Dr. Cohen, aged 40 and born in Argentina, arrived at Hadassah Ein Karem Hospital in 2002. He established the hospital’s Endovascular Unit for the treatment of vascular defects and brain diseases and Hadassah hospital has since become a leader in the field. Dr. Cohen was a member of the surgical team that performed brain surgery on the Prime Minister.
Dr. Cohen was one of the pioneers of the ‘vertebroplastic technique" for veterbra reconstruction. He also specialized in neuroradiological intervention in the treatment of ruptured discs, vascular defects, vascular stenosis and damage to the blood supply to the brain. He was instrumental in developing tools for the treatment of these conditions.
Dr. Cohen completed his medical degree Magna Cum Laude in 1990 in Argentina. He specialized in neurosurgery from 1990 until 1996. In 1996 he started specializing in Neuroradiology Intervention in Buenos Aires, at one of the world’s leading hospitals in this field, all the while continuing to practice as a neurosurgeon.
Dr. Cohen has full practice of neurosurgery with a special interest in stroke, vascular and tumoral lesions affecting the central nervous system, head - neck and spine, including:

Professor Dmitrius Karussis, a Senior Neurologist at Hadassah and the Director of the new Multiple Sclerosis Center, worked in collaboration with the University of Athens, and with Professor Shimon Slavin, the Former Director of the Department of Bone Marrow Transplantation (BMT) and the BMT Laboratory at Hadassah. The scientists successfully isolated mesenchymal stem cells from the patients' bone marrow, cultured them under special conditions, and generated over 50 million stem cells within two months. The mesenchymal cells were marked so that the scientists could track them and verify that they reach the intended destination in the patient's body. The cells were then transplanted by a lumbar injection into the patient's spinal cord (into the spinal fluid of the CNS). Each patient served as his/her own bone marrow donor. 
According to Professor Karussis, the effectiveness of stem cells was initially studied in laboratory animals, where it was found that stem cells from bone marrow can reduce cerebral damage and improve the animal's functioning. During the past two years Professor Karussis has conducted clinical trials with 9 patients suffering from multiple sclerosis and with 16 patients suffering from ALS. "Most of the patients who underwent this process report an improvement in their condition," Professor Karussis said. The purpose of this initial trial was to identify undesired effects of the procedure. So far, no major safety issues have been encountered. However, a controlled larger scale clinical trial should be conducted in order to establish the safety and efficacy of the treatment.