Medical and Surgical Treatments for Dystonia

Abstract

The dystonias are a large and heterogenous group of disorders characterized by excessive muscle contractions leading to abnormal postures and/or repetitive movements. Their clinical manifestations vary widely, and there are many potential causes. Despite the heterogeneity, helpful treatments are available for the vast majority of patients. Symptom-based therapies include oral medications, botulinum toxins, and surgical interventions. For some subtypes of dystonia, specific mechanism-based treatments are available. Advances in understanding the biological basis for many types of dystonia have led to numerous recent clinical trials, so additional treatments are likely to become available in the very near future.

Keywords: Blepharospasm; Botulinum toxin; Deep brain stimulation; Meige syndrome; Oromandibular dystonia; Therapy; Torticollis.

Figure 1.. Classification of the dystonias.

The many types of dystonia are classified according to two axes. The first axis relates to clinical features. The main factors important for clinical classification include age at onset, body distribution, temporal features, and whether or not dystonia is combined with other neurological or medical problems. The main factors important for etiological classification include whether the disorder is associated with relevant brain pathology, and whether the disorder is acquired or inherited. However, a large proportion of cases remain idiopathic.

Figure 2.. Diagnostic approach.

This algorithm provides a basic strategy for the diagnostic approach to most patients with dystonia. The initial step is to determine whether the disorder being considered is a type of dystonia, or something that may mimic dystonia. The next step is to use the history and examination to delineate the dystonia syndrome, using the main clinical features used for classification. The third step is to consider potential etiologies.

Figure 3.. Treatment approach.

This algorithm provides a basic strategy for the therapeutic approach to most patients with dystonia. The clinical and etiological evaluations are important, because They influence optimal treatments strategies. For children, diagnostic testing is essential because there is a greater likelihood of discovering a treatable cause. When a cause cannot be found, a trial of oral levodopa is conducted to rule out dopa-responsive dystonia. For adults, dystonia is more often idiopathic, so extensive workup is often not needed. Instead, the approach depends on body distribution. For the focal dystonias, botulinum toxins provide a useful starting point. Oral medications can be used, but often are not well-tolerated. Those who have unsatisfactory responses can be offered surgery. Generalized dystonias or dystonia combined with other neurological problems in adults requires some additional diagnostic testing, to disclose a potentially treatable cause.