Peripersonal Space Representation in Upper Limb Segmental Exclusion

Study of the Representation of Action Peripersonal Space in Participants With Unilateral Segmental Exclusion of the Upper Limb Compared to Asymptomatic Subjects

This study aims to evaluate the representation of action peripersonal space (PPS) in subjects suffering from unilateral segmental exclusion syndrome of the upper limb compared to healthy control subjects. Segmental exclusion is defined by non-use or under-use of a limb segment without central nervous system damage. The study hypothesizes that this syndrome leads to a modification (shrinkage) of the PPS representation. Participants will perform reachability judgments in a Virtual Reality (VR) environment.

Study Overview

• Status: Recruiting
• Conditions: Complex Regional Pain Syndrome (CRPS); Segmental Exclusion Syndrome; Upper Limb Neglect (Peripheral)
• Intervention / Treatment: Behavioral: Reachability Judgment Task in VR.

Detailed Description

Segmental exclusion syndrome often occurs after limb trauma and manifests as a neglect-like behavior of peripheral origin, sometimes associated with Complex Regional Pain Syndrome (CRPS). The study explores whether the lack of limb use affects the representation of peripersonal space (PPS)-the space immediately surrounding the body where interactions with objects occur.

The study is monocentric, observational, with a matched control group. Participants will undergo:

Clinical assessment (questionnaires on pain, anxiety, body perception, and kinesiophobia).

A Virtual Reality (VR) test (approx. 40 minutes). In VR, participants will judge whether a cylinder presented at different distances and angles is reachable without moving (Perceived Reachable Distance - DMA-p). This will be compared to their Real Reachable Distance (DMA-r).

The goal is to measure the error of judgment to assess PPS representation and check for correlations with body schema disturbances or functional impairment

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Amélie Touillet, MD; Phone Number: +33 3 83 52 98 80; Email: amelie.touillet@ugecam.assurance-maladie.fr
• Study Contact Backup: Name: Jonahtan Pierret, PhD; Phone Number: +33 3 83 52 67 61; Email: jonathan.pierret@ugecam.assurance-maladie.fr

Study Locations

• France
  • Nancy, France, 54000
    • Recruiting
    • Institut Régional de Médecine Physique et de Réadaptation (IRR), Centre Louis Pierquin.
    • Contact: Jonathan Pierret, PhD; Phone Number: +33 3 83 52 67 61; Email: jonathan.pierret@ugecam.assurance-maladie.fr

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

he study population consists of two groups recruited at the Institut Régional de Réadaptation (Centre Louis Pierquin, UGECAM Nord-Est) in Nancy, France.

Patients with Exclusion: Participants are selected from patients receiving routine care (full hospitalization or day hospital) at the center. They are identified based on a functional assessment ("Bilan 400 points") showing specific impairments related to unilateral upper limb exclusion evolving for more than 3 months.

Healthy Controls: Asymptomatic volunteers are recruited through the social or family network of the investigators and current participants, as well as via posters displayed in the UGECAM centers.

Description

Inclusion Criteria (patients):

• Age ≥ 18 years.
• Presenting unilateral exclusion symptom of the upper limb or part of the hand evolving for > 3 months.
• No contraindication to force work in daily activities.
• For patients with finger exclusion: at least 2 perturbed items related to exclusion on tests 3 and 4 of the "Bilan 400 points".
• Affiliated to a social security scheme.
• Able to understand simple orders.

Inclusion Criteria (Controls):

• Age ≥ 18 years.
• No history of upper limb impairment with sequelae.

Exclusion Criteria (All):

• Visual impairments.
• Central neurological pathology.
• Unstabilized psychiatric pathology.
• Communication or comprehension difficulties.
• Under legal protection or unable to consent.
• Pregnant or breastfeeding women.
• Cervical pathology contraindicating VR headset use.
• Epilepsy.
• Upper limb pathology unrelated to exclusion.
• Inability to stand for 40 minutes.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with Exclusion; Patients presenting with unilateral segmental exclusion of the upper limb or part of the hand evolving for more than 3 months.	Behavioral: Reachability Judgment Task in VR.; Participants wear an Oculus Quest 2 VR headset. They first perform a motor task to measure Real Reachable Distance (DMA-r). Then, they perform a perceptual task where they must judge, without moving, if a virtual object is reachable (DMA-p). The test evaluates different spatial planes (front, 45° right, 45° left) and heights (shoulder, navel).
Healthy Controls; symptomatic volunteers with no history of upper limb impairment with sequelae.	Behavioral: Reachability Judgment Task in VR.; Participants wear an Oculus Quest 2 VR headset. They first perform a motor task to measure Real Reachable Distance (DMA-r). Then, they perform a perceptual task where they must judge, without moving, if a virtual object is reachable (DMA-p). The test evaluates different spatial planes (front, 45° right, 45° left) and heights (shoulder, navel).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Judgment Error of Reachability	The Judgment Error of Reachability is a single composite metric calculated as: ((DMA-p - DMA-r) / DMA-r) × 100, expressed as a percentage (%). Both DMA-p (Perceived Maximum Reachable Distance) and DMA-r (Real Maximum Reachable Distance) are measured in centimeters, and their ratio yields a single dimensionless percentage score.	Day 1 (During the 40-minute VR assessment)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body Perception Disturbance Score	Assessed using the Bath CRPS Body Perception Disturbance Scale (French version). Scores range from 0 to 57, with higher scores indicating greater disturbance.	Day 1 (Before VR task)
Anxiety and Depression Score (HAD)	Hospital Anxiety and Depression Scale. Scores range from 0 to 21 for each dimension (Anxiety and Depression).	Day 1
Kinesiophobia Score (Tampa Scale)	Tampa Scale for Kinesiophobia (TSK). Assesses fear of movement. Scores range to 68; >40 indicates significant kinesiophobia.	Day 1
Pain Catastrophizing Score (PCS)	Pain Catastrophizing Scale. Scores range from 0 to 52.	Day 1
Functional Impairment Score (400-Point Hand Assessment)	Evaluated using the 400-Point Hand Assessment, which measures functional hand use. The score ranges from 0 to 400, where higher scores indicate better functional performance (better outcome).	Day 1

Collaborators and Investigators

• Sponsor: Union de Gestion des Etablissements des Caisses d'Assurance Maladie - Nord Est

Study record dates

Study Major Dates

• Study Start (Actual): December 4, 2025
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): January 1, 2028

Study Registration Dates

• First Submitted: January 8, 2026
• First Submitted That Met QC Criteria: January 8, 2026
• First Posted (Actual): January 16, 2026

Study Record Updates

• Last Update Posted (Actual): March 16, 2026
• Last Update Submitted That Met QC Criteria: March 12, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Virtual Reality; Body Schema; Peripersonal Space; Reachability Judgment
• Additional Relevant MeSH Terms: Nervous System Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Autonomic Nervous System Diseases; Behavior; Spatial Behavior; Complex Regional Pain Syndromes; Personal Space
• Other Study ID Numbers: IRR-CLP-2023-3; 2025-A02189-40 (Other Identifier: ID-RCB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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