Deep brain stimulation in the treatment of torticollis and Meige syndrome

Deep brain stimulation (DBS) is an established and accepted treatment modality of generalized dystonia. The stereotactic target to be approached with DBS leads is the internal segment of the globus pallidus (GPi). Bilateral GPi stimulation in patients suffering from primary generalized dystonia reduced dystonic movement not only in the trunk and limbs but also in the neck and face. These observations have led to the use of GPi stimulation in patients with severe torticollis and Meige syndrome refractory to pharmacological agents as well to botulinum toxin injections. An increasing number of reports indicate the effectiveness of GPi stimulation in the treatment of intractable focal and segmental dystonia. Moreover, DBS can be performed simultaneously on both sides during one operative session. This treatment modality is reversible and safer when compared to stereotactic ablative techniques. In future, DBS can become an alternative treatment for intractable focal and segmental dystonia.     

Botulinum toxin as treatment for focal dystonia: a systematic review of the pharmaco-therapeutic and pharmaco-economic value

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the pharmaco-therapeutic and pharmaco-economic value of botulinum toxin as treatment for focal dystonia, which yielded the following results. Botulinum toxin is the most effective treatment for reducing dystonic symptoms measured with dystonia-specific and general questionnaires, and pain in patients with focal dystonia. Seventy-one percent of patients with cervical dystonia had a reduction in neck pain compared to 12?% in placebo groups. Adverse events occur in 58?% of patients during treatment with botulinum toxin compared to 46?% treated with placebo. Especially dry mouth, neck weakness, dysphagia, and voice changes are common. Adverse events are usually mild and self-limiting. Health-related quality of life, measured with the SF-36 is 20?C50 points lower in patients with focal dystonia compared to controls and the effect of botulinum toxin on health-related quality of life is unclear. Botulinum toxin treatment is expensive because the drug itself is expensive. Yearly costs for treating a patient with focal dystonia with botulinum toxin range from EUR 347 to EUR 3,633 and the gain in QALYs with BTX treatment is small. Focal dystonia impairs the productivity and the ability to work. At start of botulinum toxin treatment only 47?C50?% was working. Botulinum toxin partly improves this. Overall, we conclude that botulinum toxin is an expensive drug with good effects. From a societal perspective, the costs may well weigh up to the regained quality of life. However, the available literature concerning costs, health-related quality of life and labor participation is very limited. An extensive cost-effectiveness study should be performed incorporating all these aspects.     

Orthopedic and neurological complications of cervical dystonia--review of the literature

Cervical dystonia is the most frequent form of focal dystonia. Further, cervical dystonia can occur as a feature of segmental or generalized dystonias and cerebral palsy. Treatment with botulinum toxin to relieve pain and improve functional and psychological outcome is effective, but expensive. However, pharmacoeconomic studies evaluating treatment and disease costs have not taken into consideration the long-term complications of cervical dystonia. Here we present a review of the medical literature on orthopedic and neurological complications arising from cervical dystonia, including cervical spine degeneration, spondylosis, disk herniation, vertebral subluxations and fractures, radiculopathies and myelopathies. In summary, complications are more often reported in generalized dystonia and cerebral palsy than in focal dystonia. The prevalence is not well established, published estimations go from 18 to 41% in selected populations. Awareness of the frequent occurrence of complications and screening for symptoms of radiculomyelopathy in patients with dystonia is essential to avoid irreversible spinal cord damage. Complications of cervical dystonia need to be taken into consideration when weighting risks and calculating costs of the disease and its treatment.     

Dystonia: clinical features,genetics, and treatment

PURPOSE OF REVIEW: The present review covers recent advances in dystonia research related to dystonia genetics and treatment. These have led to the discovery of novel dystonia genes and loci, to changing classification schemes, and to the introduction of improved and new treatment options. RECENT FINDINGS: Currently 13 different forms of dystonia can be distinguished on a genetic basis (dystonia types 1-13). Recently, a novel gene locus (DYT13) was detected in a family with segmental dystonia, and the gene causing myoclonus-dystonia was identified (SGCE). Furthermore, a novel mutation in the DYT1 gene is associated with a myoclonus-dystonia phenotype. Regarding dystonia treatment, patients refractory to botulinum toxin type A can now be treated with botulinum toxin type B. Selective peripheral denervation remains an effective form of treatment for patients with secondary, but probably not with primary botulinum toxin treatment failure. Finally, a renaissance of functional surgical ablative procedures has taken place, with high frequency deep brain stimulation being introduced in dystonia treatment. Bilateral pallidotomy or pallidal stimulation may provide major benefit especially in patients with generalized, disabling dystonia with the most dramatic improvements in dystonia type 1 patients. Neurostimulation may also be effective in primary segmental axial dystonia, myoclonus-dystonia, and tardive dystonia. SUMMARY: The recent mapping of additional dystonia gene loci, the identification of novel dystonia genes, and the characterization of proteins encoded by these genes have enhanced our understanding of various forms and aspects of the dystonias and have opened up new avenues for research. Treatment options include both medical and surgical therapies, with deep brain simulation being the most recent development.     

Treatment of dystonia

Dystonia may be a sign or symptom, that is comprised of complex abnormal and dynamic movements of different etiologies. A specific cause is identified in approximately 28% of patients, which only occasionally results in specific treatment. In most cases, treatment is symptomatic and designed to relieve involuntary movements, improve posture and function and reduce associated pain. Therapeutic options are dictated by clinical assessment of the topography of dystonia, severity of abnormal movements, functional impairment and progression of disease and consists of pharmacological, surgical and supportive approaches. Several advances have been made in treatment with newer medications, availability of different forms of botulinum toxin and globus pallidus deep brain stimulation (DBS). For patients with childhood-onset dystonia, the majority of whom later develop generalized dystonia, oral medication is the mainstay of therapy. Recently, DBS has emerged as an effective alternative therapy. Botulinum toxin is usually the treatment of choice for those with adult-onset primary dystonia in which dystonia usually remains focal. In patients with secondary dystonia, treatment is challenging and efficacy is typically incomplete and partially limited by side effects. Despite these treatment options, many patients with dystonia experience only partial benefit and continue to suffer significant disability. Therefore, more research is needed to better understand the underlying cause and pathophysiology of dystonia and to explore newer medications and surgical techniques for its treatment.     

Efficacy and Safety of Long-term Botulinum Toxin Treatment in Craniocervical Dystonia: A Systematic Review

Botulinum neurotoxins have been shown to be a safe and effective therapeutic option for most forms of focal dystonia, and are now considered to provide the best symptomatic treatment in these disorders. However, only a few papers addressed the long-term efficacy and safety of repeated treatments with this drug. This article reviews the data from clinical trials that have assessed the long-term results of botulinum neurotoxin type A (BoNT-A) and type B in the treatment of the different forms of focal craniocervical dystonia, cervical dystonia (CD), blepharospasm, oromandibular, and laryngeal dystonia. Studies on the long-term effects of BoNT-A therapy have demonstrated that the majority of patients comply with this repeated treatment because they experience a positive and stable effect over time. It is still unclear whether in patients with focal dystonia the mean dose of BoNT-A changes over time. In spite of the wide spectrum of side effects reported to be associated with BoNT-A treatment, there is no evidence of specific side effects due exclusively to the long-term use of such drugs. The only exception to these positive long-term findings is the occurrence of a subgroup of patients with CD who fail to maintain a sustained response after the first or second effective treatment, partly owing to the development of neutralizing antibodies against the toxin. Longitudinal studies aimed at defining the risk factors for this abnormal pattern of response to botulinum toxin treatment are currently being conducted.     

Botulinum Toxin for the Treatment of Movement Disorders

After botulinum toxin was initially used to treat strabismus in the 1970s, others started using it to treat movement disorders including blepharospasm, hemifacial spasm, cervical dystonia, spasmodic dysphonia, and oromandibular dystonia. It was discovered that botulinum toxin can be an effective treatment for focal movement disorders with limited side effects. Over the past three decades, various formulations of botulinum toxin have been developed and the therapeutic use of these toxins has expanded in movement disorders and beyond. We review the history and mechanism of action of botulinum toxin, as well as describe different formulations available and their potential therapeutic uses in movement disorders.     

Treatment of Dystonia

Selecting the appropriate treatment for dystonia begins with proper classification of disease based on age, distribution, and underlying etiology. The therapies available for dystonia include oral medications, botulinum toxin, and surgical procedures. Oral medications are generally reserved for generalized and segmental dystonia. Botulinum toxin revolutionized the treatment of focal dystonia when it was introduced for therapeutic purposes in the 1980s. Surgical procedures are available for medication-refractory dystonia, markedly affecting an individual’s quality of life.     

Evidence-based medicine in botulinum toxin therapy for cervical dystonia

Early controlled studies of botulinum toxin (BTX) in cervical dystonia were unblinded and indicated that BTX injections are more successful than medication. In this article, the use of botulinum toxin (BTX) in cervical dystonia is reviewed according to evidence-based medicine. To document the efficacy of BTX, there have been a number of prospective, placebo-controlled studies of the use of BTX in cervical dystonia. Most were double-blind, some included videotapes to provide blinded objective assessments. The more recent studies of BTX in cervical dystonia focused on particular issues such as utility of EMG guidance, comparison to anti-cholinergic treatment, BTX serotype B in BTX type A resistant and non-resistant patients and different dosages. Despite the wealth of data generated with prospective placebo-controlled studies on the effectiveness of BTX in cervical dystonia, there is uncertainty on which outcome measures to use to express the efficacy of treatments for cervical dystonia. Disease specific instruments to measure quality of life in cervical dystonia have not been used so far. Data on the use of BTX for cervical dystonia have long been restricted to small series of patients reflecting exclusively the experience of individual specialized centers.     

A practical approach to management of focal hand dystonia

Dystonia can be focal, segmental, multifocal, generalized, or hemidystonia. Focal dystonia is localized to a specific part of the body. Overall upper limb is more commonly involved in focal dystonia than lower limb and since it starts from hand, focal hand dystonia (FHD) is a more accepted terminology. Writer''s cramp and musician dystonia are commonest types of FHD. Typically this dystonia is task specific, but in some patients this specificity may be lost over a period of time. Segmental or generalized dystonia may also start as FHD, so a detailed clinical assessment is required, which should be supplemented by relevant investigations. Treatment includes oral medications, injection botulinum toxin, neurosurgery including neurostimulation, and rehabilitation. Role of injection botulinum toxin has been extensively studied in writer''s cramp patients and found to be effective; however, selection of muscles and techniques of injection are crucial in getting best results.     

Update on Treatments for Dystonia

Oral medication, botulinum toxin injections, and deep brain stimulation are the current mainstays of treatment for dystonia. In addition, physical and other supportive therapies may help prevent further complications (eg, contractures) and improve function. This review discusses evidence-based medical treatment of dystonia with an emphasis on recent advances in treatment. We will also review the current treatment approaches and suggest ways in which these therapies can be applied to individuals with dystonia.     

Adult-onset primary focal foot dystonia

Although primary focal hand dystonia has been well characterized, primary focal foot dystonia in adults has rarely been reported. Our objective was to describe the clinical phenotype and treatment outcomes in patients with primary, adult-onset focal foot dystonia. To this end we conducted a retrospective study of four consecutive patients (59.5+/-13.5 years, range 44-67) diagnosed over a period of 6 years and followed-up for at least 5 years. Focal foot dystonia resulted in variable physical impairment. Anti-dystonic agents were mildly effective whereas botulinum toxin injections provided substantial benefit when used. Focal primary focal foot dystonia seems to be a rare form of focal dystonia with distinct clinical features that may benefit from treatment with botulinum toxin.     

Evidence-based medicine in botulinum toxin therapy for cervical dystonia

Early controlled studies of botulinum toxin (BTX) in cervical dystonia were unblinded and indicated that BTX injections are more successful than medication. In this article, the use of botulinum toxin (BTX) in cervical dystonia is reviewed according to evidence-based medicine. To document the efficacy of BTX, there have been a number of prospective, placebo-controlled studies of the use of BTX in cervical dystonia. Most were double-blind, some included videotapes to provide blinded objective assessments. The more recent studies of BTX in cervical dystonia focused on particular issues such as utility of EMG guidance, comparison to anticholinergic treatment, BTX serotype B in BTX type A resistant and non-resistant patients and different dosages. Despite the wealth of data generated with prospective placebo-controlled studies on the effectiveness of BTX in cervical dystonia, there is uncertainty on which outcome measures to use to express the efficacy of treatments for cervical dystonia. Disease specific instruments to measure quality of life in cervical dystonia have not been used so far. Data on the use of BTX for cervical dystonia have long been restricted to small series of patients reflecting exclusively the experience of individual specialized centers.

     

A systematic review on the diagnosis and treatment of primary (idiopathic) dystonia and dystonia plus syndromes: report of an EFNS/MDS-ES Task Force

To review the literature on primary dystonia and dystonia plus and to provide evidence-based recommendations. Primary dystonia and dystonia plus are chronic and often disabling conditions with a widespread spectrum mainly in young people. Computerized MEDLINE and EMBASE literature reviews (1966-1967 February 2005) were conducted. The Cochrane Library was searched for relevant citations. Diagnosis and classification of dystonia are highly relevant for providing appropriate management and prognostic information, and genetic counselling. Expert observation is suggested. DYT-1 gene testing in conjunction with genetic counselling is recommended for patients with primary dystonia with onset before age 30 years and in those with an affected relative with early onset. Positive genetic testing for dystonia (e.g. DYT-1) is not sufficient to make diagnosis of dystonia. Individuals with myoclonus should be tested for the epsilon-sarcoglycan gene (DYT-11). A levodopa trial is warranted in every patient with early onset dystonia without an alternative diagnosis. Brain imaging is not routinely required when there is a confident diagnosis of primary dystonia in adult patients, whereas it is necessary in the paediatric population. Botulinum toxin (BoNT) type A (or type B if there is resistance to type A) can be regarded as first line treatment for primary cranial (excluding oromandibular) or cervical dystonia and can be effective in writing dystonia. Actual evidence is lacking on direct comparison of the clinical efficacy and safety of BoNT-A vs. BoNT-B. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for generalized or cervical dystonia, after medication or BoNT have failed to provide adequate improvement. Selective peripheral denervation is a safe procedure that is indicated exclusively in cervical dystonia. Intrathecal baclofen can be indicated in patients where secondary dystonia is combined with spasticity. The absolute and comparative efficacy and tolerability of drugs in dystonia, including anticholinergic and antidopaminergic drugs, is poorly documented and no evidence-based recommendations can be made to guide prescribing.     

Therapy of dystonia in Japan]

A questionnaire about the treatment of dystonia was sent out to 585 councilors of Societas Neurologica Japonica. One hundred and sixty-eight replies (28.7%) were collected, although some of them were excluded from the analysis because of inappropriateness. 1) The number of patients previously experienced was < 10; 37 respondents (22.7%), 10-50; 83 (50.9%), 50-100; 26 (16.0%), and > 100; 17 (10.4%). 2) Oral medication was most often the first line treatment in either of generalized dystonia, blapharospasm, cervical dystonia, and writer's cramp. Botulinum toxin injection was the first or the second line treatment in 147 (87.5%) and 116 (69.0%) respondents for blepharospasm and cervical dystonia, respectively. In these two conditions, the more experienced doctors tended to prefer botulinum toxin injection to the other treatments as the first choice (Cochran-Armitage analysis; p = 0.003 for blepharospasm and p = 0.002 for cervical dystonia). 3) Among the oral drugs, anticholinergics, especially trihexyphenidyl, were the most frequent choice in generalized dystonia, cervical dystonia, and writer's cramp. For blepharospasm, clonazepam was most favored. Sedatives, especially diazepam, were also often the drug of choice in either of these disorders. The favored drugs were not related to the respondent's experience. 4) The success rate of treatment, designated as the percentage of patients who improved through any treatment so much that the respondent was satisfied with it, was the highest in blepharospasm (65.4 +/- 24.1; mean +/- SD), followed by cervical dystonia (41.2 +/- 23.4), writer's cramp (32.9 +/- 22.5), and generalized dystonia (20.4 +/- 19.8). Only in cervical dystonia, the rate was significantly higher in more experienced respondents (regression analysis; p = 0.008). In blepharospasm (p < 0.001) and cervical dystonia (p = 0.002), regression analysis indicated that the success rate was higher in the group who preferred botulinum toxin injection to oral medication as the first line treatment. These results indicate that in Japan the treatment of choice for dystonia does not always follow the therapeutic guidelines for dystonia proposed in some foreign countries. Adopting more evidence-based rationale of treatment is encouraged, because the recent progress about the treatment of dystonia, e.g. botulinum toxin injection or the stereotaxic surgery, is reshaping dystonia from a devastating to a treatable disorder.     

Lingual protrusion dystonia: Frequency,etiology and botulinum toxin therapy

The purpose of this study was to examine lingual protrusion dystonia (LPD); its frequency, etiology and response to botulinum toxin therapy. Previous literature suggests that LPD is more frequently the result of heredodegenerative disease and that the use of botulinum toxin therapy in LPD is associated with significant adverse effects. This is a retrospective database and record review from a movement disorder clinic. Of 421 dystonia patients, we identified 17 with LPD (4%). Of these cases, the diagnoses were: primary cranial dystonia (5), primary generalized dystonia (2), tardive dystonia (7), heredodegenerative disease (1), multifactorial (1) and post-infectious (1). All primary cases had concomitant oromandibular dystonia. In some secondary cases the LPD was the only cranial feature. Nine received botulinum toxin injections and 55.6% sustained moderate or marked improvement. Of 89 total botulinum toxin sessions, 66.3% had an excellent response, and 92.1% had some response. 97.8% of the sessions resulted in no significant adverse effects. On one occasion one patient developed severe dysphagia requiring placement of a percutaneous gastrostomy (PEG) tube. We conclude that LPD is rare, most commonly the result of tardive and primary dystonia. Botulinum toxin therapy may be very effective but needs to be utilized with care because of the possibility for the development of dysphagia.     

Treatment of cervical dystonia hand spasms and laryngeal dystonia with botulinum toxin

Summary One hundred and twenty-six patients with different forms of focal dystonia (89 with cervical dystonia, 12 with hand cramps and 25 with laryngeal dystonia) were treated with localised injections of botulinum toxin. Mean doses per muscle were 200 mouse units (m.u.) for treating cervical dystonia, 40–120 m.u. for forearm muscles in writers' cramp and 3.7 m. u. for the thyroarytenoid muscle in laryngeal dystonia. Responder rates have been above 80% in all patient groups and beneficial effects could be reproduced over follow-up periods of up to 4 years. The commonest side-effects were dysphagia after treatment of spasmodic torticollis, weakness of neighbouring muscles after injections for hand cramps and breathiness and hypophonia following laryngeal injections. All these were transient and generally well tolerated. It is concluded that botulinum toxin injections are a safe and effective treatment in all three types of focal dystonia.     

Muscle selection for treatment of cervical dystonia with botulinum toxin--a systematic review

RationaleCervical dystonia, also called spasmodic torticollis, is the most common form of (primary) dystonia. Intramuscular injections with botulinum toxin are the first line of treatment for cervical dystonia. To optimise the treatment response to botulinum toxin correct muscles should be selected. Clinical evaluation is important for muscle selection but the value of additional tests to identify dystonic muscles remains unclear.ObjectiveTo evaluate all relevant literature regarding the best approach to select dystonic muscles for treatment with botulinum toxin.MethodsWe conducted a systematic review of studies that had investigated methods of selecting muscles for treatment with botulinum toxin. In addition, we compared all prospective botulinum toxin trials using either clinical evaluation or polymyographic electromyography for muscle selection.ResultsForty relevant studies were included and polymyographic electromyography recordings were most often employed. In several studies, polymyographic electromyography revealed a different pattern of muscle involvement compared to that found during clinical evaluation. In one randomized controlled trial polymyographic electromyography significantly improved the outcome of botulinum toxin treatment. A limited number of studies used positron emission tomography – computed tomography imaging or frequency analysis of the electromyography signal to identify dystonic muscles but their effect on the outcome of treatment has never been studied.ConclusionPolymyographic electromyography may improve the outcome of botulinum toxin treatment in cervical dystonia, but evidence is limited and larger studies are needed.     

The use of botulinum toxin type-B in the treatment of patients who have become unresponsive to botulinum toxin type-A -- initial experiences.

The increasing use of botulinum toxin type-A, especially for focal dystonia and spasticity has highlighted the issue of secondary non-responsiveness. Within the last few years botulinum toxin type-B (Myobloc/Neurobloc) has become commercially available as an alternative to type-A. This paper discusses our initial experience of botulinum toxin type-B in a total of 63 individuals who attended our botulinum clinic. Thirty-six patients had cervical dystonia and a secondary non-response to type-A toxin. Thirteen of these patients (36%) had a reasonable clinical response to Neurobloc and continue to have injections. The other 23 patients either had no response, or a poor response, or had unacceptable side effects and ceased treatment. A small number of people with blepharospasm, hemifacial spasm and foot dystonia also had a disappointing response to injection. Twenty patients with spasticity were also type-A resistant. Seven of these show some continuing response to type-B, without unacceptable side effects. These findings demonstrate that botulinum toxin type-B has a place in the management of patients who have become non-responsive to type-A, but overall the responses to type-B toxin were disappointing.     

An open trial of levetiracetam for segmental and generalized dystonia.

Local botulinum toxin injections represent the treatment of choice for most patients with focal dystonia. However, patients with segmental or generalized forms require additional pharmacologic treatment which is often ineffective or limited by intolerable side-effects. An animal study and three case reports suggested antidystonic effects of levetiracetam, a pyrrolidone derivate, whereas a recent open-label study found no improvement in 10 patients with primary idiopathic cervical dystonia. We studied the efficacy of levetiracetam in a daily dose of 3000 mg in 10 consecutive patients with otherwise therapy refractory segmental or generalized dystonia. At 4-week follow-up, none of the patients showed improvement of dystonia, mild side-effects were observed in 3 patients.