Frankie Muniz -- I Had Another Stroke

Frankie Muniz just had a frightening sense of deja vu ... because the 27-year old actor says he just suffered his 2nd mini-stroke in a year.

Frankie posted the health scare on his Twitter account, saying, "Almost a year to the day, I experienced another mini stroke. Hopefully that will be the last. Miserable." Muniz didn't say whether he needed any medical treatment.

Last year at this time ... Nov. 30th to be precise ... Frankie experienced blurred vision and had trouble speaking. Doctors diagnosed the episode as a mini-stroke, but said they didn't know what caused it.

We've reached out to Frankie -- who now lives in Arizona -- so far, no word back.