MRI-Guided Focused Ultrasound in Cervical Dystonia

Abstract

Introduction. MRI-guided focused ultrasound (MRgFUS) is approved for management of various movement disorders, primarily essential tremor and Parkinson’s disease (PD), with favorable long-term outcomes in numerous patients worldwide. However, few case studies describe the use of this modality for symptomatic treatment of dystonias that, as the third most common movement disorder, may be rather disabling. Objective: To improve outcomes in patients with cervical dystonia (CD) using MRgFUS. Materials and methods. We retrospectively analyzed 13 cases of various CD types managed with MRgFUS in single or multiple sessions. The mean age of the patients was 42 [39; 53] years. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was used to assess patients' statuses and severity of CD symptoms during therapy and the last available observation period. The targets included the pallidothalamic tract and the thalamic ventral oralis complex nucleus or their combination. Results. The mean follow-up period was 13.3 ± 3.4 months (July 2021 to April 2023). The mean CD severity sum score (TWSTRS score) was 22 [16; 25] before MRgFUS and 6 [4; 9] in the last observation. Therefore, we report 70.6% [55.6; 76.5] improvement (paired samples t-test p = 0.0025). Conclusion. Available data evidence that MRgFUS is efficient and sufficiently safe for symptomatic treatment in pharmacoresistant CD patients. A number of vital aspects of MRgFUS have to be specified in larger CD cohorts in the long-term follow-up.

Keywords

• mri-guided focused ultrasound
• cervical dystonia
• thalamic ventral oralis complex nucleus
• pallidothalamic tract
• ventral interposed nucleus
• pallidothalamic tractotomy