Cornelius Robens, MD, PLLC Grayling Hospital. 1200 W. North Down River Rd. Grayling, MI 49738 231-642-5701 231-642-5706 Directions. Cornelius Robens, MD, PLLC Hauenstein Neuroscience Center. 220 Cherry St. SE, Hauenstein 1 Grand Rapids, MI 49503 616-685-5050 616-685-8962 Directions..