The B-100 Complex you switched to has 5 times as much B-12 (500 mcgs) as a normal B-100 Complex (only 100 mcgs). This is why I recommend taking additional B-12 with a normal B-50 Complex which has half as much as a B-100 Complex.

It makes sense that the extra B-12 is making a difference.

People often discount the need to add B-12 to a B-50 Complex or even B-100 Complex. The injured brain needs much more B-12 than a healthy brain. Plus, many people do not absorb B-12 very well so they need to take extra.