Peripersonal Space Representation in Upper Limb Segmental Exclusion

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

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.