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

Dystonia Clinical Trial

Official title: Factors Determining the Efficacy of Botulinum Toxin for Arm Tremor in Dystonia: An Exploratory Study

Status Not yet recruiting

Clinical Trial Summary

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. We aim to explore the associations between clinical and pathophysiological tremor characteristics and BoNT efficacy. To do so, we will 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.

Clinical Trial Description

Rationale: 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 from BoNT treatment. This highlights the need for personalized treatment.

Objective: The primary objective is to explore the differences in BoNT efficacy between DT and TAWD of the upper extremity. Secondary objectives are to: explore the electrophysiological and cerebral differences between DT and TAWD of the upper extremity, explore the associations between clinical, electrophysiological, ultrasonographic and (functional) magnetic resonance imaging ((f)MRI) tremor characteristics and BoNT efficacy in DTS of the upper extremity, and explore the agreement between a clinical assessment, polymyography (PMG) and muscle ultrasound (MUS) on muscle selection in DTS of the upper extremity.

Study design: Explorative prospective multi-centre cohort study Study population: 60 adults with DTS (± 30 DT/ 30 TAWD) of the upper extremity who start 12-weekly BoNT treatment as part of standard care.

Main study parameters/endpoints: The primary outcome measure is clinical tremor severity quantified by the TRG Essential Tremor Rating Assessment Scale (TETRAS) at 28 weeks. We will also collect clinical, electrophysiological, ultrasonographic and (f)MRI measures and patient-reported outcomes.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Subjects do not benefit from participation. The risk of the extra study procedures is negligible. The study procedures are harmless, but may be tiring. The time burden consists of five extra hours spent at the hospital divided across three visits and filling in questionnaires (one hour). The baseline visit for MRI scanning and the visit at 28 weeks are extra compared to standard care. ;

Related Conditions & MeSH terms

• Dystonia
• Dystonic Disorders
• Tremor

• NCT number: NCT06411028
• Study type: Observational
• Source: Radboud University Medical Center
• Contact: Iris Visser, MSc
• Phone: +31 024 361 66 00
• Email: iris.visser@radboudumc.nl
• Status: Not yet recruiting
• Start date: July 1, 2024
• Completion date: May 30, 2027