I'm also very reassured to hear that there are so many people who get this sort of migraine! I've been having them since a teenager (i'm now 36) and they were worse when I was pregnant. Strangely I also had migraines immediately after giving birth!
I start off feeling a little strange and then my eyesight is affected - often I can only see half of objects and faces. The numbness then usually starts, normally in my hand or arm on one side and then it seems to travel up to my mouth, lips, tongue, gums, throat etc. My leg/foot are sometimes also affected. I get the sensation that my voice is echoing in my head as I speak and I too have experienced difficulty with speech and thought.
Once I tried to telephone a relative to tell them I was unwell but just couldn't get the number right even though I know it off by heart. I tried to look it up in my address book but just couldn't find their name. In hospital I was trying to tell the midwife that I was getting a migraine and I kept calling it a miblaine - I also couldn't tell her my name properly. I used to get a lot of nausea and vomiting also but can manage this better now. I make sure that I eat a piece of toast immediately when I get the initial symptoms and 2 paracetamol. Generally I start being sick if I have an empty stomach and take paracetamol. As long as I have eaten something the nausea and vomiting doesn't generally take hold and although I feel a bit groggy for the next few hours, the headache doesn't become too severe either. The other key is to rest. Sometimes the symptoms disappear after a little while so I start to do things (once I even went to work - big mistake) and then it comes back.
I hope that my experience will help some of you to manage your migraines too!