Hi and welcome,
You asked "Would these issues show up in a brain MRI?"....theoretically if these different types of issues you've experienced were being caused by a neurological condition like MS, then usually the brain MRI wouldn't be clear of lesions or of normal findings for your age group. As Alex mentioned, MRI's done with MS protocol have smaller slices, usually 3mm vs the standard 5mm but it would still be unlikely that a standard MRI would completely miss everything or be clear of lesions...
You should keep in mind that whilst 'Nystagmus' is associated with neurological conditions including MS, there are many different types of Nystagmus and visual motor disturbances seen in many diseases of the nervous system, the vestibular system, the eyes, as well as in toxic and metabolic disorders......'gaze evoked Nystagmus' is actually the most common form of Nystagmus encountered in clinical practice, and is most often caused by medication eg sedatives, anticonvulsant drugs, central nervous system antidepressants, stimulants etc, is congenital, within normal ranges, misalignment, a visual convergence issue etc etc etc
It's understandably that MS would be in your thoughts because of your half sister but the issues you've mentioned have basically all occurred within the last 3-4 months with your legs and it bilateral ie both legs itching, knees down are tired, hot and heavy, worse after a work out etc...bilateral nerve issues are much more likely to be caused by a peripheral nervous system issue than MS, MS more commonly causes unilateral symptoms (note whilst bilateral is less commonly associated with MS it 'could' still be spinal cord lesion related), if you can please don't worry too much about MS at this stage because it honestly might have nothing to do with MS and is something else entirely unrelated.
Expect to have a better idea of what could be causing these issues after you've seen the neurologist and had a full neurological assessment and further testing....hang in there!
Hope that helps..........JJ
Thank you for the quick response! I've seen two family doctors whom both said MRI and then Nuerologist because I'm "clearly" having neurological signs. They had no idea why I would have the nystagmus without a brain injury, hence the referral I am assuming. Glad to hear about the smokey vision! Guess I'll keep my fingers crossed and try and be patient until I see the next doc.
Unless you are a family with MS it is not common to have MS if your sister has it. Some families have MS. It is not common. The statistics are low. What is more important than the MRI is a neurological exam. Any doctor including a family doctor can do it. It is reflexes and such. If you have neurological problems it would show up. Smokey eye is not a MS eye condition. Optic Neuritis and double vision are the two MS eye conditions. For the itching they can give you something like Neurotin for neurological pain or itching.
If you are worried you can see a MS Specialist. Only a Neurologist can diagnose MS. Neurologists specialize and all do not know about MS.
Oh and MRIs have to be done under MS protocol with and with out contrast. My first MRI was with contrast but not MS protocol which has more slices or pictures.
It can take along time to be diagnosed with MS. It took me two years. Neurologist like to follow you over time.
Alex