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

Phase 4
Recruiting
Conditions
Dystonic Tremor Syndrome
Interventions
Diagnostic Test: Polymyography
Diagnostic Test: Muscle ultrasound
Diagnostic Test: (Functional) magnetic resonance imaging
Diagnostic Test: Clinical assessment
Diagnostic Test: Questionnaires
Drug: botulinum toxin injection (BTX A)
Registration Number
NCT06411028
Lead Sponsor
Radboud University Medical Center
Brief 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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
60
Inclusion Criteria
  • Clinical diagnosis of dystonic tremor or tremor associated with dystonia according to the 2018 consensus statement on the classification of tremors
  • Tremor of one or both upper extremities
  • Starting botulinum toxin injections as part of normal clinical practice
  • Age ≥ 18 years
Exclusion Criteria
  • Acquired aetiology of dystonic tremor syndrome
  • Previous botulinum toxin treatment of the to be treated upper extremity for ≥ 4 consecutive sessions
  • In case of previous botulinum toxin treatment of the to be treated upper extremity for ≤3 consecutive sessions: the last botulinum toxin injections ≤ 6 months before study enrolment
  • Unstable dose medications for dystonia and tremor ≤ 1 month before study enrolment
  • Deep brain stimulation implantation ≤ 6 months before study enrolment
  • Unstable deep brain stimulation variables ≤ 1 month before study enrolment
  • Comorbidity interfering with study participation
  • Known hypersensitivity for components of Dysport
  • Infection at the upper extremity
  • Pregnancy, trying to conceive and breastfeeding
  • Insufficient knowledge of the Dutch or English language

Exclusion criteria for MRI scanning:

  • Contraindications for MRI (e.g. previous brain surgery, claustrophobia, active implant, epilepsy, metal objects in the upper body that are incompatible with MRI)
  • Moderate to severe head tremor while lying supine (to avoid artefacts caused by extensive head motion during scanning).
  • Inability to provoke postural tremor while lying supine.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Botulinum toxinPolymyographyParticipants are treated with three consecutive BoNT sessions.
Botulinum toxinMuscle ultrasoundParticipants are treated with three consecutive BoNT sessions.
Botulinum toxin(Functional) magnetic resonance imagingParticipants are treated with three consecutive BoNT sessions.
Botulinum toxinClinical assessmentParticipants are treated with three consecutive BoNT sessions.
Botulinum toxinQuestionnairesParticipants are treated with three consecutive BoNT sessions.
Botulinum toxinbotulinum toxin injection (BTX A)Participants are treated with three consecutive BoNT sessions.
Primary Outcome Measures
NameTimeMethod
Tremor severity assessed by the TRG Essential Tremor Rating Assessment Scale (TETRAS)Baseline, 28 weeks

The primary outcome is the clinical tremor severity measured by the TRG Essential Tremor Rating Assessment Scale (TETRAS) at 28 weeks. The scale ranges between 0 and 112 points, with higher scores indicating a more severe tremor. The TETRAS consists of two subcategories: a 12-item activities of daily living subscale and a 9-item performance scale. The daily living subscale is scored by interviewing the participant. The performance scale is rated by observing the participants while they are performing multiple tasks.

Secondary Outcome Measures
NameTimeMethod
Tremor severity assessed by the Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS)Baseline, 28 weeks

FTM-TRS \[0-152\]: higher scores indicate a more severe tremor.

Dystonia severity assessed by the Burke-Fahn-Marsden Dystonia Rating Scale (BFM-DRS)Baseline, 28 weeks

BFM-DRS \[0-150\]: higher scores indicate more severe dystonia.

Additional neurological signs assessed by the Standardised Tremor Elements Assessment (STEA)Baseline

STEA \[0-27\]: higher scores make a diagnosis of dystonic tremor syndrome instead of essential tremor more likely.

Quality of life assessed by the Quality of Life Essential Tremor Questionnaire (QUEST)Baseline, 28 weeks

QUEST \[0-120\]: higher scores indicate greater dissatisfaction.

Psychological stress assessed by the Perceived stress scale (PSS)Baseline, 28 weeks

PSS \[0-4\]: higher scores indicate higher levels of perceived stress

Pain assessed by the Numeric Pain Rating Scale (NPRS)Baseline, 28 weeks

NPRS \[0-10\]: 0 indicates no pain and 10 the worst imaginable pain

Patient-reported change in tremor severity assessed by the Patient Global Impression of Change (PGIC)28 weeks

PGIC \[-3: much worse, -2: moderately worse, -1: slightly worse, 0: no change, 1: slightly better, 2: moderately better, 3: much better\]

Electrophysiological characteristicsBaseline, 28 weeks

e.g. tremor power, dominant frequency, frequency-width at half-width power, intermuscular coherence, tremulous muscles

Ultrasonographic tremulous activityBaseline
Tremor related cerebral activityBaseline

Quantified using functional MRI scanning

Botulinum toxin parametersBaseline, 12 and 24 weeks

e.g. injection schemes, rationale for muscle selection, adherence

Trial Locations

Locations (3)

Donders Centre for Cognitive Neuroimaging

🇳🇱

Nijmegen, Gelderland, Netherlands

Radboud University Medical Center

🇳🇱

Nijmegen, Gelderland, Netherlands

Canisius-Wilhelmina Ziekenhuis

🇳🇱

Nijmegen, Gelderland, Netherlands

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