A novel diagnostic approach for patients with adult-onset dystonia

Abstract

Adult-onset dystonia can be acquired, inherited or idiopathic. The dystonia is usually focal or segmental and for a limited number of cases causal treatment is available. In recent years, rapid developments in neuroimmunology have led to increased knowledge on autoantibody-related dystonias. At the same time, genetic diagnostics in sequencing technology have evolved and revealed several new genes associated with adult-onset dystonia. Furthermore, new phenotype–genotype correlations have been elucidated. Consequently, clinicians face the dilemma of which additional investigations should be performed and whether to perform genetic testing or not. To ensure early diagnosis and to prevent unnecessary investigations, integration of new diagnostic strategies is needed.We designed a new five-step diagnostic approach for adult-onset dystonia. The first four steps are based on a broad literature search and expert opinion, the fifth step, on when to perform genetic testing, is based on a detailed systematic literature review up to 1 December 2021.The basic principle of the algorithm is that genetic testing is unlikely to lead to changes in management in three groups: (1) patients with an acquired form of adult-onset dystonia; (2) patients with neurodegenerative disorders, presenting with a combined movement disorder including dystonic symptoms and (3) patients with adult-onset isolated focal or segmental dystonia. Throughout the approach, focus lies on early identification of treatable forms of dystonia, either acquired or genetic.This novel diagnostic approach for adult-onset dystonia can help clinicians to decide when to perform additional tests, including genetic testing and facilitates early aetiological diagnosis, to enable timely treatment.

New developments in diagnostics and treatment of adult-onset focal dystonia

“…On top of that, the increasing numbers of newly discovered genes associated with adult-onset dystonia does raise the question to clinicians when further testing is justified. In a recent study, a diagnostic algorithm was designed based on extensive literature review and expert opinion to aid in the decision-making process in these cases [26 ▪▪ ] (Fig. 1).…”

“…A novel five-step diagnostic algorithm for adult-onset dystonia. ∗ For tables on specific diagnostic workup recommendations, see the original article [26 ▪▪ ]. ∗∗ The authors recommend TSH (thyroid-stimulating hormone) screening in all patients.…”

“…∗∗ The authors recommend TSH (thyroid-stimulating hormone) screening in all patients. ∗∗∗ For table on the clinical characteristics of adult-onset isolated focal dystonia (AOIFD), see the original article [26 ▪▪ ]. Source: van Egmond et al .…”

Dystonien: Diagnostische und therapeutische Herausforderungen

“…Außerdem haben viele monogene Dystonieerkrankungen eine sehr variable Penetranz. Die Infobox gibt einen Überblick über klinische Konstellationen, in denen zumindest eine hohe Wahrscheinlichkeit besteht, eine dystonieassoziierte Mutation nachzuweisen[11]. Zuvor sollte immer die übrige Diagnostik erfolgt sein.…”