Very interesting thread topic, Marg! Although the fatigue and muscle pain suck, brain fog is the worst. The brain fog really frustrates me like nothing else. I get the urge to kick or punch something to let out my anger when I am under the "fog". Nobody seems to understand but when I try to explain to others I compare it to not getting any sleep and being "brain fried" the next day. My brain feels 5X slower. But what is rather odd is that the fog comes and goes and is more intense and less intense at random days and times. Does any one have a better simile or metaphor to describe the cognitive impairment we experience?