Amlodipine Plus Botulinum Toxin for Focal Dystonia

Study Overview
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Brief Summary
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Objective: To determine if the calcium channel blockers, amlodipine can augment the effect of botulinum toxin injections in the treatment of focal dystonia. Study Population: 20 patients with cervical dystonia Design: Double-bind, placebo-controlled clinical trail. Outcome measures: For patients: dystonia rating scales (Twistrs, Fahn-Marsden dystonia scale, NINDS subjective patient rating scale), and hand grip strength. For healthy volunteers: Amplitude of EDB MEP.

Detailed Description
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Objective: To determine if the calcium channel blocker, amlodipine can augment the effect of botulinum toxin injections in the treatment of focal dystonia. Study Population: 20 patients with cervical dystonia Design: Double-bind, placebo-controlled clinical trail. Outcome measures: dystonia rating scales (TWISTRS)

Official Title
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Trial of Amlodipine Combined With Botulinum Toxin Injections for Focal Dystonia

Conditions
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Focal Dystonia

Intervention / Treatment
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* Drug: Amlodipine plus Botulinum toxin


Participation Criteria
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Eligibility Criteria
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INCLUSION CRITERIA: Patients enrolled in Protocol 85-N-0195, Efficacy and Pathophysiology of Botulinum Toxin for Treatment of Involuntary Movement Disorders are eligible for enrollment if they meet the following inclusion and exclusion criteria. Good general health Focal hand dystonia or cervical dystonia Stable response to botulinum toxin demonstrated through a series of at least 3 injections over a period of at least a year Benefit from the 3 immediately prior btx injections rated as 75% or less or a duration of benefit lasting less than or equal to 2 months No other medications for dystonia EXCLUSION CRITERIA: Cervical dystonia accompanied by dysphagia or dyspnea, either before or with botulinum toxin injection Present or past cardiac disease, hypertension, arrhythmia or congestive heart failure Anterocollis or other neck dystonia requiring bilateral anterior neck muscle injections Use of concomitant medications affecting calcium channels or those metabolized by the cytochrome p450 3A4 system including grapefruit juice, St. John's wort, HIV protease inhibitors, cimetidine, antibiotics (macrolides, fluoroquinones, antifungal, rifampin), antidepressants (fluvoxamine, norfluoxetine), barbiturates, anticonvulsants (carbamazepine, phenytoin), oral diabetes agents (pioglitazone, troglitazone), and glucocorticoids Allergy to amlodipine or related compounds Pregnany/ nursing Age less than 18 years of age Abnormal EKG Abnormal coagulation profile or liver function tests Use of anticoagulants

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: cervical dystonia<br>cervical dsytonia patinets | Drug: Amlodipine plus Botulinum toxin<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Toronto Western Spasmodic Torticollis Rating Scale (TWSTR) Sum Score | Rating scale assessing sum of severity of dystonia, disability score and pain scale. Ordinal scale ranging from 0 (least severe) to 30 (maximally severe). Score is maximal response TWSTR rating minus baseline rating. | 1-2 month maximal rating | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of Response to Botulinum Toxin Injection With Amlodipine and With Placebo | Self reported duration of effect in weeks. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Writer's Cramp, Calcium Channel Antagonists, Torticollis, Chemodenervation