Naritoku received his medical degree from Chicago Medical School and completed his internship in internal medicine at the University of Illinois in Chicago. He completed neurology residency training at Washington University in St. Louis. Following his residency, he completed a neuropharmacology and epilepsy fellowship also at Washington University.

Naritoku is board certified in neurology and clinical neurophysiology by the American Board of Psychiatry and Neurology, and is board certified by the American Board of Clinical Pharmacology. He is also a member of the American Academy of Neurology, the American Epilepsy Society, the American Academy for the Advancement of Science, the American Medical Association, the Society for Neuroscience, the chair of the education committee for the American Society for Clinical Pharmacology, and a member of the American Society for Clinical Neurophysiology.

Naritoku has published extensively on basic and clinical research and is the recipient of numerous grants. He also holds multiple United States patent awards. These include methods of treating traumatic brain injury by vagus nerve stimulation; methods of modulating aspects of brain plasticity by vagus nerve stimulation; and methods for improving learning or memory by vagus nerve stimulation.