Clinical trial NCT06636994: Anatomical and Functional Predictions of Blindsight Capabilities in Patients With Lateral Hemianopsia
Official title: Anatomical and Functional Predictions of Blindsight Capabilities in Post-Stroke Patients With Homonymous Hemianopia (PRE-SIGHT)
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Homonymous Hemianopia
Stroke
Cortical Blindness
Hemianopia
Lead sponsor: Fondation Ophtalmologique Adolphe de Rothschild
Sponsor class: NETWORK
First posted: 2024-10-15
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
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

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.


Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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)

Primary outcomes:
measure: Description of resting-state functional MRI measurement of the degree of Resting State Functional Connectivity (RSFC) between left and right hemisphere regions.
timeFrame: DAY 0
Secondary outcomes:
measure: Correlation between inter-hemispheric functional connectivity and blindsight performance
timeFrame: DAY 0
measure: Density and intensity of visual and attentional default networks in each type of blindsight
timeFrame: DAY 0
measure: Blindsight performance according to the laterality of the lesion (left or right hemisphere)
timeFrame: DAY 0
measure: Correlation between the level of inter-hemispheric functional connectivity and blindsight performance
timeFrame: DAY 0
measure: Correlation between visual default network density and intensity and blindsight performance
timeFrame: DAY 0
measure: Correlation between lesion volume and blindsight performance
timeFrame: DAY 0
Other outcomes:
Locations:
city: Paris
country: France
facility: Hopital Fondation Adolphe de Rothschild
Study officials:
affiliation: Integrative Neuroscience and Cognition Center
name: Clémentine GARRIC
role: PRINCIPAL_INVESTIGATOR
References: