"We don't know what happened two years ago or four years ago and we have no idea what will happen in the future," he said. "We just know that on Thursday evening there was a metabolic response in the brain of former Prime Minister Ariel Sharon."
Dr. Nicholas Schiff, professor of neuroscience at Weill Cornell Medical College, called the findings "interesting but ambiguous" and warned against reading too much into the tests.
Schiff, who did not participate in the testing and said he had not reviewed the research, said the FMRI is a widely used tool used for gathering data, but there is no consensus among researchers on interpreting the results. "In general, there are very few uses of FMRIs that unequivocally demonstrate awareness in patients that appear unresponsive," he said.
Sharon was a highly decorated military officer who fought in three wars before entering politics in the 1970s and serving in a series of top ministerial posts. He was elected prime minister in 2001 and led Israel for the next five years until he was incapacitated.
Shortly before his stroke, he directed a unilateral withdrawal of Israeli troops and settlers from the Gaza Strip, ending a 38-year military occupation of the territory, bolted his hard-line Likud Party and established the centrist Kadima Party. He appeared on his way to an easy re-election when he suffered the stroke. His deputy, Ehud Olmert, took over and was elected prime minister a few months later.
Sharon had a first, small stroke in December 2005 and was put on blood thinners before experiencing a severe brain hemorrhage on Jan. 4, 2006. After spending months in the Jerusalem hospital where he was initially treated, Sharon was transferred to the long-term care facility at Sheba Medical Center near Tel Aviv.
After his second stroke, doctors performed several extensive emergency brain operations to stop cerebral hemorrhaging. After a long stay at the hospital, he was taken for a brief period to his home in southern Israel. He was rushed at least once into intensive care for dialysis after his kidneys began failing.