Complex migraine: Serene Branson's gibberish caused by "headache?"

(CBS) Migraines can cause more than pain. Just ask Serene Branson, the TV reporter whose recent on-air speaking difficulty is now believed to have been caused by a so-called "complex" migraine.

What's a complex migraine? It's an unusual "presentation" of the neurological disorder - one that can cause vision disturbances, vertigo, and numbness as well as the sort of speech difficulty that Branson experienced. The condition usually develops before the age of 40, according to "Is It Stroke, or Something Else," an article published in the Jan. 2010 issue of "The Journal of Family Practice:"

Many viewers who watched Branson's unsettling on-air episode thought she might have suffered a stroke. That's not surprising. Even doctors can having trouble telling stroke from complex migraine, which is considered one of several stroke "mimics."

Migraines are treated with a wide range of drugs, as well as with biofeedback and behavioral therapy, according to the article. In most cases they are benign. But evidence suggests that people who have had complex migraine face a greater risk for stroke.