Incidence of Dysphagia and Comorbidities in Patients with Cervical Dystonia, Analyzed by Botulinum Neurotoxin Treatment Exposure

Dysphagia is prevalent in patients with cervical dystonia (CD) and is a potential adverse event in patients treated with botulinum neurotoxin (BoNT) for CD. Real-world studies may provide a better understanding of the incidence and potential risk factors of dysphagia after BoNT administration. This retrospective cohort study used longitudinal patient-level data from Optum's de-identified Market Clarity Data to evaluate rates of dysphagia in patients with CD exposed and unexposed to BoNT. Patients ≥18 years of age with ≥2 CD diagnoses ≥30 days apart during the study period (1 January 2017-30 September 2021) who had ≥180 days of continuous health plan enrollment prior to the cohort entry date (first CD diagnosis) were included. Overall, the mean (SD) age of all CD patients (Cohort 1; N = 81,884) was 54.00 (16.21) years, and they were mostly female (67.9%) and white (76.96%). BoNT-Exposed patients (Cohort 2; N = 19,244) had a higher incidence of dysphagia (16.3%) and comorbid conditions when compared with BoNT-Unexposed patients (Cohort 3; N = 61,154 [12.1%]). Overall, patients with pre-existing dysphagia, other dystonias, and comorbid neurologic conditions at baseline also had higher proportions of dysphagia. This real-world analysis indicates that comorbid conditions predispose patients with CD to a greater dysphagia risk during treatment.