Comparison of Botulinum Toxin Injections in Forearm FLexor Plus EXtensor Muscles vs. Flexor Muscles Alone for Treatment of Essential Hand Tremor(FLEX-D ET)

Study Overview
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Brief Summary
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To compare the efficacy of botulinum toxin (BoNT) injections in forearm flexors plus extensor muscles versus flexors alone for the treatment of essential hand tremor (ET).

Detailed Description
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The investigators propose a pilot, single center, double blind, randomized, parallel, placebo controlled trial comparing 2 (BoNT) injection patterns for treatment of moderate to severe essential tremor. The investigators will recruit 20 patients with (ET).

Official Title
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Comparison of Botulinum Toxin Injections in Forearm FLexor Plus EXtensor Muscles Versus Flexor Muscles Alone for the Treatment of Essential Hand Tremor (FLEX-D ET)

Conditions
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Essential Tremor

Intervention / Treatment
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* Drug: Botulinum toxin
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 and over, male or female patient with (ET) involving at least their dominant hand, as diagnosed by a movement disorders neurologist. Having bothersome hand tremor in dominant hand with a hand TRS ≥2 On stable medications during last 30 days prior to enrollment. Exclusion Criteria: Presence of secondary causes of tremor, such as dystonia and parkinsonism Any contraindication to botulinum toxin injections (e.g. motor neuron disease, neuromuscular junction disease, etc.) History of surgical treatment for (ET). Dementia as defined by DSM-V criteria Patients with suboptimally treated depression and significant depressive symptoms as defined by a PHQ-9 score of ≥15 (PHQ-9 scores 1-4 Minimal depression; 5-9 Mild depression; 10-14 Moderate depression; 15-19 Moderately severe depression; 20-27 Severe depression). Antidepressant medications, prescribed for depression or anxiety, will be allowed if the patient has been on a stable dose for at least 30 days. Patients with suboptimally treated anxiety and significant anxiety symptoms as defined by a GAD-7 score of ≥15 (GAD-7 scores 0-4: minimal anxiety; 5-9: mild anxiety; 10-14: moderate anxiety; 15-21: severe anxiety). Anti-anxiety medications, prescribed for anxiety, will be allowed if the patient has been on a stable dose for at least 30 days. Significant renal, hepatic, cardiac and thyroid disease

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: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 150 units of abobotulinumtoxinA<br>150 units of abobotulinumtoxinA in flexor compartment of dominant arm (75 units in flexor carpi radialis [FCR] and 75 units in flexor carpi ulnaris [FCU]) along with placebo in extensor carpi radialis (ECR) and extensor carpi ulnaris (ECU) | Drug: Botulinum toxin<br>* Botulinum injections into dominant upper extremity using protocol outlined above.<br>* Other names: BoNT;Other: Placebo<br>* Placebo injections in extensor carpi radialis (ECR) and extensor carpi ulnaris (ECU) per protocol outlined above<br>|
| Experimental: 75 units of abobotulinumtoxinA<br>75 units of abobotulinumtoxinA in FCR and FCU and 25 units in ECR and ECU | Drug: Botulinum toxin<br>* Botulinum injections into dominant upper extremity using protocol outlined above.<br>* Other names: BoNT;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in the 6 Week Post Injection Patient Global Impression of Improvement Scale (PGIS) Between Flexors Along and Flexors Plus Extensors Groups. | 6 weeks post injection Clinician Global Impression if improvement Scale (CGIS) Assessment of improvement graded by the patient on a -4 to +4 scale -4 = severe worsening 0 = no change +4 = complete abolishment of symptoms Higher scores represent better outcome. | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in Tremor Rating Scale Score (TSR)Change From Baseline to Week 6 Between Flexors Alone and Flexors Plus Extensors Groups. | TRS: Tremor Rating Scale : scale composed of 6 items rated from 0-4. 0=none/normal and 4 = very severe/high level of disability. Total score is the sum of all items. Max score 24 ( maximal severity of tremor) Minimal score 0= no tremor/normal. | Baseline and 6 weeks | 
| Difference in the 6 Week Post Injection Clinician Global Impression of Improvement Scale (CGIS) Between Flexors Along and Flexors Plus Extensors Groups. | 6 weeks post injection Clinician Global Impression if improvement Scale (CGIS) Assessment of improvement graded by clinician on a -4 to +4 scale -4 = severe worsening 0 = no change +4 = complete abolishment of symptoms Higher scores represent better outcome. | 6 weeks | 
| Difference of the Quality of Life in Essential Tremor Questionnaire (QUEST) Summary Index Change at Week 6 Compared to Baseline Between Wrist Flexors Versus Wrist Flexors Plus Extensors Group. | QUEST( Quality of Life in Essential Tremor Questionnaire ) is a 30-item, ET-specific quality of life scale . Items contribute to five dimensions. Physical/ADL (9 items ), Psychosocial (9 items), Communication (3 items), Hobbies/Leisure (3 items), and Work/Finances (6 items). The score on each scale is expressed as a percentage of the total score possible, with a higher score indicating greater dissatisfaction with that domain of QOL. A total or summary index corresponds to the mean of the five domain scores. The total summary index corresponds to the mean of the five domain scores. Maximal score 100: worse quality of life. Minimal Score 0: best quality of life. This outcome represents the median of the differences between baseline and week 6 in QUEST summary index.Positive index change values indicate that the score increased and negative values indicate that the score decreased. | Baseline and 6 weeks | 
| Difference in the Post Injection Grip Strength Change Between Flexor Only Group and Flexor and Extensors Group at 6 Weeks. | the median of the differences in grip strength between baseline and week 6, A negative value indicates a decrease in grip strength in Kg at week 6. | 6 weeks | 
| 12 Weeks Post Injection Tremor Rating Scale for Flexors Group and Flexors Plus Extensors Group. | TRS: Tremor Rating Scale : scale composed of 6 items rated from 0-4. 0=none or normal and 4 = very severe or high level of disability. Total score is the sum of all items. Max score 24 ( maximal severity of tremor) Minimal score 0= no tremor/normal. | 12 weeks | 
| 12 Week Post Injection in Clinician Global Impression Scale-Improvement Subscale (CGIS) | 12 week post injection in Clinician Global Impression Scale-Improvement Subscale (CGIS) Assessment of improvement graded by the clinician on a -4 to +4 scale -4 = severe worsening 0 = no change +4 = complete abolishment of symptoms Higher scores represent better outcome. | 12 weeks | 
| 12 Week Post Injection Patient Global Impression Scale-Improvement Subscale (PGIS) | Patient Global Impression Scale-Improvement Subscale (PGIS) Assessment of improvement graded by patient on a -4 to +4 scale -4 = severe worsening 0 = no change +4 = complete abolishment of symptoms Higher scores represent better outcome. | 12 weeks | 
| Difference of Quality of Life in Essential Tremor Questionnaire (QUEST) Summary Index Change at Week 12 Compared to Baseline Between Wrist Flexors Versus Wrist Flexors Plus Extensors Group. | QUEST( Quality of Life in Essential Tremor Questionnaire ) is a 30-item, ET-specific quality of life scale . Items contribute to five dimensions. Physical/ADL (9 items ), Psychosocial (9 items), Communication (3 items), Hobbies/Leisure (3 items), and Work/Finances (6 items). The score on each scale is expressed as a percentage of the total score possible, with a higher score indicating greater dissatisfaction with that domain of QOL. A total or summary index corresponds to the mean of the five domain scores. The total summary index corresponds to the mean of the five domain scores. Maximal score 100: worse quality of life. Minimal Score 0: best quality of life. This outcome represents the median of the differences between baseline and week 6 in QUEST summary index. Positive index change values indicate that the score increased and negative values indicate that the score decreased. | Baseline and 12 weeks. |