Can you show us a picture anyway? Reddish brown edges are not unusual. There may be nothing wrong at all.

Attaching the best photo I have. This sprout has had several layers of leaves removed already.

Well it isn't the usual natural discolouration. That said I would still eat them - but I'm not fussy.

My guess is aphid damage. You should see tell tale signs they were there as they leave behind grey/blue residue.
I think they'll be fine to eat.

-Mark

I agree -- aphids are a chronic problem for me with B sprouts. Insecticidal soap doesn't get into the crevices where they hide, so I depend more on hoverflies and other natural predators. Good reason to keep flowers blooming well into fall.