Prime Minister Ariel Sharon was one of the lucky ones, suffering no damage to his brain as a result of his mild "cerebrovascular accident" (CVA), in which a small blood clot temporarily blocked a blood vessel in his brain. Despite his obesity and lack of exercise, Sharon's "good genes" and his non-smoking history helped to pull him through as he was pronounced to be in "excellent condition," by his doctors at Hadassah University Medical Center in Jerusalem's Ein Kerem. Prof. Tamir Ben-Hur, head of Hadassah's neurology department, told The Jerusalem Post on Monday that it was impossible to differentiate in Sharon between a "mini-stroke" (also known as a transcient ischemic attack, or TIA) or a mild stroke, as the border between the two is not clear. Usually, an TIA is caused by a blood clot that forms anywhere in the body and gets stuck in a blood vessel in the head, depriving nerve cells of oxygen-carrying blood. TIAs last for less than a day - even as short as an hour or two - and resolve themselves when the clot disintegrates on its own. Ben-Hur denied initial press reports that the prime minister - due to mark his 78th birthday in February - lost consciousness at any point before or after reaching Hadassah on Sunday night. "He was not even confused, but he had slurred speech upon admission, which could give the impression of confusion and being unable to answer questions properly," Ben-Hur said. "He did not suffer any paralysis, even temporarily." Among the tests Sharon underwent was magnetic resonance imaging (MRI) and computerized tomography (CT) of the head, neck and heart to make sure there are no more clots or narrow blood vessels. The prime minister, Ben-Hur stressed, did not need any catheterization of the brain or clot-busting with special drugs, which is available at Hadassah and several other Israeli hospitals. Asked what drugs Sharon was taking, Hadassah's chief neurologist said he received the blood-thinning agent heparin, and that Sharon would be given an injection to keep at home so he will not be forced to come to the hospital for it in the future. The drugs he will take give Sharon an "excellent prognosis," said Ben-Hur, as they will greatly minimize the risk of a repeat TIA or CVA. He was not given aspirin yet, but he may be given that simple drug on a long-term basis to make the blood "less sticky." Sharon was "acting like himself, charming and funny, with his usual spark in his eyes," Ben-Hur said. However, the prime minister will return later for another checkup at Hadassah to investigate a small sign of clot "over-mobilization" in the heart wall, which "is normal in many healthy people and doesn't necessarily mean anything." Besides for Sharon's obesity - Ben-Hur did not not want to disclose his actual weight - Sharon enjoys very good health." Even his cholesterol level is not excessive, he added. Having good genes - his parents who died at advanced ages - is protective against getting a stroke and being hurt by one, said Ben-Hur, but it is certainly no guarantee. The Hadassah doctors did not have time to encourage Sharon to exercise and lose weight, although his personal physician, Sheba Medical Center Director-General Prof. Boleslav Goldman, has said: "I have advised this for 30 years, and I hope to continue to discuss it with him for another 30 years." Ben-Hur said that the generous servings of lamb, steak and kabab served at Sharon's ranch for guests over the weekend, and which the prime minister probably ate, "did not cause the stroke." Ben-Hur said he hopes the public will absorb the good news not only that Sharon is well, but that CVA can be prevented by proper lifestyles, and that a revolution in stroke diagnosis and treatment has been achieved. "Stroke units in all the hospitals must be at the top of medical priorities, as heart units were decades ago. There are excellent professionals in Israel who can man them." Dr. Isabelle Koren-Lubetzki, the new head of Shaare Zedek Medical Center's department of neurology who was asked to comment, said she did not examine Sharon and thus could not directly discuss his case. But in general, the most common type of stroke is ischemic, in which a part of the brain is oxygen deprived, while a minority of patients suffer from a brain hemorrhage, often due to an aneurysm (explosion of a vessel). Ischemic strokes vary in their damage, depending on where the blood clot is in the brain or carotid artery in the neck; how much of the brain is starved; and for how long. If the affected area is not large and not in a critical location, the patient gets better, sometimes without treatment. Nevertheless, patients should not ignore symptoms of severe headache, confusion, weakness, paralysis on one side of the body or inability to speak, she said. The important thing is to get to the hospital as quickly as possible, Koren-Lubetzki added. Stroke patients who are disabled can improve with physiotherapy, occupational and speech therapy and others available in the hospital's rehabilitation department.