The following article has been written by Lucy Hicklin FRCS ORL H&N, Consultant ENT surgeon with a special interest in voice problems.
"What is wrong with my voice?" As an ENT surgeon with a special interest in voice problems, this is a question I am often asked.  In some patients the answer is very simple and can easily be diagnosed; however some patients may have seen many doctors and had lots of different treatments with no response.  Often the problem will have been going on for some years and in the end the patient is left feeling that they will never find an answer.  Many of these patients will have a condition called laryngeal dystonia (LD) or spasmodic dysphonia.  This is a rare condition affecting the voice where people experience spasms in the vocal cords when they try to speak.  

Initially it usually only affects the voice when speaking and people can sing or shout normally. People with this condition notice that when they are very relaxed the voice is much better and when they are stressed or feeling down the voice is worse.  This is the reason why this condition is often mistaken for stress related muscle tension problems.  Excess muscle tension can affect the voice in a similar way, but it usually improves when the stressful situation improves and also usually gets a lot better with speech therapy.  Whilst people affected by LD will sometimes have had a stressful event before the problem started, the condition doesn’t get better when the stress goes away, and there is also very little response to speech therapy.  

Types of Laryngeal dystonia

There are two main types of LD; the more common is Adductor laryngeal dystonia where the vocal cords shut tightly together when trying to speak.  This leads to a strained, strangled voice and is present in about 80% of people with the condition.  In Abductor LD, the spasm is in the muscle at the back of the voice box that holds the vocal cords open.  This means that when the person goes to speak the vocal cords can’t close and the voice is very weak and breathy and parts of the words will disappear. This happens in about 15% of people with LD; the other 5% have a mixture of the two.

Some people with LD will also have another focal dystonia such as blepharospasm (eyes closure spasms), cervical dystonia (neck muscles spasms), writer’s cramp (spasm in the hand muscles when trying to write) or some form of tremor.  Some will have another family member that has had similar problems.  Most people will only have the voice problem and be the only member of their family that has the problem.  This can make the condition more difficult to diagnose, as there are fewer clues.   Often it is quite a relief when the diagnosis is made because then the person is able to understand what is going on and has the opportunity to have some treatment.  Many of our patients find it helpful to talk to other patients with similar problems, which they are able to do either through the Dystonia Society or by meeting other affected people in the waiting room in the clinic.

Treatment of laryngeal dystonia

The most effective treatment for LD and other focal dystonias is injection of botulinum toxin (BTX) into the affected muscles.  This treatment sounds quite scary but in reality it usually takes only minutes to do and is not nearly as uncomfortable as people expect.  For LD the injection is usually done through the skin of the neck with the patient awake.  The muscle is located using a special needle attached to an EMG machine.  The needle is very thin and flexible like an acupuncture needle.  When the needle is in the muscle we get the patient to make a sound, this activates the muscle and the tracing on the EMG machine changes.  That lets us know that the needle is in place and we can then inject the BTX through the same needle.  The effect of the BTX is not normally felt for 24-48 hours after the injection.  When it starts to work the voice becomes much easier to produce because the muscle cannot contract so tightly.  In many cases the voice is a little weak at the beginning of the treatment but as the days go by the voice strengthens and in most people comes back to near normal.  The effect of the injection will normally last for 3-4 months and then the spasm will tend to come back.  In some of our patients however, after a few years of injections, they have needed treatment much less frequently and may only need to come every 9-12 months.  Some patients will experience mild difficulty with swallowing (particularly liquids) in the first few days or weeks following the injection.  This is rarely too much of a problem and can usually be overcome with a few simple strategies.  

Some patients do not like having injections and have asked about surgery for the condition.  There are quite a few operations that have been invented for SD.  As with operations for other dystonias, they tend to stop working after a few years and the patient has to go back to having injections anyway.  The one currently popular in the UK is a laser procedure to weaken the muscle that causes Adductor SD.  It is quite simple to do but what we don’t know is how long the procedure will last, and afterwards, if it does fail whether the injections will work as well.  For these reasons most people still opt to have injections.

What to do if you think you have laryngeal dystonia

What can you do if you think that you have LD?  The first thing to do is to ask your GP to refer you to your nearest voice clinic.  This is the clinic that is most likely to give you the correct diagnosis.  As LD is so rare many ENT doctors will never have seen a case so seeing a general ENT clinic is not a guarantee of getting an answer.  To find your nearest voice clinic you can contact the British Voice Association who keep a list of all the voice clinics in the UK.

One big difficulty people face is finding a clinic to do the injections.  There are only a few people in the country who do them.  Currently I am doing a national survey to try and identify all the injectors so that we can better advise patients when they enquire about treatment.  When it is available we will be sharing the information with the Dystonia Society, so that newly diagnosed patients can visit the clinic closest to them.  I have been running a clinic for the past 10 years at St Georges Hospital in London with my colleague neurologist, Dr Marie-Helene Marion who is a world renowned expert in botulinum toxin treatment for dystonias.  In our clinic we see many interesting patients of all ages, some of whom more than one dystonia.  We find that working together is really helpful to refining techniques and as a result we have developed some new injections for more unusual dystonias in the neck.  Most of our patients have very straightforward problems that are relatively easy to treat.  However because other doctors know that we have a special interest in the area, they tend to send us the most complicated patients who get us really scratching our heads.  We always enjoy the challenge and go back to the books to work out the best treatment.  The fact that we work together means that our patients can get all of their injections done at the same time which is much more convenient and makes the possibility of becoming immune to the toxin much lower.