The focal dystonias: Current views and challenges for future research

Abstract

The most common forms of dystonia are those that develop in adults and affect a relatively isolated region of the body. Although these adult-onset focal dystonias are most prevalent, knowledge of their etiologies and pathogenesis has lagged behind some of the rarer generalized dystonias, where the identification of genetic defects has facilitated both basic and clinical research. This summary provides a brief review of the clinical manifestations of the adult-onset focal dystonias, focussing attention on less well-understood clinical manifestations that need further study. It also provides a simple conceptual model for the similarities and differences among the different adult-onset focal dystonias, as a rationale for lumping them together as a class of disorders while at the same time splitting them into subtypes. The concluding section outlines some of the most important research questions for the future. Answers to these questions are critical for advancing our understanding of this group of disorders, and for developing novel therapeutics.

Diagnosis and Treatment of Dystonia

“…In adults with focal or segmental dystonia only, no diagnostic tests are required because they usually are unrevealing. 18,21 In adults with hemidystonia or generalized dystonia, neuroimaging is useful because the likelihood of disclosing a structural cause is higher. In sporadic adult-onset isolated dystonias, the chance of finding a genetic cause is less than 1–2%, so genetic testing usually is not cost effective, unless there are other affected family members.…”

“…15–17 Determining how these diverse processes relate to one another to produce the motor syndrome we know as dystonia is a major current focus of research. 11,18 …”

Designing Clinical Trials for Dystonia

“…It has been suggested that several forms of dystonia may have shared etiologies [13][14][15] and therefore may respond to the same therapeutic intervention. Although the primary cause for the signs and symptoms of dystonia may differ, there are several reasons to suspect a common underlying process [6].…”

An unusual cause of focal hand dystonia due to a retained implant of the distal radius

“…Spontaneous remissions occur only in a few cases. The treatment usually followed traditionally includes anticholinergic drugs, benzodiazepines, botulinum toxin injection, brain surgery, limb immobilisation, behavioural therapy, biofeedback, hypnotherapy and relaxation therapy 11. However, there is no evidence of long-term efficacy of any of these modalities.…”