Fatigue and numbness are very common MS symptoms, are you on a DMT? Sounds like you might be relapsing if those are new symptoms that you've not had before, contact your MS nurses and let them know ASAP. It might be that is the reason they have bought the MRI forward. Depending on the lesions that they see on the MRI, they will probably advise you to start on a DMT to stop the relapses, which ones they offer will depend on how much damage you have and how frequent your relapses are happening. Hope this helps

@natalieaf I can't work out how to reply directly to you, so hope this reaches you. My understanding of a relapse is a new symptom or problems with a different part of your body, so if your left arm went numb that would be a separate relapse. It's causes by a new lesion on your brain or spine, hence the need for the MRI to see what is going on. They might want to do an MRI with and without contrast, they inject some special dye into a vein in your arm and repeat the scan, which shows up active areas of inflammation and fresh damage, doesn't hurt, just extra time in the scanner. I suspect your MS has become active after a quiet period, if the symptoms are causing problems they can give you steroids, if not, you just wait it out and they should settle down after a few weeks. Sadly the damage in your brain or spine is more permanent so you can get those same symptoms in the future if you get ill, overtired etc. Best way of stopping the relapses and the damage is a DMT, huge range depending how active your MS is and how much damage they see in the MRI, can be tablets, self injectable or infusions in hospital. Normally once they have your MRI results they will call you in to discuss and offer you a choice of DMT. The MS trust website has some good info, and a DMT comparison tool which I found helpful. The MS society website is good too and you can phone and talk through your options with one of their volunteer nurses. Don't forget to ask on here, people here will help too. The decision isn't permanent, if the option you choose doesn't work for you, you can switch to a different one. While you are waiting for you MRI and the results, try not too worry too much, it's really hard but stress can trigger another relapse and you want as few as possible before you get on the DMT as it can stop future damage but not repair existing damage. Take care of yourself, I know it's a scary time but there are really effective DMTs available now, likely to stop future relapses.