Unfortunately, there are some other conditions that mimic MS and that's why it sometimes takes so long to get a diagnosis. It's just an elimination game.

Devics Disease is similar to MS (http://my.clevelandclinic.org/disord...s_disease.aspx).

Lyme Disease is similar (http://www.webmd.com/rheumatoid-arth...s-lyme-disease).

Plus, there are many different severities of MS. Someone might have a mild case of it with minimal symptoms while someone else might have a severe case of it with many different symptoms.