Dystonia treatment: Patterns of medication use in an international cohort

Abstract

Objective: To determine the frequency of medication use in patients with dystonia enrolled in an international biorepository study.

Methods: In a cross-sectional analysis, we included 2,026 participants enrolled at 37 sites in the United States, Canada, Europe, and Australia through Project 1 of the Dystonia Coalition, an international biorepository study. The primary aim was to assess the frequency of medication classes recommended for treating patients with dystonia, and the secondary aim was to compare characteristics (disease type, age, sex, duration of disease, comorbid conditions, severity).

Results: Querying the database for the presence of any medication for dystonia used (includes both injectable and oral therapy), we found 73% using medications (n = 1,488) and 27% using no dystonia medications (n = 538). Furthermore, 61% of the total sample used botulinum toxin (BoNT) therapy alone or in combination. Differences were found in medication use patterns by dystonia type, with the lowest oral medication use in focal dystonia and highest use in generalized dystonia; by region, with highest BoNT therapy rate reported in Italy and the lowest in the Northeast region of the United States; and by focal dystonia subtype, with highest BoNT therapy alone in blepharospasm and spasmodic dysphonia (49%) and lowest in other cranial dystonia (32%).

Conclusions: The majority of patients with dystonia enrolled in the Dystonia Coalition Project 1 were using medications to treat their dystonia. Overall, a complex picture of medication use patterns emerged, with factors such as region, disease duration, type of dystonia, disease severity, and psychiatric comorbidities all playing a significant role.

Figure 1. Medication use by dystonia type and subtype

Main graph shows medication use by dystonia type (n = 2,001 with 25 missing values) with percentage used along the y-axis. Inset shows percentage of no medication use and medication use by class for each subtype of focal dystonia (n = 1,528 with 473 nonfocal dystonia and 25 missing). Other cranial includes lower cranial dystonia and Meige syndrome. For each focal dystonia subtype, percentages for none, oral, botulinum toxin (BoNT), and BoNT plus oral: blepharospasm, 23.6%, 5.5%, 48.8%, and 22.1%, respectively; other cranial, 25.8%, 14.4%, 31.8%, and 28.0%; cervical, 23.4%, 12.2%, 34.3%, and 30.1%; laryngeal, 37.9%, 5.5%, 48.9%, and 7.7%; and limb, 36.3%, 10.2%, 40.1%, and 13.4%.

Figure 2. Dystonia medication use plotted by region

The individual region plots are approximately scaled to reflect number of participants in each region (actual numbers: Northeast n = 145; Midwest n = 477; South n = 782; West n = 184; Canada n = 72; Australia n = 19; France n = 130; Germany n = 158; Italy n = 56; England excluded because of small number [n = 3]; p < 0.0001). BoNT = botulinum toxin.

Figure 3. Medication use by class

Percent of participants taking each class of medications. Participants may be taking more than one medication. Medication class use varied by dystonia type (*p < 0.05), by focal dystonia subtype (**p < 0.05), and by presence of anxiety/depression (^p < 0.05). BoNT = botulinum toxin.