Notice and Invitation
Oral Defense of Doctoral Proposal
Department of Bioengineering
The Volgenau School of Engineering, George Mason University


Binal Brahmbhatt

Bachelor of Science, Biomedical Engineering, Gujarat University, 2009
Master of Science, Biomedical Engineering, Gujarat Technological University, 2012





Assessment of hemodynamic mechanism responsible for cognitive and mobility impairments in Asymptomatic Carotid Stenosis population with non-invasive imaging methods



Tuesday, December 7, 2021, 2pm-4pm
Peterson 4115

or via Zoom here<https://gmu.zoom.us/j/99212728482?pwd=Y1hyM0cwQnpzUi9SNURnOGx4dGFWZz09>
Meeting ID: 992 1272 8482
Passcode: 550373

All are invited to attend.

Committee
Dr. Siddhartha Sikdar, Director
Dr. Parag Chitnis, Chair
Dr. Kirk Beach
Dr. James Thompson


Abstract

Asymptomatic Carotid Artery Stenosis (ACAS) affects 12 percent of men and over 7 percent of women, older than 70 years of age. Carotid artery stenosis is one of the major risk factors for stroke and is common in patients with vascular risk factors or coexistent pathology of coronary or peripheral arteries. Patients with stenosis (50 % carotid artery diameter reduction) and no history of stroke or transient ischemic attack are considered ACAS subjects. The annual risk of stroke is 2-5% in ACAS population. Currently the  dilemma about the selection of a surgical treatment and its effectiveness for ACAS subjects makes it imperative to improve treatment decisions for ACAS, as not all future strokes will originate from the stenosed internal carotid artery.

This first part of dissertation investigates markers for identifying subgroup of ACAS subjects with pressure reducing stenosis with various non-invasive modalities like TCD , Doppler Ultrasound and MR angiography. This will help to better classify the ACAS patient's need for carotid  endarterectomy   and that would eventually reduce overall number of surgical procedures. We utilize MR angiography data to understand the status of circle of will is and correlate it with cognitive scores of ACAS subjects to show impact of hypo-perfusion on cognitive decline. In second part we investigated the impact of exercise intervention during several cognitive and mobility tasks on cerebral hemodynamics in ACAS subjects with fNIRS modality. FNIRS is a noninvasive optical imaging technique that uses near infrared light to assess brain activity based on the principle of neurovascular coupling. fNIRS basically measures changes in light absorption in a volume of tissue, which is the reflection of local neuronal activity. The third part of dissertation investigates the impact of head movements on fNIRS signals as we propose that the fNIRS measured the deoxygenated blood in venous compartment.



Carol McHugh
Academic Program Assistant
Department of Bioengineering
3100 Peterson Family Health Services Hall
703-993-5846