Dr. Cohen is chairman of the American Society of Pediatric Neurosurgery and Director of Pediatric Neurosurgery at Johns Hop Hospital. He was Director of Neurosurgery at Boston Children's Hospital and Professor of Neurosurgery at Harvard Medical School.

Dr. Cohen is a specialist in minimally invasive surgery for pediatric neurosurgery, particularly pediatric brain tumors, dedicated to enhancing the safety and effectiveness of neurosurgical procedures. He has published more than 170 academic papers and published two books.