Jerusalem ? Doctors said early today that they planned to begin reviving Israeli Prime Minister Ariel Sharon, a procedure that could provide the best opportunity thus far to assess the extent of brain damage he suffered because of a massive stroke.

The 77-year-old prime minister, who has remained in a medically induced coma for four days, continued today in critical but stable condition, said Dr. Shlomo Mor-Yosef, director of the Hadassah Hospital. Doctors were to begin easing his sedation and testing his responses, he said.

Sharon has hovered near death, connected to a respirator, since suffering a massive cerebral hemorrhage late Wednesday, and has undergone three delicate brain surgeries in the time since. Though he may survive, Sharon is not expected to return to his job as head of the Israeli government.