Mak, Jennifer
(2024)
Brain Mechanisms of Attention and Motor Deficits after Stroke.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Accomplishing most goals in daily life requires cooperation and coordination of the spatial attention networks to identify appropriate targets in the environment, and the motor network to plan and execute an action to the target. Strokes can disrupt these systems, as common deficits include spatial neglect and hemiparesis. Current stroke therapies leave many patients with lasting disabilities, and they are limited by our understanding of how these brain networks are affected by lesions and how they relate to subsequent impairments. This information may help us shape future rehabilitation strategies that target individual-specific deficits. In this thesis, we investigate the effects of stroke on spatial attention and motor planning
and employ novel technologies and techniques to examine these systems. In the first study, we investigate the changes in neural activation leading to spatial neglect in stroke patients. We built an objective measure of neglect using a combined augmented reality electroencephalography
(AR-EEG) system. This portable, adaptable device records neural correlates of a visual target detection task through EEG. In stroke patients with neglect, we found lateralized brain activation patterns spanning the frontal-parietal electrodes in response to contralesional targets,
particularly in alpha and beta frequency bands. We can also
detect neglect in individual patients with high accuracy using just their task-related EEGs. We find that asymmetric activation of the attention networks correlates with diminished spatial attention abilities. In the second study, we investigate the changes in non-primary motor area connectivity leading to component deficits of movement in subcortical stroke patients. We designed a planar reaching task in a robotic exoskeleton where transcranial
magnetic stimulation (TMS) was delivered to frontal and parietal locations during movement planning. Healthy controls’ kinematics were consistently perturbed by suprathreshold stimulation over the contralateral dorsal premotor cortex. By contrast, nearly every stroke patient
had a unique response to different stimulation parameters, revealing that even small subcortical strokes can elicit large-scale functional circuit-level changes between these preparatory areas and motor cortex, creating vastly different behavioral outcomes. Together, these studies provide insight into the variable mechanistic effects of stroke on brain activation and connectivity and are the first step to personalizing rehabilitation therapies.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
6 September 2024 |
| Date Type: |
Publication |
| Defense Date: |
16 July 2024 |
| Approval Date: |
6 September 2024 |
| Submission Date: |
22 July 2024 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
205 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Bioengineering |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
stroke, spatial neglect, hemiparesis, attention, motor function, rehabilitation, recovery, diagnosis, augmented reality, eeg, tms, brain stimulation |
| Date Deposited: |
06 Sep 2024 20:04 |
| Last Modified: |
06 Sep 2024 20:04 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/46722 |
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