WASHINGTON--A team of specialists confirmed last night that President Eisenhower has suffered a blockage of a blood vessel leading to the brain--a condition generally called a mild stroke. Although they reported that Ike is "alert" and "in good spirits," doctors have recommended several weeks of rest and the State Department has said "it is to be assumed" that he will not attend the NATO summit conference in Paris next month.

The illness Eisenhower suffered on Monday had earlier been described as a "chill"; the change in diagnosis came after an examination made yesterday by the specialists. They reported that the blockage "has produced a slight difficulty in speaking," though "reading, writing and reasoning are not affected."

The statement emphasized that Eisenhower's disability is mild and transitory, and stated that it had nothing to do with his past heart attacks or any other illnesses. Vice President Nixon expressed confidence that the president "is fully capable of making" any major decision, although he stated that he didn't expect any major decisions to come up within "the next few days." He made his statement after speaking with Attorney General William P. Rogers, following the latter's conference with White House physicians.

Officials in Washington speculated that Nixon may take the President's place at the NATO conference, though some sources have suggested that other participating countries may prefer to go ahead with the meeting on a cabinet level, postponing a summit consultation until Ike could attend.

Secretary of State Dulles said a definite announcement will be made in two or three days on whether or not the president will cancel his special trip to Paris.

In New York, key stocks fell from one to seven points during the last 20 minutes of trading after receipt of the news about the nature of Eisenhower's illness.

Eisenhower, resting at home, was reported able to be up and about and capable of discussing recent events with interest and clarity.