Thanks for chiming in mrsD,

You are completely right about the effects of nitrous oxide on B12 and subsequent neurological problems which accompany B12 deficiency. Luckily I was aware of the nitrous-b12 relationship and did check my b12 levels shortly after the operation and they were normal (though I know that standards for adequate b12 vary from US to Eutope or Japan). I have continued supplementing my diet with b12 as part of general diet just to be safe, and my levels have been off the charts high for several months.

Thanks for your response! B12 deficiency is definitely something anyone (particularly those with vulnerable brains) should be aware of.