1 - Only The Previous MS Course Has Predictive Value
Like Fog, Neurologist who supervised the VA study developed a numerical disability score. MSers in the study were questioned and examined at five year intervals after their first symptoms.
Many factors were analyzed in the hope of discovering which ones might be predictive of later disability.
Of all the factors examined only one was important: the disability score at the fifth year. Subjects who had minimal disability at the end of five years continued on a Benign course.
Those with severe disability at five years continued to have severe and progressive disability for the rest of their lives.
This result is similar to Fog's. The difference is that Fog recognized the possibility of both acceleration and deceleration of progression.
These two studies indicate that if you are in the first year or so of the illness, you do not yet have enough information to make an accurate prediction.
They also demonstrate that if you are a senior MSer, you may use your experience. How much disability do you have now? How much did you have several years ago?
Consider the specific things you can no longer do, as well as the general course of the illness. Then look ahead a few years to estimate your own prognosis.
p351
2 - Symptoms Have No Predicitive Value
Doctors and patients worry unnecessarily about the frequency of attacks in early years and about peak severity of individual attacks.
If bowels and bladder or if BrainStem structures are involved, we shake our heads in dismay.
The VA's study showed that the degree of disability during an attack, the frequency of
attacks and specific symptoms during attacks, are of no importance in the long term prediction of disability scores.
Therefore if you are caught in the midst of an attack that seems never to end and if you have previously experienced good remissions after other exacerbations, take courage.
From that experience you can predict eventual remission this time too, knowing that only the progress of your baseline disability determines the prognosis.
3 - A Definite Prognosis For MS Symptoms
It is cold comfort to the MSer caught in a seemingly endless attack, to know that disability progresses independently of each and every attack.
At that moment there are much more important questions: How long will this attack last? How permanent are these symptoms? Can someone predict the eventual outcome of this attack?
p352
There is no specific answer for an individual attack, but statistical information may be useful. The VA's study asked: What is the prognosis of individual symptoms that have been present for two years or less?
After considering many factors, he found that only the duration of a symptom determined the statistical chance of its disappearance:
- If a symptom has been present for only a week, there is an 85% chance that it will go away.
- If it has been present for a month, there is a 38% chance of disappearance.
- Symptoms present for two years or more are probably permanent.
p353
These statistics parallel the daily experience of MSers. They have "bad days" when a leg refuses to walk properly or fatigue turns into exhaustion. On such a day the MSer can look to tomorrow with fair assurance that it will be better.
MSers usually do not call the doctor to report an exacerbation untill a new symptom has
persisted for a week or more, and is accompanied by other symptoms that indicate this is not merely a "bad week".
This hesitation may be an unwillingness to admit to another exacerbaation. However, it
is more likely the result of past experience with symptoms that went away on their own.
4 - Optic Neuritis Is Not A Sure Sign Of MS
Many patients with Optic Neuritis have been told that they have a 30 - 50% chance of getting MS. The VA's study demonstrated the risk is less.
Army personnel who developed only Optic Neuritis while on active duty were included in this study. Excluded were those who developed Optic Neuritis and other Neurological symptoms and those who developed a second bout of Optic Neuritis within a few weeks of the first.
Optic Neuritis, associated with other Neurological symptoms and repeated Optic Neuritis, are common early symptoms of MS.
After 12 to 18 years of observation, only 12% of the study group had developed Clinically Definite Multiple Sclerosis.
By projecting their data into the future, the authors expected that a maximum of 19% of the patients with isolated Optic Neuritis would develop MS.
The significance and even the basic nature of Optic Neuritis continues to be controversial. Two brief articles outline the issues. Each has an extensive bibliography to lead you further into the literature.
The VA's study was an enormous and comprehensive examination, of the natural history of MS. I have presented only those parts that deal with prognosis.
If you wish to read the rest of the VA study, your librarian can help you find other articles in the series.