OUR TEAM

Stanford Neurosurgical Artificial Intelligence and Machine Learning Laboratory


Anand Veeravagu, MD
Associate Professor of Neurosurgery
Director, Minimally Invasive Neurospine Surgery

Dr. Anand Veeravagu is Associate Professor of Neurosurgery and Associate Professor of Orthopedic Surgery, by courtesy, and Director of Minimally Invasive NeuroSpine Surgery here at Stanford. Dr. Veeravagu is board certified and is focused on advancing minimally invasive surgical techniques for diseases of the spine and cares for patients with a wide range of spinal disorders. Dr. Veeravagu is the Team Neurosurgeon for the San Francisco 49ers Football Team.


Allen Ho, MD
Neurosurgery PGY-5

Allen was born and raised in Irvine, California. He completed his undergraduate training at University of California, San Diego as part of the combined-degree Medical Scholars Program with a major in Economics. He then left California to attend Harvard Medical School where he earned his MD in 2014. His research interests include expanding indications for deep brain stimulation and neuromodulation, technology-driven minimally-invasive approaches to cranial and spinal neurosurgery, and quality improvement initiatives within spine surgery neurosurgery. In the Veeravagu Lab, Allen is utilizing advanced robotic technology to improve the efficiency and efficacy of minimally invasive spine surgery and leveraging large national databases to address quality improvement and cost effectiveness in spine surgery.


Arjun Pendharkar, MD
Neurosurgery PGY-5

Arjun was born and raised in the Bay Area. He graduated from Cal Poly San Luis Obispo with a degree in Microbiology. At Cal Poly, Arjun worked in the lab of Dr. Michael Black where he studied Celiac Disease—cloning a novel strain of prophylactic Lactobacillus bacteria to cleave immunogenic gliadin peptides in the small intestine. Prior to attending medical school at Georgetown University, Arjun spent a year in the Department of Neurosurgery at Stanford in the labs of Dr. Raphael Guzman and Dr. Gary Steinberg studying intravascular neural stem cell therapy for stroke—specifically elucidating the difference between intra-arterial and intravenous injection. Arjun is currently a PGY5 resident, pursuing a two year enfolded postdoctoral fellowship in the Steinberg lab applying optogenetic tools towards studying mechanisms of injury in stroke. He was awarded the NREF/AANS research fellowship as well as the NIH R25 grant in support of his basic science research. Arjun’s clinical interests include evidence based outcomes research —  using national and multi-institutional databases to study cost, outcomes and practice variations within neurosurgery.


Zachary Medress, MD
Neurosurgery PGY-4

Dr. Medress was raised in Los Angeles and attended Stanford for college and medical school. As an undergraduate, Zack worked in the laboratory of the late Ben Barres, where he studied the molecular underpinnings of axonal injury in murine and Drosophila models. As a resident, Zack worked in the laboratory of Giles Plant as a post-doctoral scholar, where he focused on developing pharmacologic and cellular therapies for spinal cord injury. In the Veeravagu Lab, Zack is interested in utilizing big data approaches to study surgical outcomes, quality, and health-care delivery. Zack’s clinical interests include minimally invasive and robotic neurosurgery, motion preservation, adult deformity, the cranio-cervical junction, and spinal oncology.

Martin N. Stienen, MD, FMH, FEBNS
Clinical Instructor, Neurosurgery

Martin studied Medicine in Germany, where he earned his MD for experimental research on electrophysiological properties of glial cells in 2011. He did his neurosurgery residency in St.Gallen, Geneva and Zurich (Switzerland). Martin is board-certified for neurosurgery in Switzerland (FMH), and he was appointed „Fellow of the European Board of Neurological Surgeons“ (FEBNS). Besides the clinical patient care, Martin has a strong interest in outcomes research, and he has been focusing on the systematic validation of an objective measure of function (the Timed Up and Go (TUG) test) for patients with diseases of the spine. Martin has submitted his habitation thesis on „Outcome measures in modern neurosurgery“ to the University of Zurich in March 2018. He has been supported by several funding bodies, including the AO Spine and the Swiss Society of Neurosurgery.


Ian Connolly, MS
Medical Student

Ian is a medical student interested in neurosurgery, with scholarly concentration in clinical research/neuroscience, behavior, and cognition. He completed his undergraduate and graduate degrees in mechanical engineering at Stanford where he also played on the men's volleyball team. 


Kunal Varshneya
Medical Student

Kunal Varshneya is a first-year MD student at Stanford University interested in the intersection of science, technology, and neurosurgery. His research has focused on improving malignant brain tumor and spinal pathology therapy, and has published numerous peer-reviewed manuscripts in journals such as Journal of Neurosurgery, Spine, Neurosurgery, and Journal of Clinical Neuroscience. During his time off after completing an undergraduate degree in neuroscience from the University of Southern California, Kunal began developing a mobile platform that uses algorithms to match and connect patients similar to one another - a project he hopes to bring to patients and hospitals nationwide. Kunal was born in the Netherlands, grew up in Cupertino, California and hopes to one day be a practicing surgeon in the Bay Area.


Tej D. Azad, BIOM-MS
Medical Student

Tej Azad is an MD/MS student at Stanford and aspiring neurosurgeon-data scientist interested in predictive modeling and neurosurgical outcomes. Tej has published more than 50 peer-reviewed manuscripts in journals such as JAMA, Lancet, and Science Translational Medicine. During medical school, Tej pursued advanced training in computational biology and statistics, culminating in a Master’s degree in biomedical informatics from Stanford funded by a TL1 training grant from the National Institutes of Health and a Doris Duke Charitable Foundation fellowship. Tej’s research has been supported by the American Association of Neurological Surgeons, Council of State Neurosurgical Societies, and the American Brain Tumor Association. Tej graduated summa cum laude from Washington University in St. Louis with a degree in neuroscience and originally hails from Floyds Knobs, Indiana.


John Ratliff, MD, FACS
Professor of Neurosurgery
Lab Affiliate

Dr. John Ratliff is Professor and Vice Chair of Neurosurgery, Departmental Quality Officer, and Co-Director of the Spine and Peripheral Nerve Surgery Division. As a spine surgeon, he treats a diverse array of degenerative spinal conditions. He has a specific research emphasis on quality improvement, decreasing complications in spine surgery, and improving surgical treatment of intramedullary spinal cord tumors.