Rehabilitation For Acquired Visual Field Defects: Development Of A Bottom-Up Approach

Summary

Cortical Visual Field Defects (CFVD) are common after acquired brain injury. They often cause problems with reading and visual exploration which impact on patients' quality of life. Apart from the substitutive method that uses prisms directly placed on glasses, two main rehabilitative methods have been explored previously: one restorative and one compensatory. The most effective methods seem to be based on compensatory training paradigms that target eye movements. They rely on voluntary mass-practice that induces changes in exploratory saccadic behaviour, particularly into the blind hemifield. Previous studies using this method have shown changes in visual scanning patterns but with only a marginal profit in terms of functional benefit.

In the present study, the investigators developed a new approach to the compensatory visual field training based solely on a bottom-up mechanism. It does not require the patients' ability to voluntarily maintain attention oriented to the affected field, which may be difficult for brain-damaged patients. As previously reported in other pathological contexts (e.g. use of prism adaptation or sensory stimulation in neglect patients), bypassing voluntary and conscious implication of the patient can produce improvements by a more automatic process.

The investigators hypotheses are: 1) that a novel ramp-step search paradigm can be used by hemianopic patients to automatically improve targeted eye movements into their blind visual field; and 2) that this will lead to behavioural improvements on ecologically valid tests of visual search.

Conditions

• Acquired Visual Field Defects

Interventions

OTHER

Treatment A

The computer-based training task consists of a novel ramp-step search paradigm with a stimulus traversing the screen from left to right or right to left. Subjects are asked to pursue the stimulus (ramp phase) and then saccade to find its location when it suddenly jumps (step phase). The stimulus is an open spinning circle. At the end of each movement, the gap can be located at the top or at the bottom, and patients are asked to indicate this location by pushing the response button as quickly as possible. The starting point will alternate between left and right. The training task includes 3 sessions with 100 movements each. Reaction Times and errors will be monitored online to ensure that the patient performs the task correctly. Each treatment phase has the same pattern: * two visits in pre-tests evaluation (V1 and V2), * one visit to perform treatment (A or B) and to assess immediate and 2h post-effects (V3), * two visits after treatment (V4 at one week and V5 at one month).

OTHER

Treatment B

Placebo treatment using the same computer-based training task, but including only the ramp phase. Each treatment phase has the same pattern: * two visits in pre-tests evaluation (V1 and V2), * one visit to perform treatment (A or B) and to assess immediate and 2h post-effects (V3), * two visits after treatment (V4 at one week and V5 at one month).

Sponsors & Collaborators

• Hospices Civils de Lyon

  lead OTHER

Principal Investigators

• Sophie Jacquin-Courtois, MD, PhD · Service de Médecine Physique et de Réadaptation

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2010-11-29

Primary Completion

2018-06-13

Completion

2018-06-13

Countries

• France

Study Locations