Electromyography-guided Botulinum Toxin Injections for Treatment of Facial Synkinesis: A Pilot Study

Saturday, October 17, 2026

2:48 PM - 2:54 PM PT

Location: 404A

Presenting Author(s)

CL

Christine C. Little, MD

Christine C. Little
Vanderbilt University
Nashville, Tennessee, United States

Co-Author(s)

Montana K. Upton, MD

Montana Upton
Indiana University School of Medicine
Nashville, TN, United States
AB

Alexander J. Barna, MD, MPH

Otolaryngology - Head & Neck Surgery Resident
Cleveland Clinic Foundation
Cleveland, OH, United States
SS

Scott J. Stephan, MD

Scott Stephan
Vanderbilt University Medical Center
Nashville, TN, United States
JG

Jordan Garcia, MD

Jordan Garcia
Vanderbilt University Medical Center, United States
sy

shiayin F. yang, MD

Shiayin Yang
Vanderbilt University Medical Center
Nashville, Tennessee, United States

Senior Author(s)

Priyesh N. patel, MD

Priyesh Patel
Vanderbilt Univeristy Medical Center
Nashville, Tennessee, United States

Disclosure(s):

Alexander J. Barna, MD, MPH:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: The utility of electromyography (EMG)-guided botulinum toxin (BT) injections over standard anatomic-based injections for facial synkinesis remains unclear. This study evaluated differences in outcomes between EMG-guided and non–EMG-guided BT injections.

Methods: This longitudinal crossover study included patients with facial synkinesis treated at a tertiary facial nerve clinic. Patients were randomized to undergo either EMG-guided or non-EMG-guided BT injections, followed by the alternative option 3 months later. Patient-reported outcomes were assessed before and three weeks after each treatment using the Synkinesis Assessment Questionnaire (SAQ) and Facial Clinimetric Evaluation (FaCE) scale. Secondary outcomes included post-injection surveys evaluating pain, anxiety, and EMG preference. Objective physician-graded outcomes were assessed using pre- and post-treatment photographs independently graded by two physicians using the Sunnybrook Scale.

Results: 15 patients completed SAQ and FaCE assessments, 28 completed surveys, and 9 completed photographic evaluation. Patient-reported outcomes were similar between EMG-guided and non-EMG-guided injections, with comparable improvements in SAQ scores (ΔSAQ −10.08 vs −9.34, p=0.85) and FaCE scores (ΔFaCE 0.31 vs 1.88, p=0.73). Survey responses found no difference in pain (3.22 vs 3.30, p=0.76) or anxiety (1.89 vs 2.00, p=0.78) levels between EMG-guided and non-EMG-guided injections, with 50% of respondents preferring EMG guidance and 50% reporting no preference. There was no significant difference in overall ΔSunnybrook scores between EMG-guided and non-EMG-guided conditions (8.00 vs 10.11, p=0.55); however, EMG-guidance resulted in greater improvement in ΔSunnybrook synkinesis domain subscores (-4.06 vs -2.44, p=0.04).

Conclusions: EMG-guided BT injections yield similar patient-reported outcomes to non-EMG-guided injections. However, objective physician graded scores demonstrate greater improvement in synkinesis scores with EMG guidance, which may suggest a potential clinical advantage for targeted treatment.