Poster D101, Monday, March 26, 8:00-10:00 am, Exhibit Hall C
Neuroplastic and Neurovascular Contributions to Visual Recovery in Post-Stroke Cortical Blindness
Colleen Schneider1,2, Emily Prentiss2, Zoe Williams1, Bogachan Sahin1, Bradford Mahon1,2; 1University of Rochester School of Medicine and Dentistry, 2University of Rochester School of Arts Sciences and Engineering
The underlying mediators of post-stroke recovery remain poorly understood. Previous studies suggest that cortical reorganization and perilesional repair are mediators of post-stroke recovery; however, none of those studies have been able to provide a clear, generalizable association between those changes and recovery of function across patients. The present study investigates the relation between post-stroke visual recovery and i) perilesional neurovascular re-coupling, and ii) changes in retinotopic organization. Patients with visual field cuts secondary to stroke were studied longitudinally with 24-2 Humphrey perimetry and fMRI at 1 week, 1 month, 3 months, and 6 months post-stroke. Perimetry and functional MRI measures were brought into register with each other by dividing the visual field into 12 wedges that matched the area of the visual field stimulated by 12 checkerboard wedges during polar angle retinotopic mapping. The response of perilesional voxels to a full-field visual stimulus was significantly delayed compared to the contralesional hemisphere at 1 week but recovered by 3 months post-stroke in most patients. In addition, there was a shift in the preferred retinotopic bias of perilesional voxels towards the original blind field. Normalization of the delayed response of perilesional voxels accounted for visual recovery in patients who were initially blind in a hemifield and whose blind field resolved to one quadrant, while shifts in retinotopy toward wedge locations that were originally blind were associated with visual recovery in those wedge locations. We argue that the neurovascular and neuroplastic, in conjunction, explain variability in visual recovery across patients.
Topic Area: PERCEPTION & ACTION: Vision