Hi guys,
I had both courses of Lemtrada if anyone has any questions. Took it when my RRMS became highly active in its early teenage years, and was never treated with anything apart from LDN that I self funded for a decade as NHS did not offer anything.
I believe Lem to be a highly successful treatment as it halted my MS full stop. It leaves me tired as it wipes quite a lot of blood cells, but I would recommend it to anyone and have no regrets. Fatigue is more like permanent weakness or passivity, (I call it “laziness”!) and not gluey up and down powerless short tempered MS fatigue. The side effects are exactly as mentioned elsewhere, but all manageable with medications, and they seem to last during or shortly after the infusions (up to a week for me). The raised skin patches look diabolical to the extreme, but do not itch-more burn. The steroid high is fun as well, as a very high dose plus more is administered if Lem failing. (Me!) I got Cushing syndrome as a result but it settled soon, but not completely. The weakest period seems to be four months afterwards when infections seem to be ongoing, so I recommend just staying put, and accepting it as a part of the treatment. Nothing that sofa surfing and virtual imprisonment can’t prevent. 
Lem and/or steroids caused serious skin thinning and 20-30% hair loss that recovered by month 6, as well as problems with gums, tooth enamel, digestive problems, reoccuring cold sores for few months etc. This is all very subjective to me, and I was worn out from a decade of attacks, am in my mid forties, and was half dead from highly active MS, so please see it as such. (Couldn’t chew, swallow, talk, remember my phone number, and hardly moved either limb. I now go to gym presenting as quite “normal”) First dose was tough and apart from being covered in cold sweat from Lem pain&etc, I also had a run through of every single attack I ever had, and I had tons. The flare ups just roll several in few hours when being infused-as if MS cells try to attack an old lesion before exploding from LEM. The experience is unnerving, but when prepared for it, quite manageable as time restricted to infusion+settling couple of days afterwards. Second dose follows a similar pattern, but is substantially milder as killing only MS affected cells that managed to hide in lymph cells during the first dose. I was hugely relieved when the second dose went easily, as it was at least 95% easier to cope with for me. I have no health problems that surfaced as a result, but need to go back to a specialist hospital monthly for years to come, to have blood works and see MS Nurse who does a monthly check. Tedious but nice to be followed up so thoroughly. To cut the long story short: Lem works, everyone with highly active MS should go on it now, as it is very dangerous both in short and long run, and I personally would not risk it if having a benign or slow MS of one attack a year or two. Basically it is fit for young gamblers who just got diagnosed and want to kill MS and face the infusion problems if they arise, or for seriously affected folk with relatively old and misbehaving MS, that have not much to lose, but still have a chance of preserving mobility. I was in the second group, and feel to have done the right decision for me. Please note that I worked full time with average MS for ten years, so only last two were seriously hideous-possibly because I was overworked and tried to play normality-I don’t want to scare any freshmen with my descriptions. Please ask if wanting to know more, but note I do not frequent this forum, so unlikely to be posting many future comments. Going for Lem was actually being planned as my last kick back, as I got tired of accommodating MS. I was going to kill it being inside of my blood, even if I went with it, so the decision was very very easy for me.
Best to all 
Lala (minus blood cells where MS used to live)