Do not read this to understand MS on a medical level, it is probably incorrect on a dozen points. It is only a layman's decription in order to understand what's going on and how to deal with it.
Some basics
The cause of MS is fairly well understood. It's an auto-immune disease, where the body's own T-cells damage the sheaths of the nerves (the myelin sheath). The damage is irreversible, there is no way to regenerate the sheath, although stem cell research looks like it could eventually provide a therapy that eliminates the ill effects. What triggers this attack is less well understood. It only happens in some people. There is an inherited risk but it is not a hereditory syndrome, though the risk is higher for Caucasian people than non-Caucasians, and the incidence is higher for populations in Northern Europe than elsewhere, and higher among females than among males. Onset is typically between ages 20-50.That's all - as far as I understand - uncontroversial, but also not very helpful. You can't avoid it by living a healthy life and you can't escape it once it manifests.
To understand the consequences of MS, one has to understand a few things about neurology, which is complex far beyond any simple mechanical level. I've found a few analogies are helpful.
Timing
First, a nerve is not one cable that transmits a meningful self-contained message. Rather, it's a bundle of very simple signal paths, like a binary symbol - on or off. Actually it's probably truer to say it's a numerical value (an intensity) but it helps the think of it as a binary (on or off). Imagine you're watching like a film, showing the result of rolling a dice. Accounting for all the different ways the dice could fall, you'd need to monitor nine positions: the positions of a "six", when it falls so the lines of the six are horizontal or verical, plus the central position (for "one", "three" and "five"). We're glossing over that the dice may not always land in a well defined spot or orientation, it's actually not important.You're watching - your brain is watching - a sequence of dice outcomes, each outcome represented as a set of signals in those nine spots. You can quickly learn what each combination of signals means. Only the spot in the middle: that's a "one". That middle one and the corners: that's "five". Two diagonal corners: "two". And so on. That's what your brain does. It sees that sequence and you experience it as those interpretations, although it is relayed to your brain as separate signals for each spot.
You're watching a series and it is meaningful to you once you've learned to interpret it. This is what you do as a kid, you learn to make sense of the world. Now imagine the timing of those positions being relayed to your brain changed. Perhaps you learned to interpret the signals using a system where the top row took 2 milliseconds, the rest of the signals too 3 milliseconds except the centre point which took 6. Now imagine you're watching one dice roll every millisecond. Cool, it can still be done, the rules are just a little more complex.
Now here comes MS: the damage to the myelin sheath changes the transmit speeds of the nerve. Some of the signals are delayed, say by 2 milliseconds, some by 3, some by 4, a few not at all. All the patterns you learned to look for are now irrelevant. You have to learn them anew. This is not impossible, but frustrating and slow. It's exactly like learning to walk again, which, incidently, is exactly what I just did.
This damage also affects a bunch of nerves that are used for stuff you willfully control but don't really have a conscious image of how you control them - you can't feel the muscle that controls focus of the lens in your eye for instance. You just think of what you want to focus on and, presto, the eye does the rest. If you have to relearn that, good luck trying to do it consciously. Relearning to walk up the stairs is easy by comparison, you know at some level which movements you need to repeat. Not so with the eye.
Chemistry and hydraulics
That's one side of the effects of MS - the easy side. The other side I've settled on to decribe the effects involves a bit of chemistry, or perhaps cars. If there's a leak on the brake system of a car (the old hydraulic sort, not some new-fangled electrical one), oil leaks out when you apply the brakes. The more you brake, the more leaks out, and the less efficient the system becomes. This describes what happens in a nerve with a damaged myelin sheath. The transmittor leaks out, making the signal weaker and weaker, and it leaks out when you use that nerve. Once enough has leaked out, the nerve becomes more or less useless - it feels like an overpowering fatigue that is nothing like what you feel after doing physical activity (muscle work), it feels more like the mental fatigue you feel after taking a math test. And that's exactly what it is, mental fatigue driven by mental activity - neurological activity.The name "multiple sclerosis" means "many scars", and relates to those damaged myelin sheaths - those scars are both what changes the timing of the signals and what leaks the transmittor substance.
Training and medicine
There is no cure for MS. There are modification drugs, which are meant to stop the flares of the disease, so you don't get new scars, but that's all. You can train in order to relearn some of the signal patterns, and there are some attempts at preventing some of the leakage from the scars. There are drugs and recommendations that are aimed at a higher level, such as giving the body better ability to cope with the situation, like eating fish at least so and so many times a week (the reason is more complex than that).So that's what I'm doing: training, practising walking and moving, looking for a medicine that will let me handle the fatigue.
