Identifying residual visual brain networks after stroke
Supervisors : Denis Schluppeck, Richard Bowtell, Susan Francis, Rob Dineen,
Research Proposal
Every year in the UK about 150,000 people have a stroke – ‘the brain equivalent of a heart attack’. One third of stroke survivors are left with sight loss on one side of the visible world. This has a serious impact on their daily
function, significantly increases the likelihood of trips and falls, impairs reading ability, and makes driving impossible.
Sight loss after stroke is caused by damage to parts of the brain that engender visual perception. Permanent damage to the “primary” visual brain pathway is the most common and debilitating effect of stroke on visual function, leading to a loss of conscious visual perception on one side of the visible world – so called “cortical blindness”.
Aim of the study
Our aim is to identify residual visual brain networks that survived the stroke and – ultimately – to retrain them to detect and discriminate visual input in the cortically blind visual field.
Technical challenges
To estimate the capacity of brain pathways to generate vision in the cortically blind visual field, we will use magnetic resonance brain imaging (MRI) to measure the detailed structure and responsiveness of spared cortex in the occipital lobe. We will measure visual cortical responses to stimuli presented at sequential points in the visual field to reconstruct the representation of visual space in different cortical areas within the visual brain.
However, stroke survivors often present with tremors and other abnormal control of movements. In addition, they are less likely to tolerate staying in an MR scanner for prolonged periods of time.
This project will explore the use of accelerated imaging techniques and (near) real-time corrections for motion in the scanner to improve data quality and speed up acquisition time for anatomical and functional (BOLD) sequences.