Anatomical and Functional Predictions of Blindsight Capabilities in Patients With Lateral Hemianopsia

NCT06636994 | Active Not Recruiting

• 1 other identifier: CGC_2024_3
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Homonymous lateral hemianopia (HLH) is characterized by loss of vision in half the visual field, and is the most common neurovisual disorder following stroke. Numerous behavioral and neuroanatomical studies have focused on the phenomenon of blindsight, corresponding to patients' unconscious residual visual capacities in the blind hemifield. Cohort studies of patients have highlighted different types of blindsight, and a low occurrence of the phenomenon initially described: (1) type 1 blindsight (≈12%), unconscious visual abilities; (2) type 2 blindsight, visual abilities associated with sensations in the blind field (≈18%); (3) blindsense, sensations in the blind field without visual abilities (≈30%); and (4) no blindsight (≈40%). The heterogeneity of these blindsight abilities in the HLH population is closely related to patients' neuroanatomical and functional profiles. In particular, resting-state functional imaging (r-fMRI) and default mode network analysis have highlighted a significant correlation between the degree of inter-hemispheric connection (between the healthy and injured hemispheres) and the rate of spontaneous visual field recovery. To our knowledge, this degree of functional connectivity has not yet been studied in relation to blindsight abilities. However, this functional MRI measurement tool represents a potential predictive factor for patients' residual performance in their blindsight field, in order to assess the level of visuo-cognitive impairment and, ultimately, to adapt care.

Conditions

Homonymous Hemianopia; Stroke; Cortical Blindness; Hemianopia

Outcome Measures

Primary Outcomes (1)

• Description of resting-state functional MRI measurement of the degree of Resting State Functional Connectivity (RSFC) between left and right hemisphere regions.

  Comparison of the degree of inter-hemispheric Resting State Functional Connectivity between the four patient groups: absence of blindsight, type I blindsight, type II blindsight and blindsense.

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Secondary Outcomes (6)

• Correlation between inter-hemispheric functional connectivity and blindsight performance

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• Density and intensity of visual and attentional default networks in each type of blindsight

  DAY 0

• Blindsight performance according to the laterality of the lesion (left or right hemisphere)

  DAY 0

• Correlation between the level of inter-hemispheric functional connectivity and blindsight performance

  DAY 0

• Correlation between visual default network density and intensity and blindsight performance

  DAY 0

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients over 18 years of age with homonymous lateral hemianopia undergoing cerebral MRI for follow-up and rehabilitation following stroke

You may qualify if:

• Subjects aged 18 and over
• with homonymous visual field amputation sequelae of a retrochiasmatic lesion of vascular origin (stroke), including the occipital region (primary visual cortex, optic radiations, associated occipital areas)
• Requires follow-up brain MRI as part of treatment
• Able to perform experimental tasks on computer
• Express consent to participate in the study
• Member or beneficiary of a social security scheme

You may not qualify if:

• Severe neuropsychological disorders (language, memory, attention, vigilance, reasoning)
• Severe ophthalmological disorders or visual acuity below 3/10 prior to stroke
• Progressive ophthalmological disorders (cataract or glaucoma) likely to bias measurements
• Major psychiatric or behavioral disorders making care impossible
• Patient benefiting from a legal protection measure
• Pregnant or breast-feeding women (declarative information)

Sponsors & Collaborators

• Fondation Ophtalmologique Adolphe de Rothschild: lead

Study Sites (1)

Hopital Fondation Adolphe de Rothschild

Paris, 75019, France

Location

MeSH Terms

Conditions

Hemianopsia; Stroke; Blindness, Cortical

Condition Hierarchy (Ancestors)

Vision Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Blindness; Eye Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases

Study Officials

• Clémentine GARRIC

  Integrative Neuroscience and Cognition Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: NETWORK
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 9, 2024
• First Posted: October 15, 2024
• Study Start: November 21, 2024
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2029
• Last Updated: April 1, 2025

Record last verified: 2025-03

Locations

FR (1)