general definition of dystonia and propose a new classi- fication. We encourage classification and etiology of dystonia syndromes The first. @dystonie dystonie/NSSavePanel.m. Created 6 years alloc] init] autorelease];. [savePanel setAllowedFileTypes:[NSArray arrayWithObjects:@”fileType”, nil]];. @dystonie dystonie/NSOpenPanel.m. Created 6 years ago. Embed [ openPanel setAllowsMultipleSelection:NO];. [openPanel setAllowedFileTypes: filetypes];.
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There are many different clinical manifestations and many different causes. A careful assessment of the clinical manifestations is helpful for identifying syndromic patterns that focus diagnostic testing on potential causes. If a cause can be identified, specific etiology-based treatments may be available. However, in the majority of cases, a specific cause cannot be identified, and treatments are based on symptoms. Treatment options include counseling and education, oral medications, botulinum toxin injections, and several surgical procedures.
A substantial reduction in symptoms and improved quality of life can be achieved in the majority of patients by combining these various options. The dystonias are a group of disorders defined by specific types of abnormal movements. The essential feature is over-activity of muscles needed for movement. This over-activity can be expressed as excessive force in the primary muscles used for a movement, overflow activation of additional muscles that are not required for a movement, or co-activation of muscles that antagonize the primary muscles.
The clinical expression of dystonia is determined by the severity and distribution of muscles involved. In mild cases dystonic movements appear merely as exaggerations of specific actions. In moderate cases the movements are more clearly abnormal with a quality that is cramped, stiff or twisting. In more severe cases dystonic movements appear as persistent odd postures or fixed deformities.
Dystonic movements are often slow, but they sometimes may be rapid or jerky.
A recent consensus work group provided the following formal definition for the dystonias: Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive movements, postures, or both. Dystonic movements are typically patterned, twisting, and may be tremulous. Dystonia is often initiated or worsened by voluntary action and associated with overflow muscle activation.
Virtually any region of the body may be affected, alone or in various combinations. The dystonias may emerge at any age; and once they begin, they rarely remit. Some remain relatively static, while others are progressive or intermittent. Dystonia may occur in isolation, or it may be combined with other clinical problems.
The many different clinical manifestations are classified according to four dimensions Table 1 including the region of the body affected, the age at onset, temporal aspects, and whether there are associated clinical problems. In addition to the widely varying clinical manifestations of the dystonias, there also are many different causes.
Some dystonias have no apparent pathology in the nervous system, while others are associated with defects that can be detected by neuroimaging or post-mortem histopathological studies.
At the molecular level, multiple genes have dsytonie discovered for rare subtypes of dystonia, 89 and they are involved in diverse biochemical processes. Because there are so many different clinical manifestations and causes, there are no simple algorithms for diagnosis that address all dystonias.
Diagnosis & Treatment of Dystonia
This strategy also is untenable, because recent progress in dystonia research has led to a long list of treatable disorders that grows every year Table 3. A more methodical strategy for diagnosis is shown in Figure 1. Once a diagnosis of dystonia is suspected based on clinical phenomenology, the first step is to rule out disorders that may mimic dystonia pseudodystoniasuch as those due to orthopedic, neuromuscular or psychogenic processes.
The next step is to delineate the clinical syndrome according to the four dimensions used for clinical classification Table 1. A careful delineation of the syndromic pattern, along with neuroimaging characteristics, is important because it aids in narrowing down the long list of potential etiologies for more targeted diagnostic testing.
For patients with isolated dystonia, the laboratory workup depends on the age at onset, the body distribution, and whether there are affected family members.
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In adults with focal or segmental dystonia ciletype, no diagnostic tests are required because they usually are unrevealing. The diagnostic approach in younger dsytonie with isolated dystonia is quite different, filtype there dysttonie a much higher likelihood of disclosing a cause. For all patients where dystonia is combined with other neurological or systemic features, some additional workup is warranted, regardless of the age at onset or body distribution.
The laboratory filwtype depends on the nature of the associated features and the age at onset. A recent review summarized more than different disorders where dystonia may be combined with other features, organized in 18 tables according to the associated clinical features and age at onset.
Instead, laboratory testing is driven by the syndromic pattern. For example, dystonia combined with Parkinsonism leads to a relatively small list of filetyppe for more targeted diagnostic testing. When a specific etiology cannot be determined, it is important to follow patients and revise the diagnosis as additional clinical features are recognized. Many combined dystonic disorders may present first with what appears to be isolated dystonia, and additional clinical features may develop over the following months or years.
There are many different treatment options that involve counseling and education, oral medications, intramuscular injection of botulinum neurotoxins BoNTphysical and occupational therapy, and dysgonie interventions. In the next section these options are summarized individually. Subsequently, some suggestions are offered for how these individual ingredients can be combined for the best outcomes in different types of dystonia. Education and counseling are important for several reasons.
Patients frequently are misdiagnosed for many years, and many are told they suffering from a psychiatric problem. Even for the most common and readily diagnosed subtypes of dystonia such as cervical dystonia, the mean time from onset of symptoms to diagnosis is 4—6 years. Education and counseling are important for regaining trust so that patients are more likely to accept dysttonie. Education and counseling also flietype important because few therapies are curative.
Achieving the best outcome often requires an empirical trial and error approach, which can sometimes amplify existing frustration and mistrust. A frank discussion of treatment options is essential to ensure that expectations are realistic. It is also worth bearing in mind that there is a high rate of psychiatric co-morbidity in the dystonias including depression, anxiety and social withdrawal.
Finally, many patients learn about their medical diagnoses and treatment options via the internet, which is not always a reliable source of information. Educating patients about the most reliable online sources of information dystohie help to avoid misunderstandings.
Table 4 provides a summary of some internet sites where information is regularly updated, and other educational and research opportunities are available to patients. Most of these groups also provide informational brochures, newsletters and local patient support group meetings where patients can obtain new information. Patients frequently ask about the value of exercise and physical therapy, because they seem intuitively helpful for addressing abnormal filetyype activity and pain.
Although many patients seem to appreciate physical therapy, benefits often are temporary, and there are no large-scale double-blind studies that demonstrate objective benefits to justify regular application. Several investigators have sought to demonstrate objective improvements using specific methods based on theories regarding the pathophysiology of dystonia.
Despite the enthusiasm for physical therapy in dystonia, systematic reviews have concluded that there is insufficient evidence to recommend any particular strategy.
First, most of the studies have been quite small with outcomes that often were not reproducible, and the larger studies frequently demonstrated wide response variations among patients. Second, the reported benefits often have been filletype small, transient, or subjective.
Third, there is a tradition in physical therapy to customize procedures according to the needs of individual patients. As a result, large studies using uniform protocols are scarce. Double-blind and placebo-controlled studies are rare also in part because of the difficulty in designing an appropriate control group ciletype rule out non-specific placebo effects. Finally, many of the methods are cumbersome and filetypd consuming, limiting enthusiasm for clinical application.
Enthusiasm for specific strategies also is blunted by concerns that some well-intentioned designs may be harmful. For example, significant improvements have been reported for patients with hand dystonia following 4—6 weeks of immobilization with a rigid splint.
In the absence of solid evidence to guide more specific recommendations, it seems reasonable to incorporate general physical therapy methods according to patient preferences. These may include regular dystnie exercises to mitigate against contractures, muscle relaxation filetupe to attenuate pulling and pain, and strengthening of antagonist muscles to balance abnormal postures. Dystomie assistive devices also are available to allow more significantly disabled patients to function more independently.
There are multiple articles summarizing oral medications for dystonia, 59 — 63 including two systematic evidence-based reviews. None of them has been FDA approved for treatment of dystonia. Much of the evidence supporting the use of these drugs comes from small controlled trials, non-blinded trials, retrospective reviews, and anecdotal experience Table 5.
One of the most frequently prescribed classes of medications for the dystonias include anticholinergics dysyonie as trihexyphenidyl, riletype, biperidin, ethopropazine, orphenadrine, and procyclidine. These drugs are fiketype to work by blocking muscarinic acetylcholine filetjpe in the basal ganglia. Similar studies of children with dystonia associated with cerebral palsy showed that a significant proportion may worsen with anticholinergics.
Despite the limited and sometimes conflicting information, anticholinergics remain in broad use because they seem to be at least partly effective for many types of dystonia, regardless of the underlying etiology. Trihexyphenidyl must be started at a low dose, for example 2 mg twice daily. It can be increased by 2 mg every few days until benefits are observed or side effects emerge.
Effective doses range from 6—40 mg daily, divided across 3—4 doses. Typical side effects include memory loss, confusion, restlessness, depression, dry mouth, constipation, urinary retention, blurry vision or worsening of narrow-angle glaucoma. Medications dystonei augment or suppress dopaminergic transmission in the basal ganglia may be extraordinarily helpful in select populations of patients with dystonia. Augmenting dopamine transmission with levodopa is dramatically effective in dopa-responsive dystonia, which is most often caused by mutations in the GCH1 gene encoding the enzyme GTP-cyclohydrolase.
In addition to levodopa, patients with classical dopa-responsive dystonia respond to dopamine agonists and drugs that block dopamine metabolism such dtstonie monoamine oxidase inhibitors. Levodopa is also at least partially effective in other disorders affecting dopamine synthesis that are caused by deficiency of tyrosine hydroxylase, sepiapterin reductase, and others. Aside from these specific populations, levodopa and dopamine agonists are not broadly useful for other types of dystonia, such as the more common adult-onset isolated focal or segmental dystonias.
Medications that suppress dopaminergic transmission also may be useful for specific subgroups of patients. Although dopamine receptor antagonists have been used with variable success in small un-blinded studies, their use is generally discouraged because the risk for development of acute dystonic reactions and tardive syndromes may lead to diagnostic confusion. However, depletion of dopamine with tetrabenazine does not carry these same risks, and it may be useful for some patients with dystonia, particularly those with tardive dystonia.
Dose-limiting side effects include drowsiness, parkinsonism, depression, insomnia, filrtype, anxiety, and akathisia. Another frequently prescribed group of medications is the benzodiazepines such as alprazolam, chlordiazepoxide, clonazepam, and diazepam.
They are thought to work by amplifying transmission through GABA receptors. There are no large double-blind and controlled studies of the benzodiazepines in dystonia.
Their use is supported by multiple dystoine or retrospective studies. Anecdotal experience suggests they may be most useful for suppressing phasic aspects of dystonia, such filetyle blinking in blepharospasm or tremor-dominant forms of dystonia. There also is a risk for tachyphylaxis and dependency, so abrupt discontinuation or sudden large decreases in doses should be avoided.
Baclofen is a GABA receptor agonist that also is often used in dystonia.