Most people with multiple sclerosis (MS) — except those with primary-progressive MS — experience relapses (also called attacks, exacerbations, or flares) during the early phases of the disease.
What is an MS relapse?
A relapse, which is defined as the appearance of new symptoms or the aggravation of old ones, lasts at least 24 hours (more often a few weeks) and is associated with inflammation and demyelination in the brain or spinal cord.
Folks often call them “exasperations,” either by accident or on purpose, and for good reason: They never come at a good time, they generally produce one kind of discomfort or another, and more often than not they interfere with everyday life at least to some degree.
The first key point in the relapse definition is that the symptoms you experience during a relapse are the outward signs of disease activity in your brain or spinal cord. The second key point is that the episode needs to last for at least a day to be considered the real thing.
These points are important because, as you’ve probably noticed, MS symptoms frequently act up for short periods of time — minutes, hours, or maybe even a day or two.
But most of these relapse wannabes aren’t caused by disease activity in the CNS, which means they aren’t true relapses. When symptoms act up for reasons other the disease itself, they’re called pseudoexacerbations.
Recognize the MS relapse wannabe
Symptoms can act up for a variety of reasons — most of which are in response to a temporary increase in your body temperature instead of any underlying disease activity.
Even a half-degree elevation in your core body temperature can cause a pseudoexacerbation. For example, you may notice some discomfort in the following situations:
When you’re exercising in a hot environment or for prolonged periods of time
When you’re running a fever caused by a virus or some kind of infection — most commonly a urinary tract infection (UTI)
When the weather is hot or humid or both
If you experience a heat-related pseudoexacerbation, don’t panic — your MS isn’t progressing. The symptoms will gradually subside as your body temperature returns to normal. Keep in mind, though, that if your flu or urinary tract infection lasts several days, the pseudoexacerbation isn’t likely to simmer down until the fever is gone.
And it’s possible for an infection — which revs up your immune system — to cause a true relapse. So be sure to let your neurologist know if your symptoms don’t disappear.
You may also find that your symptoms act up when you’re particularly tired or stressed out. This reaction isn’t too surprising considering that most people (with MS or without) tend to feel crummy when they’re exhausted or under pressure. So, again, don’t panic — this blip in your symptoms doesn’t mean that your MS is getting worse. Chances are that you’ll begin feeling better after a good night’s rest or after a little fun and relaxation.
Know when to call the MS doctor
If your symptoms suddenly take a turn for the worse, or you experience a symptom that you’ve never had before, take a minute to think about what might be causing it. If you’re overheated, tired, or particularly stressed out, take a little time to chill out. If the situation doesn’t improve by the next day or so, it’s time to check in with your neurologist. Just remember: Virtually nothing that happens in MS is a dire emergency, so don’t feel that you have to rush to the ER or call the doctor at 2 a.m.
However, not every symptom that you experience will be related to MS. MS doesn’t protect you from other illnesses. Symptoms such as an abrupt onset of chest pain, shortness of breath, and a severe headache that is followed by weakness or difficulty speaking are examples of symptoms that do need immediate and emergency attention.
Because any kind of infection can cause MS symptoms to flare up, your doctor will probably first check to see if you have a UTI that may be causing the problem. UTIs are very common in MS, and they can aggravate other symptoms even before you’re aware of the bladder problem. After the UTI is treated, your other symptoms will quiet down.
Your doctor will also do a neurologic exam to look for anything that has changed significantly since your last exam. These findings, in combination with the information you provide about the changes in your symptoms, enable the doctor to determine whether you’re experiencing a true relapse.