Treatment
Focal dystonias
The aim of treatment is to reduce symptoms of muscle spasm and awkward postures caused by dystonia to enable as normal a life as possible.
Treatments used for the different types of dystonia are similar. The treatments are described and notes on each type of dystonia are also provided with brief notes on what type of treatment is most likely to be used and the general effectiveness of such treatments.
Drug treatments
Botulinum Toxin Injections
This is the main treatment used for focal dystonia. Botulinum toxin is a toxin produced by the bacterium Clostridium botulinum. It is infection with this toxin producing organism which causes the potentially fatal paralytic disease botulism. The toxin blocks nerve function at the neuromuscular junction. Injecting tiny amounts of the toxin into abnormally contracting muscles or those in spasm partially paralyses them and relieves symptoms of dystonia. The toxin takes up to a week to achieve maximum paralysing effect; the nerves recover and start working again over the following 8-9 weeks. Botulinum toxin injections are usually repeated every 12 weeks to maintain the treatment effect and keep dystonia under control. Over the 12 week treatment period dystonia symptoms will recur and may be very troublesome again by the time of the next treatment. The effect of botulinum toxin is therefore to control the dystonia for most of the time with possible troublesome symptoms in-between appointments. If appointments are delayed to 16 week intervals there will be a longer symptomatic period with disabling effects.
There are two main types of botulinum toxin:
- Botulinum toxin type A – trade names: Botox, Dysport, Xeomin
- Botulinum toxin type B - trade names: Myobloc, Neurobloc
Botulinum toxin type F is a new type that may become more widely used, but its shorter duration of action means that its use is likely to be limited.
Problems with botulinum toxin include:
- Problems targeting the injections to gain maximum treatment effect – dystonia symptoms may not be much improved. EMG tests may be used to target injections at most affected muscles.
- Paralysis of other muscles – dystonia adequately treated but problems with weakness of other muscles interfering with life – head droop or difficulty swallowing after torticollis treatment for example. Weakness is always temporary.
- Immunity to botulinum toxin – in some people over time the treatment stops working; this is because the immune system makes antibodies against the botulinum toxin. It can either be primary resistance, meaning the injections never work, or come on after time (secondary resistance). With time the injections of botulinum toxin will have no effect on muscle contraction or dystonia. The botulinum toxin can be substituted for another type but antibodies may also be produced against the new type. This will leave only the less effective drug treatments and non-drug therapies available. These cases are rare but as dystonia cannot be effectively controlled it may be disabling.
For the majority of people repeated botulinum toxin injections can be used to control dystonia for many years.
Tablet treatments
None of the drug treatments available for dystonia are completely effective and many have quite severe side effects. Often treatment will be a balance between reducing muscle spasm or tremor and tolerance of side effects. For most of the focal dystonias the best treatment will be regular botulinum toxin injections if these are effective and are tolerated.
The following drugs and their side effects include:
- Anticholinergics including trihexylphenidyl (benzhexol), benztropine and ethopropazine. These affect a neurotransmitter within the brain to reduce abnormalities in the motor pathways and hence dystonia. They appear to be more effective in childhood onset more severe dystonia. Anticholinergic side effects very often limit their use. These side effects include: dry mouth, blurred vision, urinary retention and constipation. Central side effects include confusion, drowsiness, hallucination, personality change, and memory problems.
- Benzodiazepines including diazepam, clonazepam and lorazepam can effectively reduce muscle spasm. Their main side effect is sedation and they are highly addictive. Other side effects include depression and personality change.
- Baclofen is a muscle relaxant which can be given in tablet form or with an implanted pump that injects Baclofen into the intrathecal space around the spinal nerve roots. Side effects may include confusion, dizziness, drowsiness, nausea, and muscle weakness.
- Antiepileptic drugs such as carbamazepine (tegretol) are effective treatment for some forms of dystonia (mainly paroxysmal dystonia). Potential side effects include dizziness, drowsiness, rashes and liver damage.
- Dopaminergic drugs, these drugs increase levels of the neurotransmitter dopamine and are also used to treat Parkinson’s disease. Names of drugs include levodopa (Sinemet, madopar) and dopamine agonists such as ropinirole, pramipexole and cabergoline. Side effects include sedation, nausea, low blood pressure and depression. A useful treatment response is only usually seen in those individuals with the rare condition dopa-responsive dystonia.
- Dopamine depleting drugs: Other drugs which reduce levels of dopamine are effective in a minority of people; such drugs include clozapine (Clozaril). Clozapine is an antipsychotic with rare but serious side effects – including heart failure, liver damage and immunosuppression. Regular blood test monitoring is required. Other drugs include tetrabenazine which may cause depression or drowsiness. Tetrabenzine is one of the more effective drug treatments for the movement disorder tardive dyskinesia and Huntingdon’s Chorea. These drugs are rarely used in treating dystonias.
Non-drug treatments
Surgery
Surgery for dystonia may involve an operation to destroy the nerve to the overactive muscles responsible for the dystonic movements to prevent the abnormal contractions, or brain surgery to reduce the abnormal movements centrally. Surgical treatment is very much used as a last resort, when all other treatments have failed and quality of life is unacceptable because of continuing dystonia. Recovery from local surgery or brain surgery would be expected to take only a few weeks. If surgery improves the condition, such improvement is fairly immediate and sustained. The exception to this is ‘Deep Brain Stimulation’ (DBS) during this procedure small permanent electrodes are inserted into the brain which produce a current that can modify brain electrical activity and improve movement disorders. The generator for this voltage is usually implanted under the skin of the chest wall for easy access. The current applied will need to be calibrated over time to gain best effect on the dystonia. This may take up to 6 months; the level of improvement is maintained over time once the correct level is set. Further operations over the years are necessary for maintenance or replacement of the stimulator unit under the chest wall. Waiting times for initial procedure may be significant.
Physiotherapy
Dystonia is a movement disorder and in addition to painful abnormal movements or postures from dystonia, unaffected parts of the body may compensate to overcome abnormal movements or posture. A good example of this is torticollis. If the neck is twisted into an abnormal posture, it is natural for the back to twist to compensate for this to retain a normal visual field. Compensatory twisting to overcome dystonia may cause pain and discomfort in addition to pain from dystonia. A physiotherapist preferably a neuro-physiotherapist can increase awareness of movement and posture and teach alternative coping mechanisms that reduce pain and discomfort from compensatory posturing. This type of treatment is usually given in addition to any drug treatment for dystonia treatment and will have no effect on the dystonia itself but may increase quality of life. Although this may be dependent on whether there is any skeletal damage or Spondylosis.
Speech Therapy
If the voice or swallowing is affected by dystonia, speech therapy may help. A speech therapist can teach techniques that enable a person to optimize their ability to speak and swallow. This is likely to be in addition to any drug treatment.
Overview of treatment of individual focal dystonias
Blepharospasm
Botulinum toxin is the most effective treatment for blepharospasm, markedly improving symptoms in 95%. Injections need to be repeated regularly every 10-12 weeks to maintain the treatment effect and there may be annoying or disabling return of symptoms prior to each treatment. Complications of treatment include ptosis, dry eyes and difficulty completely closing the eyes causing dryness, bruising and lower facial weakness. Dose and injection site can be modified over time to improve clinical effect and reduce complications. For those in whom botulinum toxin is ineffective surgery is an option, this involves removing some of the muscle around the eye involved in abnormal blinking; the procedure is called ‘myectomy’. Drugs are not that useful, many people will not respond to drugs and those who do have only a partial response. Benzodiazepines can be helpful but their use is usually limited by side-effects.
Oromandibular dystonia
Botulinum toxin is the most effective treatment for Oromandibular dystonia, but success rates are much lower than for blepharospasm and are dependent on how many, and which, muscles are overactive. In many individuals, there is only a little or no improvement. Injections need to be repeated regularly to maintain the treatment effect and there may be annoying or disabling return of symptoms prior to each treatment. Complications of treatment include temporary difficulty swallowing, pain and bruising at the injection site. The muscles affected can be difficult identify and inject, an EMG may be used to target treatment.
Drugs are not that useful, many people will not respond to drugs and those who do have only a partial response. Benzodiazepines and Anticholinergics are most commonly used – see drugs and their side effects.
Spasmodic dysphonia or laryngeal dystonia
Botulinum toxin is most often used to treat this condition. Targeting the injections into the correct small muscles around the voice box can be difficult and this is usually performed by an ENT surgeon with EMG monitoring. Other treatments that may be used include any of the drug treatments and speech therapy.
Spasmodic torticollis or cervical dystonia
Botulinum toxin is the main treatment used for cervical dystonia and is very effective for some people. Other treatments that may be used in addition to this are physiotherapy especially to help with secondary musculoskeletal pain from altered posture. Sensory feedback training and muscle relaxation techniques may be tried. Certain activities may make symptoms much worse; physiotherapy assessment can help to identify these.
If these treatments don’t improve symptoms then drugs may be used particularly clonazepam and baclofen - these are likely to reduce but not completely control symptoms. Other drugs described in the treatment section may also be used.
Surgery
This is a last resort for people who do not respond to botulinum toxin injections. Operations include surgery to nerves supplying the neck muscles, this is called ‘selective peripheral denervation’, this operation can be effective in 60-80% of people although symptoms can recur after surgery. In those employed return to work rates after surgery are around 80%.
A more invasive operation called ‘ramisectomy’ was commonly performed in the past, this involved destroying the nerve roots supplying the neck muscles and is more disfiguring and invasive than selective peripheral denervation. Long term results of this surgery showed only a third derived benefit and this was unlikely to improve function enough for them to gain employment. This operation has been superseded by selective peripheral denervation.
Deep Brain Stimulation
This has been used in this condition and does improve symptoms markedly; disability scores related to abnormal movement may improve by as much as 75%. However only a small proportion will improve enough to gain employment.
Hemifacial spasm
The main treatment used is botulinum toxin injection which can be very effective for most people (>80%). Problems with this treatment include excessive weakness of the treated muscles which usually resolves in a few weeks. Particular problems include inability to close the eye which may become dry or drooping of the eyelid – this is called ptosis. Drugs may be used but are not very effective. Younger people and those in whom botulinum toxin is not working may undergo surgery to relieve the problem. The operation is called Microvascular Decompression ‘MVD’. This procedure involves neurosurgery on the facial nerve as it exits the skull and clearing away any blood vessels impinging in the nerve. This operation has a risk of serious side effects which includes complete or partial paralysis of one side of the face and complete nerve deafness on the affected side. Around 10% of patients will have one of these serious complications including complete deafness on one side. Another 10% will temporarily have paralysis of one side of the face or deafness for some time after surgery – recovery usually occurs slowly over many months. The procedure stops twitching in almost every case. Around 70% will be cured of their condition and very satisfied with the results of such surgery.
Writer’s cramp or focal hand dystonia
Botulinum toxin can improve the condition but is not as effective as it is in the cervical dystonias. The main side effect is weakness of the forearm muscles. Drugs may be helpful if tremor is a significant problem in addition to abnormal spasms. Retraining and physiotherapy can be tried but the best course of action is to avoid the activity that precipitates the dystonia e.g. avoid writing and use a typing aid for example. This may be very difficult and may involve an unwanted change in employment. The same is true for other focal task specific dystonias.
Generalised dystonias
Idiopathic Torsion dystonia
This type of dystonia affects the whole body so drug treatment is most often used.
Typical drugs used include:
- Benzodiazepines such as diazepam in large doses.
- Benzhexol –up to 120mg per day.
These drugs will have some effect in up to 50% of affected children and up to 19% of adults. Other drugs that may be used include any of the drugs listed under drug treatment options for focal dystonia. As with focal dystonia, treatment is likely to only partially reduce movements and may improve comfort but not disabling effects. Generalised dystonia is likely to severely impair walking in most cases despite drug treatment.
Surgery
Surgical treatment is very much used as a last resort when all other treatments have failed and quality of life is unacceptable because of continuing dystonia. Most commonly brain surgery will be used for generalised dystonia, particularly ‘Deep Brain Stimulation’ or ‘DBS’. During this procedure small permanent electrodes are inserted into the brain, these produce a current that can modify brain electrical activity and improve movement disorders. The generator for this current is usually implanted under the skin of the chest wall for easy access. The current applied will need to be calibrated over time to gain best effect on the dystonia. This may take up to 6 months; the level of improvement is maintained over time once the correct level is set. Further operations over the years are necessary for maintenance of the unit under the skin of chest wall. It is likely to take up to two years to gain maximal effect from the surgery, this is because in addition to calibrating the stimulation current, a period of learning and adapting to new circumstances is required. The ability to walk independently for reasonable distances and to carry out all aspects of self care may be achieved.
Dopa-responsive dystonia-parkinsonism (DRD/Segawa’s Syndrome)
This condition responds well to low doses of levodopa. When levodopa is used to treat this condition it does not have the side effects it has when used to treat Parkinson’s disease and the dose and dose frequency can be kept the same for many years with stable treatment effect. The condition responds very well to levodopa, treatment may enable resumption of walking ability and self –care.
Rare dystonias
Myoclonus dystonia
The condition can respond to benzodiazepines (such as clonazepam), but treatment effect is limited by tolerance and addiction. In recent years, a small number of cases have been shown to benefit from Deep Brain Stimulation.
Tardive dystonia
The most effective treatment is to stop the causative drug as soon as possible. Symptoms will often disappear if this is done quickly enough. If this is not possible symptoms can be improved by the use of other drug treatments including clozapine, anti-cholinergic drugs and baclofen. Botulinum toxin treatment can be used to reduce specific movements. Deep Brain Stimulation (DBS) surgery has been used very effectively in a small number of cases but this is not widespread or common practice in 2008.
Tardive dyskinesia
The most effective treatment is to stop the causative drug as soon as possible. Symptoms will often disappear if this is done quickly enough. If this is not possible symptoms can be improved by the use of other drug treatments including clozapine, anti-cholinergic drugs and baclofen. Botulinum toxin treatment can be used to reduce specific movements. Deep Brain Stimulation (DBS) surgery has been used very effectively in a small number of cases but this is not widespread or common practice in 2008.
Amended May 2009
