WASHINGTON — The Supreme Court on Monday allowed the execution of an Alabama inmate who, after several strokes, cannot remember the 1985 murder that sent him to death row.

The court’s opinion was unanimous, and there were no noted dissents. But three of the court’s more liberal justices filed concurring opinions saying the case presented a substantial legal question to which the court should return.

The inmate, Vernon Madison, was sentenced to death for killing Julius Schulte. In 2016, as Mr. Madison’s execution neared, he asked the state trial court to suspend his death sentence because he said he could not remember what he had done.

In a concurring opinion, Justice Stephen G. Breyer described Mr. Madison’s current condition: “He is legally blind. His speech is slurred. He cannot walk independently. He is incontinent. His disability leaves him without a memory of his commission of a capital offense.”