Effect of Vibro-tactile Stimulation Intensity on Head Posture in Cervical Dystonia ((CD-VTS))

The Effects of Different Vibro-tactile Stimulation Intensities on Head Posture in Cervical Dystonia

The primary goal of this clinical trial is to examine the effects of cervical vibrotactile stimulation intensity on abnormal head posture in people with cervical dystonia. The main question is: Does higher vibration intensity correct head posture to a greater extent than lower vibration intensity? Researchers will compare the head posture of participants with cervical dystonia who receive different intensities of vibration to cervical muscles.

The secondary goal of this clinical trial is to examine the degree of proprioceptive impairment in cervical dystonia. Specifically, the study will assess proprioceptive impairment at the neck, wrist, and ankle joints, and seeks to determine whether the impairment improves with cervical vibrotactile stimulation.

Researchers will compare the proprioception testing results of these joints between cervical dystonia patients and age- and sex- matched healthy controls. Researchers will also compare the neck proprioception testing results of cervical dystonia patients before and after stimulation.

Participants will visit the lab once for three hours, where they will go through:

1. clinical questionnaires;
2. neck, wrist, and ankle proprioception testing,
3. vibrotactile stimulation where they sit and relax
4. neck proprioception testing

Study Overview

• Status: Recruiting
• Conditions: Cervical Dystonia
• Intervention / Treatment: Device: cervical vibrotactile stimulation

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jürgen Konczak, PhD; Phone Number: 612-624-4370; Email: jkonczak@umn.edu
• Study Contact Backup: Name: Jason Kang; Phone Number: 612-625-3313; Email: kang0463@umn.edu

Study Locations

• United States
  • Minnesota
    • Minneapolis, Minnesota, United States, 55455
      • Recruiting
      • Human Sensorimotor Control Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Confirmed diagnosis of adult-onset, isolated idiopathic cervical dystonia.

Exclusion Criteria:

History of other neurological diseases, including Parkinson's disease, essential tremor, dementia, etc.

History of peripheral nervous system disease that can impair proprioception. Deep brain stimulation implanted or denervation surgery. UBACC score lower than 15. Severe head tremors or facial muscle contractions. Regular intake of benzodiazepines or antidepressant medication.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cervical Dystonia Group; All participants with cervical dystonia will be in this group to receive the intervention. After answer three questionnaires (The Mini Mental State Examination, the Revised Toronto Western Spasmodic Torticollis Rating Scale and Psychiatric Screening Tool, Fahn, Tolosa, Marin Tremor Rating Scale), their neck, wrist, and ankle proprioception will be tested respectively. They they will go through the intervention of cervical vibrotactile stimulation. Lastly, their neck proprioception will be tested again.	Device: cervical vibrotactile stimulation; The intervention in this study is vibrotactile stimulation with 3 different intensities on 4 combinations of cervical muscles. The three intensity levels are 0.25mm, 0.64mm, and 1.48mm of movement range of the vibrator, when attached to the cervical area. The four muscle combinations (left and right SCM, left and right TRP, left SCM and TRP, right SCM and TRP) are selected as they were shown to be more effective than other combinations in a previous studies. The total number of bouts of stimulation is 12 (3 intensities * 4 muscle combinations). Each VTS application is 2 minutes long, resulting in total stimulation time of 24 minutes. There will be a 5-minute break of no-vibration between each application of vibration. During the intervention, the participant will remain seated and asked to not interfere voluntarily with dystonic muscle spasms. During breaks, they can adjust their head posture for their comfort. Extra breaks will be given if needed.
No Intervention: Healthy Controls; Healthy people age- and sex- matched with participants with cervical dystonia will be in this group. This group will only be tested on their neck, wrist, and ankle proprioception, to compare with the cervical dystonia group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Head Angle Index	The primary outcome measure is the head angle index, which quantifies how much a participant's head posture deviates from a neutral upright position. There are three degrees of freedom for the neck joint (axial rotation, lateral bending, and flexion/extension). For each participant, the degree(s) of freedom with abnormality will be identified at baseline. For any time period during the experiment, the mean absolute neck angle in each abnormal degree of freedom will be calculated and normalized by the typical maximal range of motion in healthy individuals. These normalized values will be averaged to yield the Head Angle Index.	As part of the one-time visit, this part will take 90 minutes.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Position Matching Error	The secondary outcome measure is absolute position matching error, which quantifies the position sense acuity of the participants in each joint. For each tested joint, they will be given a set of target position. The joint will be passively rotated to the target position, and back to the starting position. The participant will then try to reproduce the target position, based on their memory of the position. After repeating for 9 times, the absolute value of the differences between the matched position and the target position will be averaged to get the absolute position matching error.	As part of the one-time visit, this part will take 60 minutes.
the Toronto Western Spasmodic Torticollis Rating Scale Score	This three-part rating scale will evaluate the severity, disability and pain level of each CD participant. Each part results in a numerical score.	As part of this one-time visit, 10 minutes.
Fahn-Tolosa-Marin Clinical Rating Scale Score	Tremor severity level will be evaluated with this numerical score.	As part of a one-time visit, 10 minutes.

Collaborators and Investigators

• Sponsor: University of Minnesota
• Investigators: Principal Investigator: Jürgen Konczak, PhD, University of Minnesota

Study record dates

Study Major Dates

• Study Start (Actual): March 10, 2025
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): September 30, 2026

Study Registration Dates

• First Submitted: November 17, 2025
• First Submitted That Met QC Criteria: November 17, 2025
• First Posted (Actual): November 24, 2025

Study Record Updates

• Last Update Posted (Actual): June 10, 2026
• Last Update Submitted That Met QC Criteria: June 9, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: symptom control; non-invasive; proprioception; vibrotactile stimulation
• Additional Relevant MeSH Terms: Neurologic Manifestations; Dyskinesias; Dystonia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Torticollis
• Other Study ID Numbers: STUDY00024537

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No