[2] At age 16 he earned early admission into the University of California-Los Angeles, receiving an undergraduate degree[6] with a major in biology.
[16] From 1990 until 1997[16] Rezai attended New York University to study the brain,[6] receiving neurosurgical training under the direction of Joseph Ransohoff and Patrick Kelly[10] and beginning to focus on performing surgeries to implant neurostimulation devices in 1995.
[2] In August 2009[10] he left Cleveland Clinic to began working at Ohio State University,[1] where he was named the Stanley D. and Joan H. Ross Chair in Neuromodulation[10][5] and the associate dean for neuroscience.
[11] At Ohio State, he was a lead researcher in clinical trials involving neuromodulation for psychiatric disorders, traumatic brain injury, obesity, Alzheimer’s disease, quadriplegia, chronic pain, and headaches among others.
[25] While director of Ohio State's Center for Neuromodulation, in 2011 Rezai started an FDA clinical trial with the intent of implanting a chip to bypass spinal injury and restore limb movement using a brain–computer interface.
[17][30][31] On November 15, 2018, a team of investigators at RNI conducted the nation's first study with a tiny, pill-like micropellet implant made of a non-addictive, non-steroid medication that was placed into a patient's lower back to combat chronic pain caused from sciatica.
[35] In 2018,[36] at WVU, Rezai was lead researcher[37] of the first US human FDA trial[36] using focused ultrasound technology to open the blood brain barrier and reduce beta amyloid plaques in Alzheimer’s disease.
[41] The operation was a first-in-the-US clinical trial using deep brain stimulation for patients with treatment-resistant opioid use disorder,[39] and garnered the attention of media outlets like BBC[40] and the Washington Post.
[30][31] The holder of 60 US patents as of 2023, Rezai is involved with the study and implementation of neuromodulation procedures and devices in academia, government, and business.
"[10] Much of his research, papers and patents involve neuromodulation, deep brain stimulation (DBS), neurostimulation[1] and focused ultrasound technology to treat disorders such as Parkinson's, Alzheimer's,[31] and addiction.
[23] Around that time he was also part of a trial to treat chronic obsessive compulsive disorder with DBS, with the results published in 2006 in Neuropsychopharmacology.
[45] On May 3, 2016, at the Ohio State University Wexner Medical Center, surgeons performed brain stimulation surgery using an electrical lead attached to a pacemaker to control tremors from Parkinson's disease.
[20][46] Rezai was the principal investigator[38] in a 2019 National Institute on Drug Abuse funded study[39] to evaluate the safety and feasibility of deep brain stimulation for treatment of opioid addiction.
[7] While director of Ohio State's Center for Neuromodulation, in 2011 Rezai started an FDA clinical trial[26] in collaboration with scientists at Battelle Research Institute[47] with the intent of implanting a chip to bypass spinal injury and restore limb movement.
[42] With Rezai as lead researcher,[37] in 2018, the Rockefeller Neuroscience Institute was chosen as the initial site in the US for an FDA-approved[36] clinical trial using low intensity magnetic resonance–guided focused ultrasound (MRgFUS), for treatment of Alzheimer's disease.
"[54] In 2021, Rezai as principal investigator oversaw the launch a new trial of focused ultrasound for the treatment of opioid use disorder and other substance addiction.
[35] The wearable devices measure sleep patterns,[56] heart rate, other physiological functions, nervous system changes, as well as "psychological and behavioral factors."
In 2020 during the COVID-19 pandemic in West Virginia, Rezai and the team used this technology help identify and predict symptoms of viral infections,[57] publishing a paper on the project in 2021.
[63] He has appeared in live radio and television broadcasts in outlets such as 60 Minutes, CNN, NPR, PBS, BBC, MSNBC, ABC, NBC, The Discovery Channel,[11] Good Morning America, HBO, and others.
[11] He was listed in Castle Connolly’s Guide to America’s Top Doctors from 2000 until 2023[16] and received a North American Neuromodulation Society Lifetime Achievement Award in 2023.