Complex dystonias: an update on diagnosis and care

Abstract

Complex dystonias are defined as dystonias that are accompanied by neurologic or systemic manifestations beyond movement disorders. Many syndromes or diseases can present with complex dystonia, either as the cardinal sign or as part of a multi-systemic manifestation. Complex dystonia often gradually develops in the disease course, but can also be present from the outset. If available, the diagnostic workup, disease-specific treatment, and management of patients with complex dystonias require a multi-disciplinary approach. This article summarizes current knowledge on complex dystonias with a particular view of recent developments with respect to advances in diagnosis and management, including causative treatments.

Classification of Dystonia

“…The subdivision into isolated or combined dystonias appeared insufficient to include all the conditions that present dystonia among the clinical manifestations; therefore, a new category has been proposed, that of complex dystonia [32], in which dystonia is accompanied by other neurological (non-movement disorders) or systemic manifestations. A classic example is Wilson disease, characterized by dystonia and other neurological, psychiatric, and liver manifestations [1,33].…”

“…This category encompasses conditions in which dystonia dominates the clinical picture in the context of a complex phenotype including symptoms other than movement disorder. Subsequent studies further characterized this new category of dystonia and defined main clinical and genetic syndromes, which fall in this category [32]. The debate around this new category was further enriched using whole exome sequencing in patients with early-onset and familial dystonia, which identified a potential overlap between neurodevelopmental disorder and dystonia [34][35][36].…”

The importance of genetic testing for dystonia patients and translational research

“…Hence, in preselected patients with a likely genetic etiology of dystonia, the probability of establishing a genetic diagnosis correlates with the number of investigated genes. Frequently, dystonia is a part of a complex neurological and sometimes multisystemic disease presentation (Herzog et al 2020). In such cases, phenotypic clues are too diverse and unspecific, and a wide-reaching type of genetic testing is instrumental and crucial for arriving at a proper clinical diagnosis.…”

Dystonia updates: definition, nomenclature, clinical classification, and etiology

“…For this reason and further extending beyond a dichotomous scheme of isolated vs. combined dystonia, we would like to suggest the use of three terms, i.e. isolated, combined, and complex dystonia, each of which will be featured in accompanying reviews of this issue (Domingo et al 2020;Herzog et al 2020). Isolated dystonia describes phenotypes, where dystonia is the sole motor feature, with the exception of tremor.…”