CNOS Leadership

Matthew Johnson, M.D., M.P.H., F.A.A.N.S.


Medical Education : MD, University of Nebraska Medical Center; MPH, Tulane University School of Public Health & Topical Medicine; BS, Tulane University

Residency & Internship : University of Nebraska Medical Center

Dr. Matthew Johnson was born and raised in Omaha, NE. Dr. Johnson joined the staff of CNOS after completing his training at UNMC in 2007.

Dr. Johnson is a member of the American Association of Neurological Surgeons, the Congress of Neurological Surgeons, the Midwest Neurosurgical Society, the Iowa Medical Society and the Woodbury Medical Society.


He provides his surgical expertise for a wide variety of brain and spine disorders. He has special interest in Deep Brain Stimulation for movement disorders and is working with Mercy Medical Center to build a program to offer this life-changing surgery locally in the Siouxland area. He also has experience in Minimally Invasive Spine Surgery and has special training in Stereotactic Radiosurgery, which can often treat brain tumors with focused radiation rather than open surgery

Greg Carlson, PhD


Dr. Carlson has over 20 years of experience as a healthcare executive, serving 11 of those years as the CEO of a 500-bed community hospital in Owensboro, KY and 5 years as COO of Marian Health Center (now Mercy Medical Center) from 1990-1994. Dr. Carlson attributes his management success to building values based cultures, partnering with physicians, and implementing innovative programs to carry out the missions of organizations based on community needs.


In addition to his executive experience, Dr. Carlson has served as an Associate Professor and Director of Continuing Education at the University of Alabama at Birmingham, chair of Health Care Management at the University of South Dakota and visiting professor at the University of Minnesota and St. Leo University. He has also served as a healthcare consultant to many organizations focusing on strategic planning, organizational culture, integration strategies between physicians and hospitals, clinical quality, and has authored numerous publications including co-authoring the book Leading Healthcare Cultures: How Human Capital Drives Financial Performance.


Dr. Carlson earned his Masters of Health Administration degree from the University of Pittsburgh and a PhD in Health Services and Policy from the University of South Carolina, as well as his Bachelors in Business and Political Science from Southwest Minnesota State University.