NCT06411028

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

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

• Status: Recruiting
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: Radboud University Medical Center · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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. 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.

Detailed 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 associations between clinical, electrophysiological, ultrasonographic and (functional) magnetic resonance imaging ((f)MRI) tremor characteristics and BoNT efficacy in DTS of the upper extremity. The secondary objectives are to: * Explore the clinical, electrophysiological, ultrasonographic and (f)MRI differences between DT and TAWD of the upper extremity. * Explore the agreement between a clinical assessment, polymyography (PMG) and muscle ultrasound (MUS) on muscle selection in DTS of the upper extremity. Study design: An uncontrolled multi-centre low-intervention clinical trial where subjects participate for ± 8 months Study population: 60 adults with DTS (± 30 DT/ 30 TAWD) of the upper extremity who start 12-weekly BoNT treatment in normal clinical practice. Main study parameters/endpoints: the associations between clinical, electrophysiological, ultrasonographic, and (f)MRI tremor characteristics at baseline and BoNT efficacy (change in TRG Essential Tremor Rating Assessment Scale (TETRAS) from baseline to 28 weeks). Secondary trial endpoints: * The clinical, electrophysiological, ultrasonographic and (f)MRI differences between DT and TAWD at baseline. * The agreement between a clinical assessment, PMG and MUS on muscle selection. Intervention: Participants are treated with three consecutive BoNT sessions in normal clinical practice. Participants will undergo additional diagnostic procedures: 2 clinical assessments, 2 PMGs, 1 MUS recordings and 1 fMRI assessment and will fill in 2 questionnaires before and after the BoNT sessions.

Conditions

• Dystonic Tremor Syndrome

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Polymyography	We will measure muscle activity using surface electromyography and tremor using inertial measurement units while subjects perform rest, posturing and kinetic tasks.
DIAGNOSTIC_TEST	Muscle ultrasound	We will obtain B-mode images and videos of upper extremity muscles of the most affected upper extremity.
DIAGNOSTIC_TEST	(Functional) magnetic resonance imaging	Subjects will undergo (f)MRI scanning involving concurrent electromyography, accelerometry and functional magnetic resonance imaging.
DIAGNOSTIC_TEST	Clinical assessment	We will assess tremor and dystonia severity using clinical scales.
DIAGNOSTIC_TEST	Questionnaires	We will collect patient-reported outcomes.
DRUG	botulinum toxin injection (BTX A)	Three consequetive botulinum toxin injections of the upper extremities

Timeline

• Start date: 2025-01-01
• Primary completion: 2027-05-30
• Completion: 2027-05-30
• First posted: 2024-05-13
• Last updated: 2025-03-24

Locations

3 sites across 1 country: Netherlands