Coretta Scott King -- widow of slain civil rights leader Martin Luther King Jr. -- managed to say a few words on Friday and "clearly wants to communicate," but her physician said she might not fully recover from a stroke.

King, 78, suffered the stroke Tuesday morning when a blood clot became lodged in the part of her brain that controls speech, said Dr. Margaret Mermin. She has not been able to walk or speak since then.

In January, she was diagnosed with atrial fibrillation, which causes an irregular heartbeat and can increase the chance of stroke. Since then, she's had two "warnings of strokes," Mermin said, including one episode that caused her to lose speech for two hours.