Neurosurgery Clinical Instructors and Fellow
Cerebrovascular and Endovascular Neurosurgery
Dr Frantzias was born in Cyprus and moved to Edinburgh where he attended medical school. He completed his neurosurgical residency in London, UK. During residency training, his research was focused on subarachnoid hemorrhage and spontaneous intracerebral hemorrhage. He also completed a Masters degree in neuroimaging. As a clinical instructor, Joseph will work with Dr Steinberg in open cerebrovascular procedures including treating aneurysms, arterio-venous malformations and moyamoya disease. He enjoys running, swimming, reading non-fiction, and traveling.
Neurosurgical Oncology and Radiosurgery
Dr. Hori received his MD from Sapporo Medical University, Japan, and during that time he served as a Medical Student Research Fellow in the Department of Pharmacology. He explored the functional role of the SIRT1 gene, a longevity-associated gene, and its association with various conditions such as muscular dystrophy. He also completed a Visiting Student Research Fellowship at the Health Sciences University of Hokkaido and participated in Human Genetics projects focusing on an association between the 27-bp deletion and 538G>A mutation in the ABCC11 Gene.
After graduating from medical school, Dr. Hori completed a neurosurgery residency at National Hospital Organization Okayama Medical Center in Japan. Subsequently, he completed a Stereotactic and Functional Neurosurgery Fellowship and then a Neurosurgical Oncology and Radiosurgery Fellowship at The Cleveland Clinic. He also completed an International Neurosurgery Fellowship at Boston Children's Hospital, Harvard Medical School. In 2022, he moved to Stanford University as a postdoctoral fellow, and under the supervision of Dr. Anca Pasca, he participated in brain organoid research focusing on hypoxic brain injuries.
Since July 2023, Dr. Hori has been working as a Clinical Instructor (Neurosurgical Oncology and Radiosurgery) in the Department of Neurosurgery at Stanford under the supervision of Drs. Steven D. Chang and Antonio Meola. His clinical interests include malignant brain and spine tumors in both adult and pediatric patients. His clinical research focuses on the application of minimally invasive treatments such as laser interstitial thermal therapy, focused ultrasound, and radiosurgery to treat various neurosurgical conditions. His current lab research aims to develop an organoid model for radiation-induced brain injuries and a high-throughput screening platform to identify novel therapeutic compounds, for which he received a Clinician Educator Grant from Stanford University Maternal and Child Health Research Institute. Outside of medicine, he enjoys playing music including guitar and drums.
Stereotactic, Functional, and Epilepsy Neurosurgery
Arjun Khanna is a fellow in functional and stereotactic neurosurgery at Stanford for the 2023-2024 year. His clinical interests are in the development and use of closed-loop neuromodulation systems for epilepsy and movement disorders. His academic interests involve collecting human electrophysiological data to investigate the neural basis of human cognition, with particular emphasis on speech and language. He obtained a BS from Duke University, MD from Harvard Medical School, and completed residency in neurosurgery at Massachusetts General Hospital.
Dr. Kevin K. Kumar was born in New York City and grew up in Long Island, New York. He attended college at Cornell University where he majored in Biological Sciences with a concentration in Neurobiology and Behavior. After graduation, Dr. Kumar joined the Medical Scientist Training Program (MSTP) at Vanderbilt University to earn his combined MD/PhD. He completed his PhD in Neuroscience in the laboratory of Dr. Aaron Bowman, where he studied the regulation of manganese in both Parkinson’s and Huntington’s disease using high throughput screening, induced pluripotent stem cells, and untargeted metabolomics. He then began his neurosurgery residency at Stanford. As a resident, Dr. Kumar completed an NIH-funded postdoctoral fellowship in the laboratory of Dr. Marius Wernig in the Stanford Institute for Stem Cell Biology and Regenerative Medicine. His work focused on developing a platform to replace microglia in the brain as a novel therapy for neurodevelopmental disorders.
From 2023-2024, Dr. Kumar will serve as Clinical Instructor in Pediatric Neurosurgery at Lucile Packard Children’s Hospital at Stanford. In addition to his clinical duties, he will continue to advance cellular therapeutics for pediatric neurological diseases.
Outside of neurosurgery, Dr. Kumar enjoys traveling, reading about history and world affairs, high-intensity interval training, and playing tennis.
Skull Base Surgery
Dr. Ljubimov is a Clinical Instructor in the Department of Neurosurgery. He was born in Kiev, Ukraine. After completing his B.S. at the University of Southern California in biochemistry, Dr. Ljubimov continued at the University of Southern California for his MD and MS in biomedical engineering in a combined program. Dr. Ljubimov completed his neurosurgical residency at Cedars-Sinai Medical Center with a clinical focus on tumor surgery and research in nanotechnology for drug delivery across the blood-brain barrier and modulation of the tumor microenvironment and genetic tumor models. In his fellowship at Stanford, Dr. Ljubimov will be working with Dr. Juan Fernandez-Miranda to obtain specialized training in advanced endoscopic endonasal and open skull base techniques, with the ultimate goal of becoming a universal tumor surgeon being able to treat a range of brain tumors, skull base pathologies, and pituitary lesions. In his spare time, he enjoys playing classical piano.
Dr. Marianayagam studied medicine at Tel Aviv University. He completed his internship in General Surgery at Duke University Medical Center followed by Neurosurgery residency training in Israel. He has completed fellowships in Neurosurgical Oncology at Yale-New Haven Hospital and Stereotactic Radiosurgery and Neurosurgical Oncology at Stanford. Before medical school, Dr. Marianayagam completed a PhD in Biophysical Chemistry at the University of Cambridge followed by postdoctoral research fellowships at the University of Sydney and the University of California, Berkeley. His current clinical and research interests include multimodal treatment of brain and spine tumors, minimally invasive spine surgery, stereotactic radiosurgery for mood disorders and addiction, and utilizing computational methods to improve patient outcomes in spine surgery.
Neurosurgical Neuro-Oncology and Stereotactic Radiosurgery
David Park, MD, PhD, is a neurosurgeon who graduated medical school from the Catholic University of Korea in Seoul, South Korea. He then completed his internship and residency training in the Department of Neurosurgery, Seoul St. Mary’s Hospital. He became a board-certified neurosurgeon in South Korea in 2014 and then completed his 2-year fellowship in the same hospital in the fields of Brain tumor surgery and Skull base surgery. During his residency training, he was selected to attend graduate school while practicing neurosurgery as a trainee. He focused on combination therapy using engineered stem cells along with the conventional treatment, and successfully defended his PhD thesis titled “Combination therapy for gliomas using temozolomide and interferon-beta secreting human bone marrow-derived mesenchymal stem cells.” in 2015.
After completing his fellowship in South Korea, Dr. Park moved to Singapore in 2016. He worked as a clinical fellow (clinical associate) for one year in the National Neuroscience Institute, focusing on Neurosurgical Oncology and Skull base surgery.
In 2017, Dr. Park then joined Dr. Christian Badr’s lab at the Massachusetts General Hospital, Harvard Medical School, as a postdoctoral research fellow to perform translational research on glioblastoma to complement his clinical expertise. His research focused on the role of fatty acids and lipid metabolism in glioblastoma. During this one-year postdoc research fellowship, he could successfully show that certain fatty acids can accelerate tumor growth in mouse orthotopic glioma models and identified a desaturase enzyme as a key in this process.
During this period, in addition to his work in the lab, Dr. Park launched his own start-up business based on his invention. He came up with the idea of a real-time intraoperative diagnostic tool for tumor detection during glioma surgery. The tool is a diagnostic device that uses intrinsic fluorescence spectroscopy on top of fluorescence imaging to improve the detection of residual tumors during glioma surgery in a very practical way. He collaborated with bioengineers at M.I.T. to develop a prototype and received seed funding from the MIT Sandbox Innovation Fund. As an MIT Sandbox program alumnus, he continues to work on this project.
In 2020, Dr. Park joined the North Shore University Hospital, Zucker School of Medicine at Hofstra/Northwell in Long Island, New York, as a Neurosurgical Oncology Fellow (Teaching Associate). During this one-year fellowship, he worked with Dr. Michael Schulder with a focus on brain tumor surgery including laser interstitial thermal therapy (LITT) and stereotactic radiosurgery (SRS). He could perform brain tumor surgeries using the diverse tools, such as, microscope, endoscope, exoscope and fluorescence guidance.
From July 2021 to June 2022, Dr. Park completed a Neurosurgical Oncology and Radiosurgery Fellowship at the Cleveland Clinic in Cleveland. He devoted his efforts to minimally invasive neurosurgical techniques such as LITT and Gamma Knife SRS, as well as awake brain tumor surgery under guidance of Drs. Gene Barnett, Lilyana Angelov, and Ali Mohammadi.
In July 2022, Dr. Park joined the Department of Neurosurgery at Stanford University as a Clinical Instructor. Dr. Park now works with Drs. Steven D. Chang and Antonio Meola in the field of Cyberknife stereotactic radiosurgery and Neurosurgical oncology.
Robert Kim, MD, MS
Robert (Bobby) grew up in Baltimore, Maryland. He attended the University of Maryland at College Park and graduated with a Bachelor of Science in Neurobiology and Physiology. He then started working as a Navy research contractor at the Naval Medical Research Center, Silver Spring, Maryland where he developed and tested resuscitative products on large animal models. He then moved on to obtain his Master of Science in Biomedical Science at Chicago Medical School, Rosalind Franklin University, North Chicago, IL. He matriculated into Chicago Medical School and completed his medical education with AOA. He was heavily involved in clinical research both in medical school and in residency.
Amit Persad, MD
Neurosurgical Neuro-Oncology and Stereotactic Radiosurgery
Amit Persad is a neurosurgeon trained at the University of Saskatchewan in Canada. He joins the Neurosurgery team at Stanford University for further training in neurosurgical oncology and radiosurgery. Amit has varied research interests but is interested in radiosurgery outcomes as well as the role of inflammation in brain tumors.