MS Symptoms: Why Do They Appear and Disappear?

Question: 
I've been diagnosed with PPMS, why do my symptoms wax and wane or disappear and others take their place?

Answer: 
Primary progressive MS is differentiated from relapsing remitting MS by two clinical features:
1. The slow temporal course of symptom development
2. The lack of significant improvement

Both relapsing remitting and primary progressive MS patients experience fleeting symptoms that come and go or symptoms that worsen with certain activities, illnesses or even the time of day; these signify neither a relapse nor progression. I have written previous blogs that explain the reason for these symptoms that come and go. Please refer to these blogs for an explanation.

Let’s look at each of the characteristics that differentiate relapsing remitting and progressive MS more closely...

Relapses are the acute or subacute development of new symptoms or worsening of old symptoms without improvement over hours to days usually with corresponding findings on examination by a neurologist; 80% of patients reach their worst deficits within 2 weeks and more than 90% within one month. At times the symptoms are so dramatic in onset that a relapse can be confused with a stroke.

Symptoms and findings develop very slowly in primary progressive MS. They also tend to wax and wan considerably at the beginning but the overall pattern is one of continued worsening. The most typical symptom is a slowly developing abnormality in the way a person walks. One typical story we hear from patients and families at the time they are first seen by a neurologist sounds something like this:

“I was always active until last year when I began to drag my right leg. Its been getting slowly worse and I finally agreed to see the doctor when I could no longer hide the problem and people at work were beginning to think I had a drinking problem.  I thought it was just a bad hip but my primary doctor could find nothing wrong with my hip. I’ve actually been a little concerned for at least two years or at least since our family reunion 2 years ago last summer; we had a game of touch football and I started to stumble and trip after playing for about an hour. I just figured this was due to the hot weather and deconditioning. After this I began to notice decreasing endurance with my morning jogs and began to trip or drag my right leg after a few miles; eventually I stopped running altogether about a year and half ago"
 
Contrast this description with a relapsing remitting MS description:
   
“When I woke up last monday my right leg felt heavy and my right foot was tingling. At first I thought the right leg was still asleep but the symptoms persisted. Later in the day I noticed that the numbness and tingling had moved up the right leg to about thigh level and I kept tripping over my right leg when I walked too fast. It seemed a little better with rest that evening. The next day when I got out of bed I stumbled to the bathroom because of my right leg weakness and imbalance and could barely walk without assistance. Of course, this is when I decided to come to the emergency department. The symptoms continued to get worse and spread to the left leg over the next few days. Once they determined I had MS they treated me with IV steroids. I noticed some improvement by the following day and was ready to return to work 4 weeks later. I felt almost completely normal within 3 months”

-Rip Kinkel, MD