My mom's had it for over 30 years. She first went to the doctor because she was having numbness in her limbs, and problems with balance (this would have been around 1976 or so). The doctors initially didn't know what she had, but said she was suffering from MS like symptoms. In 1981 we moved to WA from the Bay Area because the cooler climate was better for her. (Heat made her symptoms worse.) It took 12 years before she was officially diagnosed as having MS. One thing I've learned about the disease is that it affects everyone in different ways. Some people have one flare up, recover, and are fine afterwards. Some people's symptoms progressively get worse and then stablilize (sp?) at a specific point. Unfortunately for my mom, her MS is progressive. She's now in a nursing home and unable to care for herself.
Now, that being said, there have been huge strides in the advancement of MS treatments. There's a lot more options for people who are diagnosed today, then when my mom was officially diagnosed over 20 years ago. My mom's disease has progressed too far for any of the new drugs to be of any use, but it gives hope for newly diagnosed people.
On a somewhat funny note. When my mom was first diagnosed, her doctor actually gave her business cards to hand out that read, "I'm not drunk, I have MS". Thankfully, doctors seems to be a bit more tactful these days!