This page contains information about laryngeal dystonia (voice dystonia) for medical professionals. For information on laryngeal dystonia for patients and carers please click here.
Laryngeal dystonia is a rare neurological voice disorder caused by involuntary muscle contractions in the vocal cords. It can also be termed spasmodic dysphonia. It is believed to be the result of incorrect messages from the brain to the muscles in the throat. It is usually diagnosed and treated by a laryngologist or an ear, nose and throat (ENT) surgeon.
Laryngeal dystonia is classified as a focal dystonia which means it affects only one region of the body. However, in some cases, laryngeal dystonia is part of a dystonia affecting two or more regions of the body and this is classified as a multifocal, segmental or generalised dystonia depending on the body regions affected.
In the majority of cases, laryngeal dystonia is a primary pure dystonia. This means that torsion dystonia is the only clinical sign (apart from tremor) and there is no identifiable exogenous cause or other inherited or degenerative disease.
Laryngeal dystonia usually appears usually appear in mid-life but sometimes affect younger or older people. It is therefore classified as a late-onset dystonia.
Laryngeal dystonia causes a strained voice sometimes with a tremor. It becomes an effort to speak. There are two main types of laryngeal dystonia and they have different symptoms:
In some cases, patients may exhibit both types of laryngeal dystonia at the same time.
Laryngeal dystonia is often misdiagnosed by GPs. Conditions that laryngeal dystonia is mistaken for include throat cancer, acid reflux, nerve damage and a psychological problem. It is still a very under-recognised condition, with patients still reporting that it can take three or four years or more before a diagnosis is made by referral to a neurologist.
Indicators for a GP that the diagnosis may be laryngeal dystonia rather one of these other conditions include:
Treatment of laryngeal dystonia can be difficult, and results of treatment vary greatly between different people. The principal treatment involves the injection of botulinum toxin to weaken the muscles affected by spasm. Injections have to be repeated every three months or so. Injections into the vocal cords are technically quite difficult, and a very precise dose needs to be given to avoid weakening the muscle too much.
Any excessive weakness of the injected muscles is usually temporary. Because of these difficulties, muscles are usually injected using electromyography (EMG) – a tool that helps identify which muscles are affected most by the dystonia, and is only usually performed by ear, nose and throat (ENT) doctors with special training. In other people tablet treatment can be tried, although the results can be quite variable from person to person and side effects can occur.
Speech/voice therapy can help minimize spasms and the effects of the spasms. Fatigue is often a significant component of laryngeal dystonia because it may take a great effort to speak. Voice therapy techniques that focus on controlling the breath and using the breath to make the most of the voice may be helpful.
Last reviewed March 2012
The Dystonia Society provides the information on this page as general information only. It is not intended to provide instruction and you should not rely on this information to determine diagnosis, prognosis or a course of treatment. It should not be used in place of a professional consultation with a doctor.
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