I had influenza followed by shingles in January 2013.......then one week later the twitching kicked off. I often wonder if BFS somehow started because my body just got run down from those viruses.......not only did I get influenza and shingles but I was sleeping poorly due to work and raising a young family.......plus I was squeezing in workouts when I should have been resting.
What threw a spanner in the works for me was the twitching settled into my left calf and foot which brought attention to the fact that my left toes won't raise off the ground (weakness) and my left calf was significantly thinner than my right. This resulted in neuro/doc visits followed by EMG/MRI and a diagnosis of spinal stenosis which has caused gradual decline in muscle bulk over the years in my left calf plus weakened my left toes (they don't raise off the ground but I can push them down OK).
i think what has happened in my case is a gradual decline over years (10+) in muscle bulk in my left leg due to the spinal stenosis (not uncommon, I never twitched back then though and the decline in muscle was so gradual it was not really noticed) and then unfortunately BFS started in my damaged nerves in Jan 2013 (which is when I had influenza + shingles and then the twitching started).
For the record I have twitched 24/7 for 17 months. All day everyday in my left calf....... never stops. I get them randomly in the right leg, arms, stomach and back but never for more than a day and usually only for a few hrs. I'm still working out with the same strength as normal though

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