Former child star Frankie Muniz is just 27, but last week he had a "mini-stroke," TMZ reports. Friends got concerned when the Malcolm in the Middle star started having trouble talking and understanding what others were saying. Doctors aren't sure what caused it, and Muniz is still waiting for test results. But he's back on Twitter, USA Today reports: "I was in the hospital last Friday. I suffered a 'Mini Stroke', which was not fun at all. Have to start taking care of my body! Getting old!" he tweeted yesterday.