well I am certainly not a doctor nor am I an expert, but MS symptoms come from demyelination of the CNS. When this occurs in MS, there is an abnormal immune response; the body attacts its own myelin, the myelin is damaged. The immune response cools, at this point, there may be some re-myelinating. When there is re-myelination, there is some healing. This can cause some variation in symptom severity, however this is a slow process. This would not allow for say, blurred vision that comes one day and leaves the next. It also does not allow for vertigo for an hour or so.
There is a certain ebb and flow to residual symptoms. These still tend to be permanent symptoms but they can worsen with fatigue, heat, colds, stress, allergies or whatever. I almost never have nerve pain upon waking but by 4 pm I have icy-hot feet everyday. I can have increases in my ever-present vertigo. If I subject myself to heat for over 30 minutes or so can drive my vertigo way up. My vertigo and balance can become much worse if I am stressed or anxious.
MS causes permanent lesions. Very small lesions may re-myelinate enough to no longer show on an MRI. I have never had this happen although I am sure others have experienced this. None of my lesions have disappeared. Most people with MS just continue to add to their lesion load. Since MS lesions tend to be permanent, so do their symptons.
I have a friend with MS. He woke one day to very poor vision in one eye. This progressed to no vision over the course of a few days. He had no sight in this eye for about 4 days. Then it slowly got better with some cooling and re-myelinating that occurs after a flare. He can see out of that eye but has very poor color vision. This now is the permanent residual symptom. It does not come and go.
Obviously if you have read an article or articles stating that MS symptoms come and go then by all means perhaps they do. I have read no such article. My symptoms do not come and go. That is my best attempt at "unbaffling" you. MS is an extremely poorly understood disease. You may have to decide for yourself what is "right."
There are many, many MS mimics. Please don't think I am telling you that you DON'T have MS. However there are many other diseases that cause the same symptoms. That is why it is so hard to get a diagnoses. Some literally go for years before getting a diagnosis.
http://www.msfocus.org/publication_articleDetails.php?id=15