The vigil at the bedside of Prime Minister Ariel Sharon continued over the weekend, with his condition remaining serious but stable and him remaining in a coma despite minimal doses of anesthesia. The spokeswoman for Hadassah University Medical Center in Jerusalem's Ein Kerem, where he is hospitalized in the seventh-floor neurosurgery intensive care unit, said Saturday night that an electroencephalogram showed activity in both brain hemispheres "that matches his state of [un]consciousness." She added that there had been no expansion of the brain's ventricles after the removal of a drainage catheter during minor surgery on Thursday night, which was a good sign, and all of the prime minister's vital signs remained stable. The update from the hospital was the first in more than 24 hours. Prof. Charles Weissman, the hospital's chief of anesthesiology who is a member of the team treating Sharon, said he was not on duty over the weekend. However, he said that many patients of the prime minister's age and medical history could take "weeks" to regain consciousness. He admitted that some, nevertheless, do not. "It's hard to tell at this point." Sharon had shown signs of tachycardia (an excessively rapid heartbeat) for a short time while in his hospital bed, Prof. Weissman, told The Jerusalem Post. Some unnamed doctors at Hadassah have expressed concern over the fact that Sharon still hasn't awakened from his coma despite the low remaining dose of anesthesia, given mostly to ensure his comfort. But the prime minister's body weight and the traces of anesthesia remaining in his system could be affecting the rate at which the prime minister wakes from his medically induced coma, they suggested. Responding briefly to criticism that Hadassah hasn't been divulging the whole story about its most famous patient, Hadassah Medical Organization deputy director-general Prof. Shmuel Shapira said on Channel Two's Meet the Press program: "We have told everything. We have nothing to be ashamed of. If we were to treat another patient in the same situation, we would have done the same."