Hello Curtrill,
I am not sure if you are still following your initial post but I wanted to tell you that I am in a very similar situation to you. I have seen a number of neurologists and have had one clean EMG and normal neuro exam despite stiffness, twitches, fasciculations and extreme fatigue. I recently (2 days ago) had another EMG and neuro exam at a neuromuscular clinic. The EMG showed the same things as your last one: polyphasics and re-innervation in both distal legs. The neuro exam was once again normal AND the ALS specialist saw the twitches on the EMG. I was scared that he was going to give me some terrible news since I could hear him say all those findings to the resident in the examination room. Ultimately he said: you do not have a muscular disease, I am not going to do a biopsy because there is no indication that I should do that, you do not have a terrible disease such as ALS. I didnt question him too much but he said that he would like to repeat an MRI of the lumbar region and that he believes that my symptoms are caused by a nerve irritation/injury. I had an mri done on my cervical and thoracic area and assessed by a top neurosurgeon. The only findings were mild spical cord degenerations where there was very slight pressure on the spnal cord in the cervical and a bit in the thoracic area. He also found a very small syrinx in the cervical area (8mm long and 1mm in diameter). All of those findinds were of questionnable clinical significance and could not be associated with my symptoms.
The conclusion was: wait and see, investigatge the lumbar region a bit more with another MRI.
Just one more comment on MRI's: there are many different resolutions/qualities for these. It is important that the MRIs that you had allowed to assess spinal stenosis. The typical MRI that looks for tumors is not detailed enough to make a clinical diagnosis of a syrinx or stenosis. Both of these can be a differential diagnosis for your symptoms.
To finish, my symptoms progression started about 2 years and 8 months ago...it is getting worse but very slowly. The neurologist said that my history, neuro exam and symptoms were pointing away from ALS. Even with a dirty EMG he said the chanes of ALS are 0%.
Hope that this information helps a bit, I believe that you and I should try to forget about ALS and get along with our lives...perhaps an hour or a day at a time at first. Once you convince yourself of something and start obsessing about it, it is difficult to live a normal life. Manage your symptoms best you can, I was told to take up swimming...did so yesterday.
Cheers, Matt21