Botox injections is about three to four months.

Since each muscle in each individual is different, the first one to three injection doses are calculated by estimating the severity of the dystonia. Sometimes too little is given and relief is minimal. Sometimes, if an individual patient is very reactive to the botulinum toxin, an exaggerated response leading to significant weakness can be seen. It may take a few treatments to get the dosage right for each person.

Possible Complications from Botox Injection

There are two general complications associated with Botox injections:

• Antibody formation to the botulinum toxin

• An exaggerated response to the botulinum toxin.

Antibody formation is noted only with higher, frequent doses of Botox administration and is not generally a problem with patients who are receiving the medication for laryngeal dystonia.

The second effect, an exaggerated response to the medication, varies in terms of its effect by which set of muscles is injected:

Adductor spasmodic dysphonia: In this more common type, the muscles that bring the vocal cords together are the ones that are injected. If there is an exaggerated response to Botox the vocal cords will not be able to get together during speech and swallowing. This results in a breathy voice or even in an inability to generate any voice at all. In addition, if the vocal cords do not get together during swallowing, some patients will experience choking when swallowing liquids. If swallowing problems occur, they are usually with handling liquids more than solids.

Abductor spasmodic dysphonia: For this type of SD, the muscles that are injected are the muscles that move the vocal cords apart In the event of an exaggerated response, the vocal cords would not be able to move apart, therefore causing you to have difficulty breathing.

The above information provides a general description about the effect of treatment with botulinum toxin. Although severe complications are not common, it is important that you know what they are so that you can be an active participant in your treatment. The more informed you are, the better you will be able to respond should a problem occur.

Other Sources of Information

The Dystonia Society

46/47 Britton Street

London EC1M 5NA

0208 490 5671

The Dystonia Society produce a regular newsletter and you can get help and advice from their Welfare advisor. They can also give you details of the support group in your area.

National Spasmodic Dysphonia Association

One East Whacker Drive

Suite 2430

Chicago, IL 60601-1905

Although based in the USA, the NSDA is happy to have members in the UK. Their quarterly newsletter deals solely with SD.

Here are some of the key website addresses.

http://www.dystonia-foundation.org/NSDA/

http://www.bgsm.edu/voice/survey_sd.html

stevemottram@blueyonder.co.uk

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