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NCT Number: NCT07140874

Zinc as an Adjunctive Therapy for Cervical Dystonia

The goal of this clinical trial is to evaluate if supplemental zinc can prolong the duration of benefit of botulinum toxin injections in cervical dystonia patients receiving care at the University of Florida.

The main aims are:

1. To evaluate the efficacy of zinc citrate supplementation in prolonging the duration of symptom relief provided by botulinum toxin type A (Botox) injections in cervical dystonia patients. 2. To assess the safety and tolerability of zinc supplementation in this patient population. 3. To analyze the potential influence of zinc supplementation on the quality of life and functional outcomes in cervical dystonia patients receiving Botox.

Researchers will compare zinc citrate to a placebo (a look-alike substance that contains no active drug) to see if zinc works to extend the effects of Botox.

Participants will:

Take zinc citrate or a placebo every day for 3 months, then cross over to the alternative treatment for another 3 months.

Visit the clinic every 3 months for Botox injections, check ups and surveys.

Recruiting

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Key information

Conditions

Cervical Dystonia Dyskinesias Dystonia Neurologic Manifestations Pathological Conditions, Signs and Symptoms Signs and Symptoms Torticollis

Age range

18 year–89 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Norman Fixel Institute for Neurological Diseases

Gainesville, Florida, 32608, United States

Location status: Recruiting

About this study

Study Design:

  • Randomized, single-blind, crossover placebo-controlled trial.
  • Participants: Approximately 20 patients diagnosed with cervical dystonia and currently receiving botulinum toxin (BoNT) type A (Botox) injections at the University of Florida (UF) Movement Disorders Clinic with good response to treatment as determined by treating neurologist will be enrolled into this study. The investigators plan to screen 25 patients to allow for screen failures and withdrawals.
  • Intervention: Participants will be randomized to receive either zinc citrate 30 mg supplementation or placebo starting immediately after their scheduled BoNT injection for 3 months. At a follow up BoNT injection, they will receive the alternative treatment for another 3 months. The total observation period is 6 months. Standard time between BoNT injections is 3 months.

The UF Movement Disorders Clinic follows approximately 1,500 cervical dystonia patients a year. The investigators do not anticipate any recruitment challenges.

Participants will be recruited during neurology clinic appointments and screening clinic appointments.

  • Patients will receive the same pattern of BoNT injections (muscle selection and dose) during the duration of the study.
  • Blood serum levels of zinc and vitamin B12 and complete blood counts (CBCs) will be measured at baseline and at the end of the study. Participants will be sent to UF Health Medical lab for blood draws and sample collection.
  • Written informed consent will be obtained from each participant before any study-specific procedures or assessments are performed.

Inclusion criteria

  • Adults aged 18-89 years.
  • Diagnosed with cervical dystonia.
  • Receiving regular BoNT type A (Botox) injections for at least six months.

Exclusion criteria

  • Known allergy or intolerance to zinc.
  • Significant comorbidities or concurrent medications that could interfere with study outcomes.
  • Pregnant or breastfeeding women.
  • Already taking a zinc supplement which would exceed tolerable upper intake level in adults (40 mg elemental zinc per day) with addition of zinc study supplement

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged 18-89 years.
  • Diagnosed with cervical dystonia.
  • Receiving regular BoNT type A (Botox) injections for at least six months.

Exclusion criteria

  • Known allergy or intolerance to zinc.
  • Significant comorbidities or concurrent medications that could interfere with study outcomes.
  • Pregnant or breastfeeding women.
  • Already taking a zinc supplement which would exceed tolerable upper intake level in adults (40 mg elemental zinc per day) with addition of zinc study supplement.

Treatment and study plan

Zinc citrate

Drug

Oral zinc citrate 30 mg daily

Placebo

Drug

Placebo

Primary outcomes

  1. Duration of Botox efficacy

    Time frame: 3 and 6 months post intervention

    Time to return to baseline symptom severity using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Severity Subscale. The TWSTRS Severity Subscale is scored from 0 to 35, with higher numbers indicating a more severe condition.

Secondary outcomes

  1. Change in Pain Severity

    Time frame: 3 and 6 months post intervention

    Change in pain severity as measured by the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Pain Subscale. The TWSTRS Pain Subscale is scored from 0 to 20, with higher numbers indicating a more painful condition.

  2. Change in Quality of Life

    Time frame: 3 and 6 months post intervention

    Change in quality of life as measured by the Craniocervical dystonia questionnaire (CDQ-24). The CDQ-24 contains 24 items pertaining to quality of life in patients with cervical dystonia, scored from 0 ("never") to 4 ("very severely").

  3. Change in Functional Disability

    Time frame: 3 and 6 months post intervention

    Change in functional disability as measured by the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Disability Subscale. The TWSTRS Disability Subscale is scored from 0 to 30 with higher numbers indicating a more disabling condition.

  4. Patient Global Impression of Change

    Time frame: 3 and 6 months post intervention

    Patient Global Impression of Change (PGIC) measures the patient's perception of the change in their condition after treatment, scored from 1 ("Very much improved") to 7 ("Very much worse").

  5. Clinician Global Impression of Change

    Time frame: 3 and 6 months post intervention

    The Clinician Global Impression of Change (CGIC) measures the researcher's perception of the change in the patient's condition after treatment, scored from 1 ("Very much improved") to 7 ("Very much worse").

Interested in participating?

Recruiting

Interested in participating?

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Sponsors and collaborators

Lead sponsor

University of Florida

Other

Registry information

Official study title

Evaluation of Supplemental Zinc as an Adjunct to Prolong the Duration of Benefit After Botulinum Toxin Injections in Subjects With Cervical Dystonia

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Aug 26, 2025
Registry last updated
May 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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