367: A Case Report Describing the Use of the Butterfly as a Movement Marker of Dystonic Cervical Motions

Topic: Clinical Science
Subtopic: Pain category (ICD-11), Chronic primary musculoskeletal pain, Assessment and Measurement of Pain/Nociception, Digital Health Technologies , Treatment/management

Background and Aims: Idiopathic cervical dystonia (iCD) is characterized by sustained or intermittent neck movements caused by involuntary muscle contractions, resulting in abnormal movements and postures of head, neck, and/or shoulders. Currently, diagnostic approaches are based on clinical expert opinion and there is a lack of objective sensory motor tools to assess dystonic movements. The purpose of this case report is to describe the integration of the butterfly (FLY) assessment as a marker of dystonic movements.

Methods: A 22-year-old female presented for physical therapy treatment in an interdisciplinary pain clinic at an academic health institution. Physical therapy included neuromuscular re-education and motor control exercises over 6 months. Medical management included injection of botulinum toxin A for cervical dystonia with a total of 90 units distributed between her right trapezius, semispinalis capitus and sternocleidomastoid muscles. The FLY was assessed using the NeckCare System™ (NeckCare, Iceland) alongside worst pain severity (0 – 10 scale) at evaluation and discharge. The FLY provides temporal (on target ratio) and magnitude of error (deviation from target in degrees) during a cervical tracing task.

Results: At initial assessment, dystonic symptoms were constant with worst pain severity of 9/10, requiring frequent use of a soft cervical collar for symptomatic control. After 6 months of therapy, symptoms occurred only after sitting >20 minutes, with worst pain severity of 7/10. Furthermore, cervical soft collar use was discontinued. FLY on target ratio improved at easy, medium, and difficult levels from 6.7% to 27.7%, 6.0% to 14.6%, and 4.6% to 10.4%, respectively. In addition, the FLY average deviation from target improved at easy, medium, and difficulty levels from 12.6° to 2.9°, 11.2° to 5.4°, and 9.1° to 8.2°, respectively.

Conclusions: Currently, treatment outcomes for iCD rely primarily on self-report, and objective movement-based markers are limited. The FLY provides quantitative data demonstrating objective motor changes. Further, the FLY provides graphic outputs allowing patients to visually observe improvements. This may enhance patient engagement and perceived validation of treatment response. These findings suggest that the FLY is a promising tool for assessing movement quality in iCD. Further research is needed to evaluate its diagnostic utility and responsiveness to treatment.

References: 1. Albanese A et al. Isolated cervical dystonia: diagnosis and classification. Mov Disord. 2023;38:1367–78.
2. Rosales RL et al. Pain in cervical dystonia: mechanisms, assessment and treatment. Expert Rev Neurother. 2021;21:1125–34.
3. Kassaye SG et al. Physiotherapy for isolated cervical dystonia: systematic review and meta-analysis. BMC Neurol. 2024;24:53.
4. Caronni A et al. Smoothness of movement in idiopathic cervical dystonia. Sci Rep. 2022;12:5090.
5. Rodrigues FB et al. Botulinum toxin A for cervical dystonia. Cochrane Database Syst Rev. 2020;11:CD003633.

Presenting Author: Juan P. Gonzalez, DPT - University of Miami, Miller School of Medicine, APReCIAT Laboratory
Submitting Author: Juan Gonzalez

Senior Author: Marlon L. Wong, PhD - University of Miami, Miller School of Medicine, APReCIAT Laboratory

IASP 2026 Global Year theme of Neuropathic Pain: No

• Danielle B. Horn: MD - University of Miami, Miller School of Medicine
• Chelsea A. Miller: DPT, MSPH - University of Miami, Miller School of Medicine, APReCIAT Laboratory
• Ashley McCorry: DPT - PT Final Exam
• Jessica Bolanos: DPT - University of Miami, Miller School of Medicine, APReCIAT Laboratory
• Gabriel Gonzalez: DPT - University of Miami, Miller School of Medicine, APReCIAT Laboratory
• Maximillian O'Malley: DPT - University of Miami, Miller School of Medicine, APReCIAT Laboratory
• Annemay Lelis: DPT - University of Miami, Miller School of Medicine, APReCIAT Laboratory
• Richard Martinez: MS PSCH - University of Miami, Miller School of Medicine, APReCIAT Laboratory
• Jona M. Olafsdottir: PhD - NeckCare