Cocaine abusers, especially those who use the drug’s purer crack form, are more likely than others to suffer strokes or cerebral hemorrhages, researchers said. Dr. Patti Peterson, chief of neurology at Detroit Receiving Hospital, said a three-year study found that 3% of the 979 cocaine abusers admitted to the hospital suffered strokes or hemorrhages, the rupture or clogging of a blood vessel in the brain. Most of the abusers were young adults, with an average age of 35, she said. The rate of stroke in the general population of similar age is about 0.05%, Peterson said. She and Dr. Patricia Moore, a neurologist at the hospital, presented their findings at the annual meeting in Chicago of the American Academy of Neurology.