By Dr. James W. Stark

People with multiple sclerosis can exhibit worsening symptoms for several reasons. Two of those reasons are an MS relapse, and a pseudo-relapse. These terms can be confusing, because physicians use them differently in medical settings than they are used in regular speech. 

Relapse 

Physicians use the term ‘relapse’ for new or worsened symptoms that are due to new inflammatory MS activity in the brain or spinal cord. In a true relapse, new symptoms usually manifest over a few hours or days, plateau over subsequent days to weeks, and then slowly improve over weeks to months. Steroids can often improve this kind of worsening quickly, but they are not always necessary. Additionally, the vast majority of the time, this kind of worsening is associated with a change in your MRI.

Pseudo-relapse

Physicians use the term 'pseudo-relapse' for worsened neurologic symptoms that are not due to new immune system activity or inflammation. Instead, these symptoms are the result of damage that has already occurred. This is very important because the treatment of pseudo-relapse is generally not IV steroids, but determining what could be affecting the body to bring out ‘old’ symptoms. 

There are a number of stressors that can affect the body and lead to pseudo-relapse. These include increased body temperature (from a fever, over-exercising, hot tub/sauna, etc.), infection even in the absence of fever (the flu, urinary tract, sinus, and skin infections…), trauma, surgery, new medications, other medical conditions (high blood sugar in diabetics, for example) and psychological stress. A pseudo-relapse is not associated with an active MS lesion on MRI.

Am I Experiencing a Relapse or Pseudo-relapse?

There are several clues that help differentiate between a relapse and pseudo-relapse. Occasionally, however, it can be difficult to distinguish and further ancillary testing, such as an MRI, is required.

• Timing

  Relapse: Symptoms often change steadily, without dramatic fluctuations. 

  Psuedo-relapse: If the worsened symptoms fluctuate, and especially if they resolve completely and then return, you may be experiencing a pseudo-relapse. This is one of the reasons that we rarely treat an MS relapse within 24 hours of symptom onset. Unlike a stroke, there is no evidence that rapid initiation of steroids is better, and we want to judge whether symptoms may improve on their own.

• Symptom Type

  Relapse: Your worsened symptoms are new to you. 

  Pseudo-relapse: Your symptoms include sudden worsening of spasticity and pain, as well as the recurrence of old symptoms. Generally, MS does not result in repeated inflammation in the exact same part of the brain, so it is unlikely that patients will experience another true relapse exactly the way their previous relapses presented.

• Localization

  Pseudo-relapse: Localization refers to the location of a lesion within the brain or spinal cord, based on the pattern of symptoms. Occasionally, neurologists can say for sure that there is no location in the central nervous system that a lesion could cause all of the current symptoms. This would suggest that another process (like infection, medication, or stress) may be going on, indicating a pseudo-relapse/generalized worsening, rather than a new, active MS lesion.

The Bottom Line

As neurologists, we use all of these points to help us evaluate what is going on when a patient feels worse. We rely on your history, especially the time course and pattern of symptoms, and use the laboratory testing and MRI additionally when needed. Remember, if your symptoms change, call the office at 212-265-8070.