Our Medical Providers

The team at Avera Medical Group Neurosurgery has vast experience in their field. Our doctors and physician assistants are supported by a team of registered nurses with extensive training and capabilities

Michael R. Puumala, MD, FAANS

Dr. Puumala was born in Highland Park, Illinois. He earned his undergraduate degree from Carleton College in Northfield, Minn. in 1985, and went on to graduate from Mayo Medical School in Rochester, Minn. in 1990.

In 1991, he continued his studies at the Mayo Graduate School of Medicine and completed his residency in neurological surgery in 1996. Upon completing his work in Rochester, Dr. Puumala practiced in Mayo Clinics in Jacksonville Florida and Scottsdale Arizona, where he served as chief resident for the level I trauma center.

Dr. Puumala specializes in adult and pediatric neurosurgery, including all aspects of surgical problems related to the brain and spine; tumors of the brain and spine; cerebral vascular problems. He has board certifications from the American Board of Neurological Surgery (2001), the South Dakota Board of Medical Examiners (1996), the American Board of Neurological Surgery (1993), the National Board of Medical Examiners (1991) and the Minnesota Board of Medical Examiners (1991).

Daniel G. Tynan, MD

Originally from the Chicago area, Dr. Tynan joins Avera Neurosurgery after 17 years of neurosurgery practice. He received his MD from the University of Illinois at Rockford and completed his surgical internship and neurosurgery fellowship at the Mayo Clinic in Rochester, Minn.

Dr. Tynan moved to Sioux Falls in 2000 after 9 years of neurosurgery practice in Twin Cities, Minn. He is certified by the American Board of Neurological Surgery.

Dr. Tynan's general neurosurgical practice provides services involving surgery of the spine, which includes disc herniations, spinal stenosis, tumors, degenerative and traumatic spine problems, brain tumors, cerebral aneurysms, peripheral nerve surgery, endoscopic neurosurgery and functional neurosurgery for trigeminal neuralgia/epilepsy/chronic pain.

Hendrik B. Klopper, MD

Dr. Klopper received his undergraduate degree from Augustana College in Sioux Falls, SD. He went on to Graduate School and Medical School at the University of South Dakota School of Medicine, Vermillion. Dr. Klopper completed his internship in the Department of Surgery and his residency in the Section of Neurosurgery at the University of Nebraska Medical School in Omaha.

Dr. Klopper provides outstanding diagnosis and treatment of neurological conditions. "I chose Avera because it is a world class facility close to home."

Get to know Dr. Henk Klopper