Walavan Sivakumar, MD, is a fellowship-trained neurosurgeon with a focus on skull base and minimally invasive and endoscopic neursosurgery. A multiple award-winning doctor achieving SuperDoctor, Top Doctor and Medscape 25 Rising Star awards, Dr. Sivakumar has a particular interest and expertise in brain tumors, skull base tumors, pituitary/parasellar tumors, and intraventricular brain tumors, and he applies the keyhole concept, utilizing advanced neuroimaging and microsurgical techniques to minimize collateral damage to the brain. In addition, he treats patients at the Spine Institute at Little Company of Mary to help relieve and cure back conditions due to spine involvement. Dr. Sivakumar has over 40 peer-reviewed publications. He is the Director of Neurovascular Surgery at the Pacific Neuroscience Institute, and the Director of Neurosurgery at the Pacific Neuroscience Institute - South Bay.

Dr. Jian Guan is a fellowship trained neurosurgeon with a special focus on complex spine surgery at Pacific Neuroscience Institute. Dedicated to the care of patients with spine and neck conditions, he practices at PNI-South Bay / Spine Institute at Little Company of Mary in Torrance, California. With over 75 peer-reviewed publications, Dr. Guan has a particular clinical and research interest in ways of maximizing benefit to patients following neurosurgical procedures. He obtained his undergraduate education at the University of Michigan in Ann Arbor, and went on to receive his medical degree at Columbia University in New York City. National award highlights include the Julius Goodman Resident Award presented by the Congress of Neurological Surgeons, and the Charles Kuntz Scholar Award presented by the Joint Neurosurgical Spine Section.