University of Wisconsin–Madison
Dempsey Lab - Clinical and Research

Robert J. Dempsey Lab

Research Interests

Dr. Dempsey currently has multiple research projects with focus on cerebral ischemia and brain injury. Having been a Principal Investigator of grants from the National Institutes of Health, The Veterans Administration and the American Heart Association, Dr. Dempsey has developed a group of neurosurgeons and scientists dedicated to neurosurgical patient care.

  • The biochemistry and molecular biology of ischemic brain injury and traumatic brain injury.
  • Lipid changes and other factors in the formation of carotid artery atherosclerosis.
  • The stimulation and modification of adult stem/progenitor cells in brain after focal cerebral ischemia.
  • Acute management of subarachnoid hemorrhage.
  • Applied research in stroke, brain perfusion, subarachnoid hemorrhage and trauma.
  • The molecular Biology of Embolic Carotid diseases and its relationship to delayed cognitive impairment.

Several clinical studies are ongoing including studies to look at the pathophysiology of a recurrent stroke, the possibility of supplementing blood flow to the brain after carotid occlusion, the impact of sleep disordered breathing on cerebral vascular regulation, and the modification of interoperative cerebral ischemia with hypothermia. 


Uma Wesley, PhD,
Research Professor/Distinguished Scientist,

Dylan E. Nelson, BS
Research Specialist,

Current Clinical Research

Our clinical research area includes several projects focused on prevention of stroke risk factors in Native Americans.

One project implements and assesses an intense intervention to prevent stroke and vascular cognitive decline. This is a population-based health awareness program at the Oneida Nation which includes training of an Oneida Health Service coach working in partnership with the UW team. Through developing healthy living and stroke awareness events this study aims to provide education as to the severity of the problem as well as our standard therapies for lifestyle change and risk factor avoidance. This includes education of the healthy members of the Oneida Nation, including the children, as well as develop healthy lifestyles at the earliest ages to influence the elders to modify their risks.

Our second project wants to determine if health related social support interventions can improve traditional and novel risk factors for stroke and vascular cognitive impairment to the development of clinical deficits. For this study we are studying younger members of the Oneida nation which will receive education on how to modify their risk factors and will be assigned to work with a health wellness coach to developed programs that will address social support, diet, and exercise to modify traditional stroke risk factors and psychosocial stress.

For both studies, enrolled participants complete a medical and health assessment by a board certified physician, a full ultrasound of the carotid vessels, a cognitive battery with special emphasis on Native American tests, blood work to identify biomarkers for reducing or preventing stroke indicidence and wellness coaching.

Lastly, The Carotid Plaque Study is researching structural abnormalities in carotid plaque that can cause it to become unstable and embolize, possible causing silent strokes. Subjects in this study are recruited from a population of patients who are currently or will be scheduled to undergo carotid endarterectomy at the University of Wisconsin Hospital and Clinics due to the presence of high-grade atherosclerotic cervical internal carotid artery stenosis. Study procedure consist of a research-only MRI that detects if silent strokes have occurred, TCD and carotid ultrasound to map the plaque filled artery and determine what physical characteristics might cause plaque to rupture under the stress of pulsation, a neurocognitive assessment to measure pre-operative cognitive function and compare it to post-operative cognitive function, and blood collection to analyze RNA and protein expression profiles that can be used as biomarkers to identify the patients with a higher risk of plaque instability. 

If you’d like more information about ongoing clinical research studies please contact Stephanie Wilbrand PhD, at

Selected Publications

Cress, H. J., Mitchell, C. C., Wilbrand, S. M., Wesley, U. V., Morel Valdés, G. M., Hess, T., Varghese, T., Maybock, J., Metoxen, M., Riesenberg, A., Vandenberg, C., Blohowiak, C. J., Kennard, J., Danforth, D., & Dempsey, R. J. (2024). Methods in ‘Stroke Prevention in the Wisconsin Native American Population’. Neuroepidemiology, 10.1159/000536426. Advance online publication.

Kiernan, M. J., Al Mukaddim, R., Mitchell, C. C., Maybock, J., Wilbrand, S. M., Dempsey, R. J., & Varghese, T. (2024). Lumen segmentation using a Mask R-CNN in carotid arteries with stenotic atherosclerotic plaque. Ultrasonics137, 107193. 

Koueik, J., Wesley, U. V., & Dempsey, R. J. (2023). Pathophysiology, cellular and molecular mechanisms of large and small vessel diseases. Neurochemistry International164, 105499.

Wesley, U. V., Sutton, I., Clark, P. A., Cunningham, K., Larrain, C., Kuo, J. S., & Dempsey, R. J. (2022). Enhanced expression of pentraxin-3 in glioblastoma cells correlates with increased invasion and IL8-VEGF signaling axis. Brain research1776, 147752.

Mitchell, C., Gaitán, J. M., Pewowaruk, R. J., Gepner, A. D., Hess, T., Wilbrand, S. M., Dempsey, R. J., Dougherty, R. J., Cook, D. B., & Okonkwo, O. (2022). Transcranial Color-Coded Doppler Cerebral Hemodynamics Following Aerobic Exercise Training: Outcomes From a Pilot Randomized Clinical Trial. Journal for vascular ultrasound : JVU46(3), 110–117.

Wesley, U. V., Sutton, I. C., Cunningham, K., Jaeger, J. W., Phan, A. Q., Hatcher, J. F., & Dempsey, R. J. (2021). Galectin-3 protects against ischemic stroke by promoting neuro-angiogenesis via apoptosis inhibition and Akt/Caspase regulation. Journal of Cerebral Blood Flow & Metabolism41(4), 857-873.

Dempsey, R. J., & Buckley, N. A. (2020). Education-based solutions to the global burden of neurosurgical disease. World neurosurgery140, e1-e6.

Dempsey, R. J., & Bowman, K. (2020). The past, present, and future of neurosurgery’s role in stroke. Journal of Neurosurgery133(1), 260-266.

Meshram, N. H., Jackson, D., Mitchell, C. C., Wilbrand, S. M., Dempsey, R. J., Hermann, B. P., & Varghese, T. (2020). Study of the Relationship Between Ultrasound Strain Indices and Cognitive Decline for Vulnerable Carotid Plaque. Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference2020, 2088–2091.

Wesley, U. V., Bhute, V. J., Hatcher, J. F., Palecek, S. P., & Dempsey, R. J. (2019). Local and systemic metabolic alterations in brain, plasma, and liver of rats in response to aging and ischemic stroke, as detected by nuclear magnetic resonance (NMR) spectroscopy. Neurochemistry international127, 113–124.

Varghese, T., Meshram, N. H., Mitchell, C. C., Wilbrand, S. M., Hermann, B. P., & Dempsey, R. J. (2019). Lagrangian carotid strain imaging indices normalized to blood pressure for vulnerable plaque. Journal of clinical ultrasound : JCU47(8), 477–485.

Branch, C. L., Boop, F., Haglund, M. M., & Dempsey, R. J. (2018). Introduction. Neurosurgical opportunities in global health inequities. Neurosurgical focus45(4), E1.

Dempsey, R. J. (2018). Neurosurgery in the Developing World: Specialty Service and Global Health. World Neurosurgery112, 325-327.

Dempsey, R. J., Varghese, T., Jackson, D. C., Wang, X., Meshram, N. H., Mitchell, C. C., Hermann, B. P., Johnson, S. C., Berman, S. E., & Wilbrand, S. M. (2018). Carotid atherosclerotic plaque instability and cognition determined by ultrasound-measured plaque strain in asymptomatic patients with significant stenosis. Journal of neurosurgery128(1), 111–119.

Dempsey, R. J., Jackson, D. C., Wilbrand, S. M., Mitchell, C. C., Berman, S. E., Johnson, S. C., Meshram, N. H., Varghese, T., & Hermann, B. P. (2018). In Reply: The Preservation of Cognition 1 Year After Carotid Endarterectomy in Patients With Prior Cognitive Decline. Neurosurgery83(4), E181. 

Dempsey, R. J., Jackson, D. C., Wilbrand, S. M., Mitchell, C. C., Berman, S. E., Johnson, S. C., Meshram, N. H., Varghese, T., & Hermann, B. P. (2018). The Preservation of Cognition 1 Year After Carotid Endarterectomy in Patients With Prior Cognitive Decline. Neurosurgery82(3), 322–328.

Wesley, U. V., Hatcher, J. F., Ayvaci, E. R., Klemp, A., & Dempsey, R. J. (2017). Regulation of Dipeptidyl Peptidase IV in the Post-stroke Rat Brain and In Vitro Ischemia: Implications for Chemokine-Mediated Neural Progenitor Cell Migration and Angiogenesis. Molecular neurobiology54(7), 4973–4985.

Dempsey, K. E., Qureshi, M. M., Ondoma, S. M., & Dempsey, R. J. (2017). Effect of Geopolitical Forces on Neurosurgical Training in Sub-Saharan Africa. World neurosurgery101, 196–202. 

Mitchell, C. C., Wilbrand, S. M., Kundu, B., Steffel, C. N., Varghese, T., Meshram, N. H., Li, G., Cook, T. D., Salamat, M. S., & Dempsey, R. J. (2017). Transcranial Doppler and Microemboli Detection: Relationships to Symptomatic Status and Histopathology Findings. Ultrasound in medicine & biology43(9), 1861–1867. 

Mitchell, C. C., Stein, J. H., Cook, T. D., Salamat, S., Wang, X., Varghese, T., Jackson, D. C., Sandoval Garcia, C., Wilbrand, S. M., & Dempsey, R. J. (2017). Histopathologic Validation of Grayscale Carotid Plaque Characteristics Related to Plaque Vulnerability. Ultrasound in medicine & biology43(1), 129–137.

Jackson, D. C., Sandoval-Garcia, C., Rocque, B. G., Wilbrand, S. M., Mitchell, C. C., Hermann, B. P., & Dempsey, R. J. (2016). Cognitive deficits in symptomatic and asymptomatic carotid endarterectomy surgical candidates. Archives of Clinical Neuropsychology31(1), 1-7.

Berman, S. E., Wang, X., Mitchell, C. C., Kundu, B., Jackson, D. C., Wilbrand, S. M., Varghese, T., Hermann, B. P., Rowley, H. A., Johnson, S. C., & Dempsey, R. J. (2015). The relationship between carotid artery plaque stability and white matter ischemic injury. NeuroImage. Clinical9, 216–222.

Book Chapters

Haldeman D, Dempsey RJ. Intracranial Neoplasms in the Elderly. Accepted, Hazzard’s Textbook of Geriatrics and Gerontology. December 2014.

Bauer A, Dempsey R. The Pathophysiology of Cerebral Ischemia. Accepted, Neurovascular Surgery, 2nd Edition, Chapter III, pgs 203-215. October 2014.

McCormick, M, Dempsey, R, Varghese, T, Mitchell, C, Kliewer M. “Noninvasive Measurement of Pulsatile Carotid Plaque Deformation by Strain Tensor Ellipses: Possible Determinate of Symptomatology” Book of Proceedings (NX23) of the of ICCAD 2011 (October 23-26, 2011, Venice, Italy)

Yan Y, Vemuganti R, Dempsey RJ. Post-ischemic Neurogenesis and Brain Repair: Growth Factors and Cytokines. e-Book: Experimental Stroke. 2011, eISBN 978-1-60805-001-7