Remission in dystonia – Systematic review of the literature and meta-analysis

Abstract

In isolated, sporadic dystonia, it has been occasionally reported that some patients might undergo symptom remission. However, the exact clinical characteristics of patients with remission remain understudied. Given the important prognostic and pathophysiological implications of dystonic remission, we here provide a systematic review of the literature and a meta-analysis to assess demographic and clinical features associated with this phenomenon. We also provide a list of operational criteria to better define dystonic remission. Using PubMed and Embase, we conducted a systematic literature search in March 2018. 626 records were screened, 31 studies comprising data of 2551 patients with predominantly reports from patients with cervical dystonia (n=1319) or blepharospasm/Meige syndrome (n=704) were included in qualitative analysis. Five studies reporting remission in cervical dystonia were eligible for meta-analysis. Complete remission was reported in 11.8% and partial remission for 4.4% of cases. Remission rates were higher in cervical dystonia than in blepharospasm/Meige (e.g. complete remission 15.4% vs. 5.8% respectively). Remission occurred on average 4.5 years after onset of dystonic symptoms. However, the majority of patients (63.8%) relapsed. Meta-analysis for cervical dystonia showed that patients with remission were significantly younger at symptom onset than patients without remission (mean difference -7.13 years 95% CI: -10.58 − -3.68, p<0.0001). Based on our findings, we propose that the degree, the conditions associated with the onset and the duration of remission are key factors to be considered in a unifying definition of dystonic remission.

Olfaction as a Marker for Dystonia: Background, Current State and Directions

“…A state marker may be used to assess the response to a treatment or to predict the course of a disease. About 15% of the subjects with cervical dystonia and about 6% of the subjects with blepharospasm have a remission of dystonia [ 185 ]. Unfortunately, most of these subjects relapse within 4 to 5 years [ 185 ].…”

“…About 15% of the subjects with cervical dystonia and about 6% of the subjects with blepharospasm have a remission of dystonia [ 185 ]. Unfortunately, most of these subjects relapse within 4 to 5 years [ 185 ]. Furthermore, in some cases, dystonia spreads to other body parts [ 186 ].…”

“…Furthermore, in some cases, dystonia spreads to other body parts [ 186 ]. The factors for remission, relapse, and spread in focal dystonia are not absolutely clear [ 185 , 186 ]. Longitudinal studies in subjects with different forms of dystonia may reveal if olfactory or gustatory decline is a risk factor for these phenomena.…”

Cervical dystonia — improving the effectiveness of botulinum toxin therapy

“…CD significantly reduces quality of life, affects the ability to work, and socially stigmatises patients [2][3]. Spontaneous remission occurs in up to 15% of patients and is usually temporal [5,6], but may be triggered by botulinum neurotoxin type A (BoNT-A) treatment [4]. CD is the most common focal dystonia: a meta-analysis reveals that it affects a mean 4.98 of every 100,000 people.…”

“…However, a significant difference has been observed with regards to geographical location: in Japan the rate is 2.52, whereas in Europe it is 6.71 [5]. www.journals.viamedica.pl/neurologia_neurochirurgia_polska Małgorzata Tyślerowicz et al, Cervical dystonia -improving the effectiveness of botulinum toxin therapy Treatment of CD with BoNT-A is the treatment of choice as recommended by the American Academy of Neurology (AAN), with high effectiveness and safety profiles [6].…”