Physician Profiles


Shahin A. Sadik, MD, Q.M.E.

Dr. Shahin Sadik is one of the founding physicians of Universal Pain Management. Dr. Sadik graduated with a medical degree at Eastern Virginia Medical School of Medical College of Hampton Roads. He then completed his residency in anesthesiology and fellowship training in pain management at the University of Pennsylvania. Currently, Dr. Sadik works as a pain management physician and Medical Director at Universal Pain Management in California.

Board-certified by the American Board of Anesthesiology with special qualification in pain management and also by the American Board of Pain Medicine, Dr. Sadik has vast experience managing chronic pain. In addition to his duties at Universal Pain Management, Dr. Sadik holds a faculty position at the University of Southern California, Keck School of Medicine as Assistant Professor of Anesthesiology.

Ray d'Amours, MD, Q.M.E.

An accomplished author, instructor, and physician, Dr. Ray d'Amours earned his medical degree in 1985 with Distinction in Research from the University of Miami School Of Medicine. He then served the Naval Aerospace Medical Institute as a student flight surgeon and the U.S. Navy Test Pilot School as flight surgeon. After his naval service, Dr. d'Amours completed his residency in anesthesiology at the University of Pennsylvania.

Practicing in pain management since the early '90s, Dr. d'Amours moved to southern California in 2002, when he joined Universal Pain Management. Concurrently with his duties as partner at Universal Pain Management, he works as an assistant clinical professor of anesthesiology at the Keck School of Medicine for the University of Southern California.

Dr. d'Amours is certified by the American Board of Anesthesiology with special qualifications in pain management, by the American Board of Interventional Pain Physicians, and by the World Institute of Pain as a fellow in interventional pain practice. Dr. d'Amours has authored several scientific papers and book chapters on pain management, as well as delivered various lectures on the subject across the U.S.




Francis X. Riegler, MD, Q.M.E.

Dr. Francis Riegler is also one of the founding physicians of Universal Pain Management. Dr. Riegler earned his medical degree from Case Western Reserve University in Cleveland, Ohio. He then completed his residency training in anesthesia at Michael Reese Hospital and Medical Center in Chicago, where he was also Chief Resident in his final year. He also has an MBA degree from the University of California at Irvine. Dr. Riegler currently resides in California, treating patients as a pain management physician with Universal Pain Management and holding a faculty position at the University of Southern California Keck School of Medicine as an assistant professor of anesthesiology.

Dr. Riegler is an expert in the daily management of chronic pain. He is board-certified by the American Board of Pain Medicine, by the American Board of Interventional Pain Physicians, and by the American Board of Anesthesiology with a special qualification in pain management. He is also a lifetime member of the American Society of Interventional Pain Physicians and executive director of the California Society of Interventional Pain Physicians.

Daniel Alves, MD, MPH

Daniel Alves, MD, MPH specializes in the treatment of people with both acute and chronic pain syndromes, including neck and low back pain, joint pain, and complex regional pain syndrome. He completed his medical degree at Loma Linda University in 1996. This was then followed by a residency in Preventive Medicine. During this time, he completed a Masters in Public Health. He later worked as a faculty member at Loma Linda University until he decided to pursue his passion of musculoskeletal and pain medicine. He moved to Milwaukee where he trained at the Medical College of Wisconsin where he was Chief Resident in his final year. From there he returned to Southern California  to undergo further specialization at the prestigious UCLA-PM&R Pain Fellowship. 

In addition to providing all forms of interventional techniques such as peripheral and spinal cord stimulators, intrathecal pump implantation and management, he is also trained in performing diagnostic electromyography and nerve conduction studies (EMG and NCS) which helps establish peripheral nerve pathology. In his spare time, he enjoys running, yoga, cycling and soccer.

Kevin Kohan, D.O., Q.M.E. 

Dr. Kohan is Board Certified in both Pain Medicine and Physical Medicine and Rehabilitation.  He completed both his undergraduate training at UCLA, and medical training at Midwestern University with honors. Subsequently, he performed his residency in Physical Medicine and Rehabilitation at Einstein Medical College. During his residency training, Dr. Kohan pursued several pain and spine research projects, an undertaking that resulted in several presentations and awards at national and international medical conferences and has published in pain and physical medicine and rehabilitation journals.


Dr. Kohan performed his pain medicine fellowship at University Cincinnati where he performed extra training in research and regional anesthesia.  He is an active member of American Society of Interventional Pain Physicians, American Academy of Pain Medicine, American Academy of Physical Medicine and Rehabilitation, and the International Society of Interventional Spine.  His interests are in spine, joint pains, headaches, and Complex Regional Pain Syndrome. During his spare time he enjoys spending time with his family engaging in several outdoor activities such as hiking, biking, and traveling.


Arvinder Gill, D.O.

Dr. Gill is board-certified with America board of Anesthesiology in Anesthesiology and Sub specialty of Pain Medicine. He completed undergraduate training at the University of Wisconsin Parkside graduate and obtained his medical degree at Midwestern University. His residency training in Anesthesiology was at University at Buffalo, and he completed his training with a fellowship in Pain medicine at University at Buffalo. He also served as a Chief Resident during his final year in the residency program.

His special interests include cancer pain, complex regional pain syndrome and implantable devices for treatment of chronic pain. Dr. Gill is a member of American Society of Anesthesiologists. He family includes his wife and twin daughters. He enjoys travelling, music and outdoor activities.


Rohit Choudhary, MD

Dr. Choudhary specializes in chronic pain management and anesthesiology. He completed his undergraduate studies at the University of Southern California and obtained his medical degree from Virginia Commonwealth University. Thereafter, he completed his Anesthesiology residency at the University of Illinois at Chicago and was elected Chief Resident in his final year. He stayed on for one additional year as an Interventional Pain Fellow where he developed skills to treat a variety of pain syndromes. Dr. Choudhary also was involved in a successful multi-disciplinary research project in which effective opioid sparing treatment methods were formulated to treat pain for post-surgical patients. In his spare time, he enjoys being involved in motorsports, cooking, and traveling.

Anna Krysiak, P.T.

Anna received her Masters degree in Science in rehabilitation and physiotherapy in Poland, Europe and became a licensed Physical therapist in the state of California in 1995. She has developed an excellent reputation as a therapist by treating all ages and variety of conditions. She encourages each person to maximize his or her recovery through and individualized therapy program, appropriate exercise and personal attention.

Her rehabilitation team specializes in geriatric, orthopedic and neurological disorders, pain management and therapy and wellness care.

Debbie Castillo, PTA, CWT

Debra has worked in physical therapy for over twenty-five years; she received her physical therapist assistant license in 1991. the majority of her caseloads have been working in out patient facilities, here in the Antelope Valley. She has had many clinical hours and continual education in myofascial release (MFR).

This has been very successful in treating soft tissue injuries related to neck, shoulder, back and lower extremities. MFR has also been successful when treating chronic pain complaints in promotion of a more functional active lifestyle. Her background as a certified weight trainer has worked on all levels of care depending on patient stability and tolerance.

Marc Reznikoff, L.Ac., Q.M.E.

Marc Reznikoff, L.Ac., Q.M.E. Marc Reznikoff is a licensed Acupuncturist and holds status as a Diplomate of Acupuncture. In addition he is a Qualified medical examiner (QME) for the state of California Workers Compensation Board. In 1993, he received his masters in Traditional Oriental medicine from pacific College of Oriental Medicine located in San Diego, California known as the "Harvard" of TCM colleges.

He also specializes in sports Medicine and has treated professional boxers (Big Bear, California) and Olympic athletes (invited to be on, and was a member of the U.S. Track and Field medical team for the 1996 Atlanta Summer Olympics).

Omid Mahgerefteh, D.C.

Omid Mahgerefteh, D.C., is a board certified chiropractor. He received his undergraduate degree in human biology and his doctorate in Chiropractic from Cleveland Chiropractic College of Los Angeles. Dr. Mahgerefteh is experienced in treating patients that have a variety of aliments from neck and back pain to pre and post surgical conditions.

He is experienced in treating work related as well as automobile related injuries. Dr. Mahgerefteh approaches his discipline with a holistic approach and works symbiotically with allopathic medicine.


Universal Pain Management Nurse Practitioners

Nurse practitioners are a vital part of the health care team at Universal Pain Management. A nurse practitioner (NP) is a registered nurse with advanced academic and clinical experience, which enables him or her to diagnose and manage most common and many chronic illnesses, either independently or as part of a health care team. A nurse practitioner provides some care previously offered only by physicians and in the state of California has the ability to prescribe medications. Working in collaboration with a physician, a nurse practitioner provides high-quality, individualized care for the patients of Universal Pain Management.
Ruth Pinter, NP
Sharon Sikand, PA
Richard Sandoval, PA
Ashley Morello, NP
Neisy Alvarez, PA
Suja Alexander, NP
Jaqueline Hattar, PA-C
Jennifer Scharler, NP


Donna Redmayne, Phd

Licensed Clinical Social Worker

Linda Raviv, LCSW