What disease might mimic multiple sclerosis?

Several potentials: Cadasil, lupus, arteritis, clippers, pernicious anemia, cervical spondylosis, lyme disease, CNS lymphoma, sjogren's, melas. If you get the point, ms may be hard to diagnose, and often need to exclude other explanations. Patterns may or may not be different, and sometimes it is important to get testing and even several opinions.

Many: As dr. Mechanic said, there are mimics. Please see his answer for these. One thing he did not mention, is atypical migraines.