Factors Determining the Efficacy of Botulinum Toxin for Arm Tremor in Dystonia

Tremor occurs in up to 55% of dystonia patients, which is known as dystonic tremor syndrome (DTS). Tremor can be present in the body part affected by dystonia (dystonic tremor, DT), or an unaffected body part (tremor associated with dystonia, TAWD). DTS can be treated with botulinum neurotoxin (BoNT) injections, but BoNT is effective in only about 60-70% of patients. It is unknown which patients benefit most from BoNT treatment. The investigators aim to explore the associations between clinical and pathophysiological tremor characteristics and BoNT efficacy. To do so, the investigatorswill measure clinical, electrophysiological, ultrasonographic and (functional) magnetic resonance imaging ((f)MRI) characteristics before the start of BoNT treatment and measure BoNT efficacy after three three-monthly BoNT sessions.

NCT Number	NCT06411028
Lead Sponsor	Radboud University Medical Center Collaborators: Canisius-Wilhelmina Hospital, Donders Centre for Cognitive Neuroimaging
Conditions	Dystonic Tremor Syndrome
Enrollment	60 participants
Start Date	2025-01-01
Primary Completion	2027-01-30 (estimated)
Study Completion	2027-01-30 (estimated)
Updated on ClinicalTrials.gov	2026-08-14