Eighty-five percent of patients with MS having Relapsing Remitting MS (RRMS), but what is a "relapse?" If you are confused by the words "relapse," "exacerbation" or "attack," you are not alone. This is confusing for patients, carepartners, primary and ER doctors and surprisingly even for neurologists.
RRMS means that a person has neurologic signs and symptoms lasting for longer than 24 hours that are separated in time and space (meaning it is not always the same symptom - so for instance it could be one-sided weakness at one point and eye pain and loss of vision at another) and not explained by another diagnosis (such as stroke). MS relapses or exacerbations or attacks (all of these terms are used to mean the same thing) usually last for a lot longer than 24 hours though, and usually last for weeks to months before improving. Sometimes doctors use steroids to make these symptoms get better faster, but remember that steroids can have side effects and are not thought to change the course of MS.
So what are the fast symptoms that you have, that seem to come and go within seconds to minutes? We call these "paroxysmal" symptoms and they do not necessarily mean that your MS is getting worse, but they can still be annoying (and even painful) - like trigeminal neuralgia (sharp shooting pains in your face). Sometimes you may notice that some of your older MS symptoms seem to come back when you are tired or overheated. This also does not mean that you are having an MS relapse, but rather it could be Uhtoff's phenomenon, where heat can uncover older MS symptoms.
The good news is that the most recent clinical trials suggests that RRMS patients on disease modifying drugs have an average of one relapse only every three years. This means that we are getting better at controlling relapses and preventing them (and even when they happen, it is thought that they are less severe when you are on medication than when you are not). The problem is that half the time patients with RRMS are left with some disability after a relapse and do not get back totally to their old baseline. This is different from progressive MS, where there is an accumulation of disability (like more trouble walking) even without or in between relapses (if there are any). Once again, the good news is that doctors and scientists are working hard to develop medications to help slow down progression.
So, how do you know when a symptom is actually a new relapse? A good rule is that if a symptom is severed or new or lasts for more than a day, then you should call up your neurologist and consider being evaluated by them. Remember, everyone is different and individual, so work in partnership with your neurologist in a plan of what to do with new symptoms.