Neurological Disorders Forum - When should I be concerned?

blood tests showed- elevated sed rates, elevated ANA, elevated enzymes indicating muscle damage
ruled out MS, Lupus, GBS, MG, swallow test results indicate that there are some anomalies
Psychologist ruled out conversions.

negative MRI and a positive EMG

I have been combating this for 3 years... symptoms came about 6 months after septicemia
Doctor says (motor neuron disease) but does not know what kind.

Symptoms:
weak muscles, left hand is barely functioning , I can no longer write, difficulties with balance, I now use a powered wheel chair, I have difficulties with eating, I am progressively getting worse.
from what I was once able to do, to where I am now, is a significant difference. .I was very active in many different ways, now i cannot speak effectively. I use an onscreen keyboard for most of my communications. My legs and arms have gotten skinny.

There is not much pain, only when I have muscle contractures.

Is there some rare disease that they cannot find? What kind of Motor Neuron Disease do I have?

When I fist started showing symptom, it was thought perhaps that there was an autoimmune type disease . I have been to a Rheumatologist to rule out arthritis and also to an orthpedist to rule out other problems regarding the loss of range of motion that is displayed in other areas of my limbs.
It was also suggested that I have more than 1 illness.

At this point, I have only had the 2 EMGs. My reflexes are in tact,although grossly exaggerated in my severely effected limbs. Characteristics of this did have a modest start with only my toes being effected and a bit of awkwardness to where I am now. If there is hope to stop this, I would like to but if there is none,I would at least want to have more of a concrete answer so that I may plan ahead.
In the beginning, I was told that it was some kind of autoimmune disease and I was never informed of the type. In the beginning of fall 2007, I was told that it was not and that I was more likely to be afflicted with a motor neuron disease but once again, not told what kind.
I see the changes in my own body and I really want to be able to go back to the way things used to be. I am only 40 years old, and a new grandmother, I want to fix this.
If I can not, then I would like to know what it is so that I can move forward with understanding, a possible cure, and mostly, a chance to grieve.

P.S- I find myself working hard at breathing. I can still do it but it feels like I am not doing it well and like it is a workout. When I adjust myself or exert myself, I have a harder time catching my breath. I am experiencing a sensation like holding my breath to long. Can it really change that quickly and when should I go to my internal medicine doctor?