Dr. Simmons is Triple Board-Certified by the American Board of Clinical Neurophysiology, American Board of Psychiatry and Neurology, & American Board of Sleep Medicine. He is the Founding-Director of Comprehensive Sleep Medicine Associates, PA (CSMA), with locations in Conroe, The Woodlands, the Houston Medical Center and Sugar Land, Texas. Dr. Simmons founded and directed The Sadler Clinic Sleep Disorders Center (s) from 1999-2012. He is also the Founding-Director of the Sleep Education Consortium, a 501 (c) 3, non-profit organization that focuses on enhancing the education of doctors and the community on sleep disorders.

After receiving his Neurology training at Washington University, Barnes Hospital in St. Louis MO in 1990 he went on to obtain fellowship training in Sleep Disorders Medicine at Stanford University Medical Center and then in Neurophysiology and Epilepsy at the University of California, Davis, Department of Neurology, Sacramento CA. On completion of his training he joined the faculty at UCLA and held the positions of Co-Director of the UCLA Sleep Disorders Center in Los Angeles and Director of the Clinical Neurophysiology Laboratory, UCLA / Olive View Medical Center Sylmar, California.
While there at UCLA he was active in training other physicians in sleep disorders medicine. After six years he transitioned out of UCLA and into his current positions.

As a Neurologist, Dr. Simmons treats patients with a wide range of neurological conditions but he spends most of his practice evaluating and treating patients with sleep disorders. He has dedicated his career to provide the highest level of diagnostics testing to identify the full spectrum of sleep disorders. He has been on the cutting edge of implementing new technologies in the sleep laboratory, including esophageal pressure monitoring to diagnose patients with the Upper Airway Resistance Syndrome.
Dr. Simmons evaluates pediatric patients as well as adults, and is amongst the few sleep specialists in the United States who can competently diagnose children who have Hyper Activity Attention Deficit Disorder caused by a subtle sleep disturbance such as the Upper Airway resistance Syndrome or Period Leg Movements of Sleep. Implementing state-of-the-art technology has been a passion of Dr. Simmons and he is actively working to implement computer technology in the field of medicine and more specifically, Sleep Disorders Medicine.
He is committed to teaching both medical professionals and the general public on sleep and sleep disorders. As the Director of the Sleep Education Consortium Dr. Simmons coordinates ongoing conferences to enhance the knowledge of sleep disorders of primary care physicians so they can better serve their patients.