It's a tricky one for Chris.
August 2010 he was having some problems with waking with burning sensations in his hands and I don't believe this was ALS. He had been a maniac digging up the huge vege garden and I suspected this was his problem and got him to go to a physio. Where ALS comes in is that the physio said then - you have muscle wastage in your shoulders. The physio fixed the problem with the burning sensation in his hands and it never returned. I would massage his shoulders and he would say they never used to feel like this! We were a new relationship, not quite a year, so I would shrug as I hadn't felt his shoulders before they had been like this. At that point zero clinical weakness or fasciculations. But later we have certainly wondered as once his arms started to atrophy I noticed the muscles felt exactly like his shoulders had back in 2010.
No real symptoms of anything wrong until August 2011 he had a bad flu, and after it was gone he kept doing this weird little throat cough, which I now know were tiny laryngospasms.
End of May 2012 was when he noticed he couldn't whistle anymore, had jaw clonus and then started slurring and having trouble drinking water. It was minimal however at this point, and took about 3 months til it was always obvious to everyone.
Diagnosis May 2013, we started seeing doctors at my insistence concerned with his speech getting worse in October 2012.
Flew free on his new wings April 2014.
I never can quite figure what to say about 'length of time', but I know that you don't have muscle 'wastage' without a cause.
My opinion - it was trying to take hold of him from sometime in 2010, but it succeeded in 2012.
Depends on how you calculate - he was gone 11 months after diagnosis, but 4 years after first hints at something wrong was noticed.
I'm forever glad we never suspected anything was wrong until until early 2013, because we lived life like the happiest newly wed maniacs you can imagine and I wouldn't be robbed of that time for anything!