Baltimore County executive Roger B. Hayden suffered a ruptured blood vessel in his brain yesterday, and is a patient at Johns Hopkins Hospital today where he will be undergoing tests for the next several days.

Mr. Hayden, who spoke to this reporter on the telephone just before 10 a.m. from an intensive care unit at Hopkins, said the incident is the result of a condition he's had for years. "I'm hanging in there" he said, explaining that there is a tangle of tiny blood vessels over his right eye which have periodically caused painful headaches, but this is the first time one has burst.

The tests will help determine what treatment is needed, Mr. Hayden said, adding that the worst-case scenario could involve some loss of vision in his right eye.

The incident began when Mr. Hayden, 49, awoke at home with a headache yesterday morning, according to Robert Hughes, the county executive's spokesman.

Dr. Kyra Becker, a neurologist, is treating Mr. Hayden. He will undergo an MRI and an angiogram in the next two days.