What Causes Debilitating Migraines And Numbness On Left Side Of Head?

my 16 year old daughter has had debilitating migraines x 6 months. no migraine meds have worked. nor has an osteopath, neurologist or chiropractor. Shes had an mri, with mild flare on the right side, which do not image. will be repeating in 3 months. Dr. thinks its an old vascular something. also new, experiencing numbness on her left side. Her fathers grandmother diagnosed with MS at age 24.