JERUSALEM, Jan. 12 (Xinhuanet) -- Israeli Prime Minister Ariel Sharon remained in critical but stable condition, Jerusalem's Hadassah University Hospital treating him said on Thursday.

    "His heart rhythm is regular. In the evening he will undergo a routine CT scan," said a Hadassah statement.

    Thursday's statement came following no change in the prime minister's condition overnight.

    Sharon, 77, showed slight but significant improvement in his condition as he began to breathe on his own on Monday and reacted to stimulation in his four limbs by Tuesday.

    Doctors are expected to completely stop the intravenous drip of sedatives that have kept Sharon in a medically induced coma over the last week after he suffered a massive stroke and cerebral hemorrhage on Jan. 4.

    They can only assess the extent of the brain damage Sharon may suffer after the dissipation of the sedatives, said the doctors,stressing that the process could take days.

    As doctors pronounced that there was no immediate danger to the prime minister's life, a controversy surrounding Sharon's medical treatment continued.

    Sharon's doctors were under further criticism for concealing the diagnosis of cerebral amyloid angiopathy (CAA), a brain disorder and one of the principal causes of brain bleeding in elderly people.

    Recent studies have shown that the administration of blood-thinning drugs to a patient with this condition is a "significant factor" in causing cerebral hemorrhaging.

    Senior executives at the hospital admitted this week that the hospital's doctors decided to give the prime minister blood thinners despite the diagnosis of CAA, which was detected last Wednesday.

    A member of Sharon's medical team said on Wednesday that the information about the brain disease diagnosed after his first stroke on Dec. 18 was concealed out of "political reasons", local TV Channel 10 television reported.

    The unnamed source said there was fear that if made public, the information would be used against Sharon and his Kadima party, particularly in light of the fact that CAA has often been associated in medical literature with Alzheimer's Disease.

    Sharon's sudden illness has plunged Israeli politics into uncertainty as the country is heading toward the March 28 general elections.

    Recent polls showed that Sharon's newly founded centrist Kadima party is expected to fare well in the race even without him at the helm, followed by the right-wing Likud Sharon bolted in November and the center-left Labor party. Enditem