Botox Injections in Non-Cranial Nerve VII Innervated Muscles for Facial Synkinesis

NCT07295288 | Not Yet Recruiting Phase 4

• 1 other identifier: 251490
• Study Type: interventional
• Target: 50
• Locations: 0 countries
• Sites: N/A

Brief Summary

Facial synkinesis is a condition that occurs following facial nerve (CN7) injury, typically secondary to Bell's palsy, trauma, surgery (e.g., acoustic neuroma resection), or malignancy. Synkinesis is due to aberrant regeneration of the facial nerve, where axons regrow improperly and result in misdirected innervation of facial muscles. This results in involuntary, uncoordinated muscle movements, where activation of one muscle group triggers unintended contractions in others. Standard treatment of facial synkinesis involves botulinum toxin (BT) injections into muscles controlled by CN7 to reduce these unwanted movements. However, patients often anecdotally report that adding BT injections into non-CN7 innervated muscle groups, such as the masseter and temporalis muscles, improve their synkinesis symptoms. This study therefore aims to assess whether adding BT injections to non-CN7 innervated muscle groups, specifically the masseter and temporalis muscle, can improve treatment outcomes for people with facial synkinesis. This study will use a crossover design, where each participant will serve as their own control to compare treatment effects. In the first treatment arm, patients will receive only their standard BT injections into muscle groups controlled by CN7 - no other muscles will be treated. In the second treatment arm, will receive the same standard BT injections in CN7 muscles, plus additional injections into masseter and temporalis muscles. Patients will be randomized to a specific treatment arm at their first visit. At their second visit, they will be randomized to the other treatment arm, in standard crossover study design. Pre- and post-treatment surveys will be collected to assess the benefit of adding non-CN7 muscle groups.

Conditions

Synkinesis

Keywords

botulinum toxin

Outcome Measures

Primary Outcomes (3)

• Synkinesis Assessment Questionnaire (SAQ)

  This 9-item questionnaire assesses functional status (hyperactive and/or inappropriately active facial muscles) related to facial synkinesis and is already given at each clinic visit as a routine part of clinical practice. The survey is well validated for evaluating synkinesis symptoms in patients with facial nerve injury. SAQ scale: 1 = seldom or not at all, 2 = occasionally, or very mildly, 3 = sometimes, or mildly, 4 = most of the time, or moderately, 5 = all the time, or severely

  Pre-treatment and repeated 5 weeks post-treatment

• Headache Impact Test (HIT-6)

  This 6-item questionnaire seeks to understand the severity of headaches and impact on every-day quality of life. The survey is widely validated for assessing headache symptom and burden. We plan to add in 3 additional questions to this survey including 1) how often do you experience headaches (1 = never or rarely, 2 = 1-2 days a week, 3 = 3-4 days a week, 4 = nearly every day), 2) on a scale of 1-10 (10 = most severe) how severe are your headaches, and 3) I feel as if my Botox injections improved my headaches (Y/N). HIT-6 Scale: 1 = Never 2 = Rarely 3 = Sometimes 4 = Very often 5 = Always

  Pre-treatment and repeated 5 weeks post-treatment

• Temporomandibular Disorder Questionnare (TMD-7)

  This 7-item questionnaire assesses symptoms related to temporomandibular mandibular joint (TMJ) disorder. It asks about jaw pain, tightness, clicking and difficulty eating, among other things. We plan to add in 3 additional questions to this survey including 1) how often do you experience jaw pain/tightness (1 = never or rarely, 2 = 1-2 days a week, 3 = 3-4 days a week, 4 = nearly every day), 2) on a scale of 1-10 (10 = most severe) how severe is your jaw pain/tightness, and 3) I feel as if my Botox injections improved my jaw pain/tightness (Y/N). TMD-7 Scale: 1 = Rarely or Never 2 = A few times a month 3 = Once or Twice a Week 4 = Nearly Every Day

  Pre-treatment and repeated 5 weeks post-treatment

Study Arms (2)

Even MRN

OTHER

Patients with MRNs ending in an even number will undergo their standard BT injections (CN7 muscle groups only) + non-CN7 muscle groups at their first treatment session, followed by standard BT injections alone at their second treatment session.

Drug: Botulinum Toxin Type A Injection [Botox]

Odd MRN

OTHER

Patients with MRNs that end in an odd number will undergo the reverse injection process (standard BT injections alone at first treatment session, followed by standard BT injections + non-CN7 muscle groups at their second treatment session).

Drug: Botulinum Toxin Type A Injection [Botox]

Interventions

Botulinum Toxin Type A Injection [Botox] DRUG

Patients will receive standard of care synkinesis treatment. Depending on the treatment arm, they will receive additional botox injections to temporalis and masseter muscle groups which will only be injected on the ipsilateral side to the facial nerve injury. Decision to include the temporalis and/or masseter muscles will be based on each patients response to screening questions regarding jaw pain/tightness or headaches.

Even MRN; Odd MRN

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age \> 18 years.
• Current diagnosis of facial synkinesis due to facial nerve paralysis/paresis.
• Scheduled to undergo BT injection for management of facial synkinesis.
• Have undergone \> 3 prior BT injection sessions at VUMC for facial synkinesis.
• Able to read and understand English.
• Symptoms of neck tightness, jaw tightness, or headaches.

You may not qualify if:

• Cognitive impairment that would preclude the ability to provide informed consent
• Unable to read text on a written survey or computer screen

Sponsors & Collaborators

• Vanderbilt University Medical Center: lead

MeSH Terms

Conditions

Synkinesis

Interventions

Botulinum Toxins, Type A

Condition Hierarchy (Ancestors)

Dyskinesias; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Hydrolases; Enzymes; Enzymes and Coenzymes; Metalloproteases; Bacterial Proteins; Proteins; Amino Acids, Peptides, and Proteins; Bacterial Toxins; Toxins, Biological; Biological Factors

Study Officials

• Priyesh Patel, MD

  VUMC

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Christine Little, MD

CONTACT

6504555258; christine.little@vumc.org

Amy Wang

CONTACT

2818859243; amy.wang@vumc.org

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: The study design is a prospective crossover study. Patients who meet eligibility criteria and wish to proceed with the study will be randomized into two groups based on their MRN numbers. Patients with MRNs ending in an even number will undergo their standard BT injections (CN7 muscle groups only) + non-CN7 muscle groups at their first treatment session, followed by standard BT injections alone at their second treatment session. Patients with MRNs that end in an odd number will undergo the reverse injection process (standard BT injections alone at first treatment session, followed by standard BT injections + non-CN7 muscle groups at their second treatment session).

Study Record Dates

• First Submitted: December 7, 2025
• First Posted: December 19, 2025
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): June 30, 2027
• Last Updated: April 15, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share