What Causes The Feeling Of Detached Arm During Migraine Attacks?

I am a female and have had migraines for quite a while. My doctor gave me an MRI about four or five years ago to check if my brain was all right; nothing was wrong. I get migraine auras and my migraines consist of flashes of light, loss of some part of my vision, nausea, bad headache, and the feeling my left arm is numb or detached/not part of my body. Today I woke up feeling like I would get a migraine, but only had a little headache, light sensitivity, and the feeling my arm was detached. The detached feeling still has not gone away and I am rather concerned. Is there something wrong?