1 A person is unconscious for more than a few seconds. 2  Confusion occurs with other signs of a stroke, such as sudden weakness, numbness, inability to move, changes in vision, or slurred speech.3  Confusion and memory loss develop quickly, over a few hours or days. 4  This is called delirium. A person is unconscious for more than a few seconds. 2  Confusion occurs with other signs of a stroke, such as sudden weakness, numbness, inability to move, changes in vision, or slurred speech.