Eye Movements and Visuo-spatial Perception

• ClinicalTrials.gov Identifier: NCT03112408
• Recruitment Status: Completed
• First Posted: April 13, 2017
• Last Update Posted: April 21, 2022
• Sponsor: Hospices Civils de Lyon
• Information provided by (Responsible Party): Hospices Civils de Lyon

Tracking Information

• First Submitted Date: March 29, 2017
• First Posted Date: April 13, 2017
• Last Update Posted Date: April 21, 2022
• Actual Study Start Date: September 26, 2018
• Actual Primary Completion Date: October 2, 2020 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (submitted: April 7, 2017)

Saccadic adaptation efficiency [ Time Frame: At time of each experimental session, up to 2 months, since first experimental visit until last visit ]

〖Adaptation〗_rate= (〖Amplitude 〗_post-〖Amplitude 〗_pre)/〖Amplitude 〗_pre

• Original Primary Outcome Measures: Same as current

Current Secondary Outcome Measures (submitted: April 7, 2017)

• Evolution of localization-task performances [ Time Frame: At time of each experimental session, up to 2 months, since first experimental visit until last visit ]
  〖Improvement〗_performances= (〖Mislocalization 〗_post-〖Mislocalization 〗_pre)/〖Mislocalization 〗_pre
• Evolution of attentional performances assessed by neuropsychological tests of neglect [ Time Frame: At time of each experimental session, up to 2 months, since first experimental visit until last visit ]
  〖Improvement〗_performances= (〖Score 〗_post-〖Score〗_pre)/〖Score〗_pre

• Original Secondary Outcome Measures: Same as current
• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Eye Movements and Visuo-spatial Perception
• Official Title: Coupling Between Adaptation of Saccadic Eye Movements and Visuo-spatial Perception and Attention Processes: a Behavioural Study in Humans.
• Brief Summary: This research aims to highlight the key roles of the cerebellar and cortical fronto-parietal networks in the coupling of eye movements with visual perception and visuo-spatial attention.

Detailed Description

The first axe of this research focuses on the role of the cerebellum which has a major contribution to sensorimotor adaptation and more precisely in saccadic adaptation but the nature of this contribution is still debated. A classical assumption stipulates cerebellum has an exclusive action on saccadic burst generator in the brainstem whereas recent data increasingly support the view that cerebellum could also modulates cerebral cortex through a cerebello-thalamo-cortical pathway. On the other hand, several studies have shown that modification of saccade amplitude by saccadic adaptation leads to a distortion of the visual localization of briefly flashed spatial probes but no study to date has tested, the contribution of the cerebellum in these adaptation-induced mislocalizations. The main objective of this axe is to define the role of the cerebellum not only in saccadic adaptation, but also in mislocalizations which occur after adaptation. Moreover, in testing this assumption, arguments in favour -or in disfavor- of the action of the cerebellum on cortical stages dedicated to visuo-spatial perceptual processing will be provided. Besides, variability of cerebellar lesion (or cerebellar dysfunction) location in patients can lead to different pattern in saccadic adaptation and localization task performances. Identification of dissociations between these two abilities in some patients will define more precisely the role of the cerebellum in the coupling between saccadic adaptation and visuo spatial perception as an oculomotor plasticity territory and / or as a territory underlying the error signal coding generating this type of plasticity.

This second axe of this research aims to apply basic findings in healthy subject on the coupling between oculomotor plasticity and spatial attention to patients with parietal lesion, in order to evaluate a rehabilitation procedure for neglect patients. Habchi and colleagues showed that the adaptation of reactive saccades in the left hemifield has a boosting effect on attentional performance in the same hemifield. The coupling between these two mechanisms highlighted in healthy subjects can be used as fundamentals in the elaboration of a rehabilitation procedure for attentional disorders in the neglect syndrome. This syndrome is mainly observed after cerebral lesions in the right hemisphere, and is characterized by very disabling cognitive disorders such as an alteration of the spatial representation of left hemi-space and/or left hemi-body. stimulation of sensorimotor plasticity thanks to prismatic adaptation could be used as a rehabilitation procedure for this syndrome. Being another efficient way to stimulate sensorimotor plasticity, the equip believe that saccadic adaptation can also be used as a rehabilitation procedure for neglect patients. Moreover, due to its tight coupling with visual attention, the benefits of saccadic adaptation could be even stronger and longer lasting than the visuo-manual plasticity induced by prismatic adaptation.

• Study Type: Interventional
• Study Phase: Not Applicable
• Study Design: Allocation: Randomized; Intervention Model: Factorial Assignment; Masking: Single (Participant); Primary Purpose: Basic Science
• Condition: Cerebellum Disease

Intervention

• Behavioral: Forward adaptation of reactive saccades
  Protocol of reactive saccade where the target is displaced in the same direction as the saccade in order to induce an adaptive increase of saccade amplitude ('forward adaptation')
• Behavioral: Backward adaptation of reactive saccades
  Protocol of reactive saccade where the target is displaced in a direction opposite to the saccade in order to induce an adaptive decrease of saccade amplitude ('backward adaptation')
• Behavioral: Execution of reactive saccades
  Control protocol of reactive saccade with no displacement of the saccadic target (controlling for non specific factors possibly involved in forward and backward adaptation conditions)
• Behavioral: Generation of reactive saccades
  Control protocol of reactive saccade with no displacement of the saccadic target (controlling for non specific factors possibly involved in adaptation condition)

Study Arms

• Experimental: FORWARD (Axe 1)
  Intervention: Behavioral: Forward adaptation of reactive saccades
• Experimental: BACKWARD (Axe 1)
  Intervention: Behavioral: Backward adaptation of reactive saccades
• Experimental: CONTROL (Axe 1)
  Intervention: Behavioral: Execution of reactive saccades
• Experimental: ADAPTATION (Axe 2)
  Intervention: Behavioral: Backward adaptation of reactive saccades
• Experimental: CONTROL (Axe 2)
  Intervention: Behavioral: Generation of reactive saccades

• Publications *: Not Provided

Recruitment Information

• Recruitment Status: Completed
• Actual Enrollment (submitted: April 20, 2022): 24
• Original Estimated Enrollment (submitted: April 7, 2017): 75
• Actual Study Completion Date: October 2, 2020
• Actual Primary Completion Date: October 2, 2020 (Final data collection date for primary outcome measure)

Eligibility Criteria

Inclusion Criteria:

• Age : from 18 to 80 ans included
• Visual acuity monocularly at distance and near corrected : > 5/10
• Possible understanding of experimental guidelines
• Possible respect for sustained seated position
• Subject covered by social security
• Agreement of the subject

Inclusion Criteria, specific to Axe 1:

• Cerebellar patients - Cerebellar degenerative disease (group A) or stroke (group B, délai depuis l'AVC : delay from the stroke : at least 1 month)

  • Scanner or MRI showing diffuse atrophy (group A) or focal cerebellar lesion (group B)

• Healthy subjects

  • Absence of known ophtalmological or neurological pathology

Inclusion Criteria, specific to Axe 2:

• Stroke patients - ischemic or hemorrhagic stroke

  • Encephalic MRI or CT scan showing an unique lesion
  • Minimal delay of one year after the stroke

Exclusion Criteria:

• Visual acuity monocularly < 5/10
• Language disorder restricting oral and reading comprehension of the study
• Severe disability limiting the maintenance of sitting position and concentration capacities for a period of 30 minutes consecutive
• Poor French language skills
• Non-stabilized medical condition
• Psychotropic medication intake
• Pregnant and / or nursing women
• Subject under guardianship or curatorship
• Subject frequently in healthcare or social care for purposes other than research
• Subject deprived of liberty by a judicial or administrative decision

Exclusion Criteria, specific to Axe 1:

• Cerebellar patients

- Disorders prohibiting the correct performance of the task (tremor, ocular instability)

Exclusion Criteria, specific to Axe 2:

• Stroke patients

• Hemianopsia homonima lateral
• Neurological degenerative disease

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 18 Years to 80 Years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: France

Administrative Information

• NCT Number: NCT03112408
• Other Study ID Numbers: 69HCL17_0109; 2017-A00942-51 ( Other Identifier: ID-RCB )
• Has Data Monitoring Committee: No

U.S. FDA-regulated Product

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

IPD Sharing Statement

• Plan to Share IPD: No

• Current Responsible Party: Hospices Civils de Lyon
• Original Responsible Party: Same as current
• Current Study Sponsor: Hospices Civils de Lyon
• Original Study Sponsor: Same as current
• Collaborators: Not Provided

Investigators

• Principal Investigator: Caroline Tilikete, MD; Hospices Civils de Lyon

• PRS Account: Hospices Civils de Lyon
• Verification Date: April 2022