Virtual Reality in Functional Movement Disorder (VR-FMD)

The Effect of Virtual Hand Movements on Functional Tremor - a Pilot Study

This study investigates the effect of virtual reality (VR) motor tasks on functional movement disorders.

Study Overview

• Status: Recruiting
• Conditions: Functional Movement Disorder
• Intervention / Treatment: Diagnostic test: Virtual reality motor task

Detailed Description

The investigators want to investigate how different display modes of virtual hands and the experimental manipulation of the visual representation of virtual hand movements affect (1) the performance of the hand movements (2) the tremor and (3) the subjective perception of the tremor.

There are three groups: Patients with functional tremor (FT), patients with essential tremor (ET) and healthy controls (HC). The study is carried out on one or two consecutive days. The first appointment is only made for patients with ET and FT and is used for the neurological examination and to assess the severity of the tremor. It takes place at the Outpatient Clinic for Movement Disorders at the University Clinic for Neurology in Graz and lasts a maximum of 30 minutes. The second appointment is at the Institute of Psychology at the University of Graz and requires the active participation of the respondent for 2.5 hours. Subjects are asked not to take any tremor-influencing medication on the day of the examination. HC will only attend the appointment at the Institute of Psychology.

First appointment:

• Clinical Global Impression - Severity Scale (CGI-S): 5-point Likert scale, clinicians assess the severity of the condition
• Patient Global Impression of Severity (PGI-S): 5-point Likert scale, patients assess the severity of the condition
• Fahn Tolosa Marin Tremor Rating Scale (FTM): assesses the tremor severity
• Simplified Version of the Functional Movement Disorders Rating Scale (S-FMDRS): assesses the severity of the functional tremor

Second appointment:

1. Questionnaires:

   • Simulator Sickness Questionnaire (SSQ): 4-point Likert scale, assesses nausea, oculomotor and visual disturbances, disorientation (2 timepoints: before and after VR tasks)
   • Edinburgh Handedness Inventory (EDI)
   • Questionnaire about sociodemographic data
   • Technology Usage Inventory (TUI): 7-point Likert scale, acceptance and use of technologies
   • Igroup Presence Questionnaire (IPQ): sense of presence in the VR
2. electroencephalogram (EEG) and surface-Electromyography (surface-EMG) of forearm muscles: run synchronously with the examinations

3. VR-tasks: all tasks are carried out in randomized order

   1. 3x3 matrix: individual fields light up in random order, participants are instructed to touch the fields in the given sequence as quickly as possible. 30 repetitions with a realistic VR-hand model and 30 repetitions with an abstract VR-hand model.
   2. 3x3 matrix: same task as (a) but after each repetition, participants must touch a field labeled "next" to continue the task. 30 repetitions.
   3. apple in a box: a virtual apple is to be placed in a virtual box using the hand with the weaker tremor, while the other hand is left resting on the table. 30 repetitions.
   4. apple in a box: same task as (c) but the resting hand is not visible. 30 repetitions.

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Daniela Kern, MD; Phone Number: 004331638516051; Email: daniela.eibl@medunigraz.at
• Study Contact Backup: Name: Petra Schwingenschuh, MD; Phone Number: 004331638583379; Email: petra.schwingenschuh@medunigraz.at

Study Locations

• Austria
  • Graz, Austria, 8010
    • Recruiting
    • Medical University of Graz, Department of Neurology
    • Contact: Daniela Kern, MD; Phone Number: +4331638516051; Email: daniela.eibl@medunigraz.at

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• diagnosis of functional tremor (FT) or essential tremor (ET) or healthy control persons
• In patients with FT and ET: presence of a constant or intermittent tremor during the neurological examination

Exclusion Criteria:

• unclear tremor syndrome
• essential tremor plus (ET plus)
• conditions that interfere with EEG diagnostic (skin conditions, skin infections, wounds)
• reflex epilepsy
• cervical degeneration or chronic pain syndrome of the cervical spine
• severe somatic illness
• previous cerebral or head surgery
• implanted pacemaker or deep brain stimulation
• persons who are unable to consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Functional Movement Disorder	Diagnostic test: Virtual reality motor task; After a short practice task, participants perform motor tasks in a virtual reality environment. Reaction time is used to assess task performance.
Experimental: Essential Tremor	Diagnostic test: Virtual reality motor task; After a short practice task, participants perform motor tasks in a virtual reality environment. Reaction time is used to assess task performance.
Experimental: Healthy Control	Diagnostic test: Virtual reality motor task; After a short practice task, participants perform motor tasks in a virtual reality environment. Reaction time is used to assess task performance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Task performance	Reaction time in processing the VR task, measured in seconds	4 measurement points: abstract hand model without time pressure, abstract hand model with time pressure, realistic hand model without time pressure, realistic hand model with time pressure. Approximately 2.5 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tremor duration	Duration of tremor during the motor task, expressed as % of movement time (only in FT and ET)	5 measurement points: tasks a, b, c, d; Approximately 2.5 hours
EEG	Changes in mu and beta event-related (de)synchronizations between motor tasks and right and left hemispheres	10 measurement points: resting state before each motor task and during each motor task; Approximately 2.5 hours
Subjective tremor severity on a visual analogue scale (VAS)	Subjective tremor severity measured by a visual analogue scale (VAS) from 0 to 10 points, with higher scores indicating greater tremor severity	6 measurement points: before and after each task; Approximately 2.5 hours
VR acceptance	Technology Usage Inventory (TUI): from 29 to 203 points, with higher scores indicating greater acceptance of technologies	2 measurement points: before and after the VR examination, Approximately 2.5 hours

Collaborators and Investigators

• Sponsor: Medical University of Graz
• Investigators: Principal Investigator: Petra Schwingenschuh, MD, Medical University of Graz

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2024
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): March 30, 2026

Study Registration Dates

• First Submitted: March 28, 2024
• First Submitted That Met QC Criteria: April 29, 2024
• First Posted (Actual): May 1, 2024

Study Record Updates

• Last Update Posted (Estimated): September 29, 2025
• Last Update Submitted That Met QC Criteria: September 23, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Virtual Reality; Tremor; Functional neurological disorder
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Dyskinesias; Somatoform Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Tremor; Conversion Disorder
• Other Study ID Numbers: 36-115 ex 23/24

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
• product manufactured in and exported from the U.S.: No