Why Spasmodic dysphonia is often mistaken for a functional disorder?

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Spasmodic dysphonia, also called laryngeal dystonia, is a neurological disorder, responsible of a strangulated, strained voice and rarely of a whispering voice, which has a major negative influence at work and in personal life.

Patients with spasmodic dysphonia require to be distinguishing from patients with functional dysphonia and from patients with “muscle tension dysphonia” (MTD) which is also considered a functional disorder rather than a neurological disorder.

Many reasons can explain why spasmodic dysphonia , which is a dystonia of the larynx, is not well recognized by doctors.

1- Laryngeal dystonia is a rare condition (1/100 000), and like other focal dystonia, the diagnosis is clinical; if you have never heard somebody with spasmodic dysphonia speaking, it will be very difficult to recognize it.

2- It mainly occurs in women, who carry the stigma of being more vulnerable for functional disorders.

3- The onset can be sudden in 45% of the cases (Childs, 2011).  Sudden onset is also a characteristic of functional disorders.

4- When the onset is sudden, the majority of patients recognized triggering factors such as stress (42%), upper respiratory infection (33%), and pregnancy and parturition (10%).(Childs, 2011). Stress should be seen as a non-specific triggering factor making patients vulnerable to develop any medical conditions, and not specifically functional disorders.

5-A phobic component occurs very quickly after onset, as the patient avoid answering the phone, and speaking in public as it’s required such an effort to speak in these circumstances.

6-It’s a task specific condition as every focal dystonia,; spasmodic dysphonia occurs when speaking, and voice can be normal for singing or shouting. This task specific characteristic can be disconcerting for both the patient and the doctor.

At the difference, functional dysphonia is responsible of a permanent speech disturbance, with a whispering voice or a hoarse voice occurring when speaking, and impossibility of shouting or singing.

7- “Muscle tension dysphonia” (MDT) patients tend to exert too much effort on their vocal cords when speaking and can present with a strained voice, as spasmodic dysphonia.

But when examining the speech in details, three tasks: sustained vowel /a/, oral reading of a standard passage, and connected speech describing a standard picture have to be performed, as the spasmodic dysphonia could be more apparent in the connected speech situation, compared to MDT.

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It’s very important to diagnose spasmodic dysphonia, as Botox injections into the vocal cords can alleviate the symptoms and restore confidence for effortless speaking.

At the London BTX centre, in Sloane Square, Dr. Marie-Helene Marion offers multidisciplinary clinics with voice specialists for the diagnosis and  treatment of spasmodic dysphonia with Botox injections.

 

 

 

 

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How does my jaw move?

The functional anatomy of the jaw is essential to understand dystonic movements of the jaw when a patient is eating or speaking. The chewing movements are extremely complex and I will detail only the main posture of the jaw, following dystonic spasms.

The jaw can move in a vertical plan, with opening or closing the mouth

The jaw can move in a saggital plan, the jaw going forward ( protrusion) or backward ( retrusion)

The jaw can move in a lateral plan, the jaw going side to side or going down and to one side, called deviation of the jaw.

The masticatory muscles, responsible of these movements are 4 pairs of muscles ( masseters, temporalis, median pterygoid and lateral pterygoid muscles) and the mouth floor muscles ( supra-hyoid muscles).

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A combination of these movements is usually involved in the dystonic spams of the jaw. The video recording of a patient when chewing can be very helpful for analysing in details the dystonic spasms.

Dr MH Marion at the London BTX centre, is specialised in the treatment of dystonia, and injects under electromyogram guidance the masticatory muscles involved in oro-mandibular dystonia.

My jaw is out of control when speaking or chewing: what does it mean?

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                                                    the Iron jaw in circus

Eating is a simple pleasure of life and a necessity. Biting into a biscuit could require a tremendous effort when the movements of the jaw become out of control. The automatic movements of the jaw and the tongue, which allow us to eat or speak, can be disrupted by involuntary jaw spasms.

 

What are the causes of jaw spasms?

1-Idiopathic jaw dystonia is the most common cause of jaw spasms. The onset is between the age of 50 to 60 and it is more frequent in women. Dental works can trigger it. It’s called idiopathic dystonia as no underlying disease can be found. A genetic mutation has been identified in familial form of jaw dystonia ( DYT6).

2-Tardive jaw dystonia can follow a treatment with drugs used for the treatment of psychosis, called neuroleptics.

3- Hereditary disease affecting the brain is often the cause of jaw spasms occuring in young people, under the age of 20.

4- Hemi-masticatory spasms is usually a consequence of radiotherapy of the jaw area for cancer of the ENT sphere. In that case, the spasm is painful and affecting one side of the jaw with sudden, unexpected painful clenching of the jaw.

Are there different types of jaw dystonia?

1-The jaw spasms can be closing spasms with sudden clenching, responsible of tongue biting, teeth breaking and limitation to open the mouth wide

2-The jaw spasms can be opening spasms, responsible of difficulties to keep the mouth closed and to keep the food into the mouth. Often the tongue is involved and has a tendency to poke out the mouth.

3- The jaw spasms can also move involuntary the jaw side to side, or on one side only, or forward (protrusion) or backward (retrusion)

The movement involved in eating and speaking are incredibly complex and the dystonic spasms can be a combination of opening, deviation to one side and going backward or forward.

What are the characteristics of jaw dystonia?

The jaw spasm occurs in any attempts of eating and/or speaking, therefore the diagnosis requires looking at the patient performing these tasks. The doctors should have a box of biscuit available to examine their patients with dystonia!

The spasm are relieved by some tricks like keeping a sweet in the mouth or a chewing gum, sucking a matches or the temples of their spectacles.

How to treat jaw dystonia?

 

The most efficient treatment is the Botox injections of the masticatory muscles.

            -The muscles, which close the jaw, are the masseters, the temporalis and the median pterygoid muscles

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Masseters, closing jaw muscles

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Temporalis, closing jaw muscles

Figure adapted from Travell and Simons’  

-The muscles, which open the mouth, are the lateral pterygoid and the mouth floor muscles.

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Mouth floor muscles ( opening jaw muscles), also called supra-hyoid muscles

Figure adapted from Travell and Simons’

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Median ( closing jaw muscles) and lateral pterygoid (opening jaw muscles)

Figure adapted from Travell and Simons’

‘Some of these muscles are superficial and easy to inject ( masseters, temporalis,mouth floor muscles), some are deeper (median an lateral pterygoid muscles) and requires to be injected with electromyography guidance.

The difficult part is to analyse the abnormal movements and understand which muscles are involved in the dystonia. It can take many injections sessions, to get the spasms under control. The 2 limiting factors are the swallowing difficulties, due to the spread of the Botox , in particular when the tongue  muscles have to be injected.  Starting with small doses and increasing gradually the dosages is advisable.

The human masticatory muscles are very strong, in particular the muscles which closed the mouth; just think of the acrobats in a circus who get suspended by biting a mouthpiece. But at least injecting jaw muscles in human is possible if we compared them to the jaw clamping muscles of the crocodiles, which are extremely strong, and as hard as bone.

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 Strong closing jaw muscles of the crocodiles

Dr Marie-Helene Marion is a specialist in Botox treatment for jaw spasms, and in particular for jaw and tongue dystonia.

British Neurotoxin Network 2013 meeting, Keble college, Oxford

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 The 3rd British Neurotoxin Network annual meeting was hold in Oxford last week; 74 Botulinum toxin injectors gathered for all over UK in the superb location of Keble college. The program covered both practical and scientific aspects of botulinum toxin and dystonia.

 I gave a pre dinner talk on facial expression of emotions, looking on how the concepts have evolved from the 19th century with Charles Bells ‘s anatomical dissection of the facial muscles, to the 21st century with the influence of facial Botox injections on our expression of emotions.The collaboration of Duchenne de Boulogne with his neurophysiology study and Charles Darwin on expression of emotions in man and animals contributes to the present understanding of the universality of expressions and the recognition of basic emotions on a face, which was confirmed by Paul Ekman, an American psychologist.The Botox has been used as a research tool in the 21-st century to understand the relation between emotion and facial expression. Repressing the expression of emotions by too much cosmetic Botox or by neurological conditions such as facial palsy could disturb in return our ability to perceive emotions.

image      Duchenne de Boulogne, 1862

 imageCharles Darwin, 1872

The following morning was dedicated on reviewing the techniques and indications of the treatment of drooling by Ms Helen Witherow, maxillo-facial surgeon in London, the treatment of jaw dystonia by myself and the comparison of 2 techniques of injection: either electromyographic guided or ultra sound guided injection by Dr Sabine Klepsch , neurophysiologist in Bristol. Ms Catharina Pearce, medical student from Cardiff presented the results of a national survey on the use of Botulinum toxin in pregnant women.

In the afternoon the lectures were focusing on new concepts in dystonia and in particular the attempt of defining a new endophenotype (heritable clinical markers) for adult onset focal dystonia by Dr Sean O’riordan from Dublin and Dr Richard Grunewald from Sheffield.

 Outside the Botulinum toxin treatment, Mr Alex Green, neurosurgeon in Oxford, explored the effect of Deep Brain Surgery on dystonia and Mr Richmond Stace physiotherapist in London, the basis for retraining of cervical dystonia.

A video session, where colleagues were presenting video of dystonic patients with unexpected outcome, was animated and the opportunity again to share our individual approach to treatment.

The meeting was also a great opportunity for the secretary Mr Bells to update the UK maps of the service using botulinum toxin for treating neurological conditions. it’s accessible to anybody who is looking for a specialist centre to be treated for dystonia in particular.

 Dr Marie-Helene Marion, chair of the British Neurotoxin Network