CompletedNCT00773253Updated Mar 23, 2020Results posted

Botox for Cervical Dystonia Following EMG Mapping

A Phase 4 interventional study of Botulinum toxin A in Cervical Dystonia, sponsored by University of California, San Francisco. Completed at 1 site in United States. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2020-03-23.

Sponsored by University of California, San Francisco · Phase 4, Interventional, and Treatment

Phase: Phase 4
Study type: Interventional
Enrollment: 10
Allocation: Randomized
Ages: 18 Years to 75 Years
Sex: All

Study summary

The purpose of this study is to determine how to improve treatment of patients with cervical dystonia who have not been helped with standard Botox injections. This study is for patients with cervical dystonia who have not benefited from treatment with Botox using conventional "single lead electromyographic (EMG) techniques" for injection. The study aim is to see if these patients may have significantly more benefit if their Botox is injected into muscles that have been chosen with a multi-channel EMG mapping study of the neck prior to Botox injection.

Read the detailed description

The most common type of primary late-onset dystonia is cervical dystonia. Botulinum toxin A (BTX-A) injections are a safe and effective treatment for cervical dystonia in a majority of patients, however, a significant minority of patients (between 15 and 25%) have a suboptimal response to Botulinum toxin therapy. It is unclear why some patients do not respond maximally to neurotoxin therapy.

Studies using needle electromyographic "mapping" in the evaluation of cervical dystonia have revealed that clinical examination alone is insufficient for determining which muscles contribute to the dystonic movement. When compared to needle electromyography (EMG) "mapping studies", experienced movement disorders specialists correctly identify only 59% of active muscles and believe that 25% of muscles which upon EMG evaluation are found to be quiescent, are involved in the dystonia. The selection of incorrect muscles for injection of Botulinum toxin may explain why some patients have a sub-optimal response.

This study seeks to measure outcomes when the muscles involved in dystonia are identified using "mapping" via an 8-12 channel EMG. In the proposed study, the most involved/active dystonic muscles will be correctly identified through simultaneous 8-12 channel mapping resulting in a more informed injection strategy, which may improve response to Botulinum toxin A treatment as compared to single lead EMG based injections. This study changes routine clinical care only by adding the step of studying the muscles of the neck with simultaneous EMG mapping to allow a more objective injection strategy.

Conditions studied

Cervical Dystonia

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Keywords

dystonia
cervical dystonia
Botox
idiopathic primary cervical dystonia

In context

Dystonia

319 studies on the registry are indexed under Dystonia; 56 are open to participants now.

This study's enrollment of 10 is below the median of 32 across 181 interventional studies indexed under Dystonia.

Browse Dystonia studies →

Lead sponsor

University of California, San Francisco is the lead sponsor of 2,132 studies on the registry; 375 are open to participants now.

Of its 262 completed or terminated interventional studies of FDA-regulated products, 196 (75%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years to 75 Years
Sexes eligible: All
Accepts healthy volunteers: No

Inclusion criteria

Male or female subjects, 18 to 75 years of age.
Ability to follow study instructions and complete all required visits.
Subject meets diagnostic criteria for idiopathic primary cervical dystonia.
Subject has at least moderate severity Cervical Dystonia, with a baseline rating of at least 30 on the total TWSTRS and at least 15 on the TWSTRS motor severity subsection.
Patients have had a suboptimal response to 2 previous Botulinum toxin injections at an outside facility.
Patients will not have received Botulinum toxin within 16 weeks of the start of the study.
In order to not confound the clinical response to BTX-A injections, all patients enrolled must have been on a stable medication regimen for 30 days. If they are not on medication at the initiation of the study, they will not be started on medication. Patients must be on the same medication regimen through the entire study including assessment of both single lead EMG based injections and "mapping" based injections. Medications cannot be stopped during the study to avoid confounding the clinical response to BTX-A.

Exclusion criteria

Exclusion Criteria:

Known allergy or sensitivity to any of the components in BTX-A.
Uncontrolled clinically significant medical condition other than the condition under evaluation
Females with a positive pregnancy test, or who are breast-feeding, planning a pregnancy during the study, who think that they may be pregnant at the start of the study or females of childbearing potential who are unable or unwilling to use a reliable form of contraception during the study.
Participation in another medication or device study or within 3 months of enrollment in this study.
Patients know to have a positive frontalis test or have previously tested positive for the presence of BTX-A antibodies will be excluded.
Any known evidence of cervical contractures or significant spinal deformity.

Study design

Phase: Phase 4
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover assignment
Masking: None (open label)
Enrollment: 10 participants (actual)

Study arms

Active comparator
standard EMG-guided Botox injection
All patients will undergo injection using conventional single channel EMG-guided technique. This will be used as a baseline for multi-channel mapping-based injections. Patients will be randomized to undergo single-channel vs. multi-channel assessment upon study entry and will then cross over to the alternate arm.
Drug: Botulinum toxin A
Experimental
Multi-channel EMG-guided Botox injection
Patients will receive multi-channel EMG-guided Botox injection before or after they have been treated with single-channel EMG-guided Botox, depending on which group they are assigned in the cross-over design.
Drug: Botulinum toxin A

Interventions

DrugBotulinum toxin A
All patients will be treated with Botox using both single-channel and multi-channel EMG mapping.
Also known as: Botox

What researchers measure

Primary outcomes

Pre- and Post-injection Toronto Western Spasmodic Torticollis Rating Scale(TWSTRS): Global Clinical Impression Scale (GCI); Visual Analog Scale(VAS)
Time frame: pre-injection, week 16, 20, 36, and 40
Mean Percentage Change in Total Toronto Western Spasmodic Torticollis Rating Scale
Mean Percentage change in Toronto Western Spasmodic Torticollis Rating Scale. This scale ranges from 0 (normal) to 85 (very severe).
Time frame: baseline and 48 weeks

Results

Posted Oct 13, 2011

Limitations and caveats

One patient received single channel injection, but did not get multi-channel injection because the frontalis test showed immunity to botulinum toxin indicating no possibility of clinical benefit. This is an exclusion criterion.

Participant flow

First Intervention (Week 0-24)

Participant flow — First Intervention (Week 0-24)
Milestone	Standard EMG Guided Injections Then Multi-channel Injections	Multi-channel EMG-guided Botox Injection Then Standard EMG Inj
Started	5	5
Completed	5	4
Not completed	0	1
Withdrew: Frontalis test negative	0	1

Second Intervention (Week 24-48)

Participant flow — Second Intervention (Week 24-48)
Milestone	Standard EMG Guided Injections Then Multi-channel Injections	Multi-channel EMG-guided Botox Injection Then Standard EMG Inj
Started	5	4
Completed	5	4
Not completed	0	0

Outcome measures

PrimaryPre- and Post-injection Toronto Western Spasmodic Torticollis Rating Scale(TWSTRS): Global Clinical Impression Scale (GCI); Visual Analog Scale(VAS)

Time frame:: pre-injection, week 16, 20, 36, and 40

No measurements were reported for this outcome.

PrimaryMean Percentage Change in Total Toronto Western Spasmodic Torticollis Rating Scale

Mean Percentage change in Toronto Western Spasmodic Torticollis Rating Scale. This scale ranges from 0 (normal) to 85 (very severe).

Time frame:: baseline and 48 weeks
Reported as:: Mean · percent change

Mean Percentage Change in Total Toronto Western Spasmodic Torticollis Rating Scale
percent change	Standard EMG Guided Injections	Multi-channel EMG-guided Botox Injection
Mean Percentage Change in Total Toronto Western Spasmodic Torticollis Rating Scale	9 ± 20.8	23.5 ± 15.7

Adverse events

Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
Standard EMG Guided Injections	—	0/9 (0%)	0/9 (0%)
Multi-channel EMG-guided Botox Injection	—	0/10 (0%)	0/10 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)	Standard EMG Guided Injections Then Multi-channel	Multi-channel EMG-guided Botox Injection Then Single Channel	Total
<=18 years	0	0	0
Between 18 and 65 years	5	5	10
>=65 years	0	0	0

Age, Continuous
Age, Continuous(years)	Standard EMG Guided Injections Then Multi-channel	Multi-channel EMG-guided Botox Injection Then Single Channel	Total
Mean	55.4 ± 5.2	54.7 ± 5.1	55.4 ± 5.2

Sex: Female, Male
Sex: Female, Male(Participants)	Standard EMG Guided Injections Then Multi-channel	Multi-channel EMG-guided Botox Injection Then Single Channel	Total
Female	2	2	4
Male	3	3	6

Region of Enrollment
Region of Enrollment(participants)	Standard EMG Guided Injections Then Multi-channel	Multi-channel EMG-guided Botox Injection Then Single Channel	Total
United States	5	5	10

Study locations

1 site

University of California, San Francisco
San Francisco, California 94143, United States

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Mar 23, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT00773253
Lead sponsor: University of California, San Francisco
Collaborators: Allergan
Responsible party: Sponsor
First posted: Oct 16, 2008
Start date: Apr 2008
Primary completion: Oct 2010
Completion: Jan 2011
Results posted: Oct 13, 2011
Last update: Mar 23, 2020

Study contacts

Graham A. Glass, M.D.

principal investigator · University of California, San Francisco

Oversight

Data monitoring committee: No

View the source record on ClinicalTrials.gov ↗

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