Neuro consultants use it to rule out other conditions to mimicking ms. It’s not that bad to be honest. One thing, is ask how experienced the doctor is in doing it. Make sure you lye flat for two hours. And drink plenty of full fat coke. That way you will be good to go in two hours. Drink the coke with a straw lying flat. And empty your bladder before procedure 
BE
Yeah good tip have loads of coke or black strong coffee before and after it really does work with the headache you might get. It’s all in the caffeine. With some PCT’s LP are usually done to look for oval banding in the cells of spinal fluid which is another part of MS Diagnoses. They also don’t really don’t like you driving after.