I am told older people do not come back well from general anaesthesia. I wonder if this process becomes less reversible in older brains? It is only implicitly d

I am told older people do not come back well from general anaesthesia. I wonder if this process becomes less reversible in older brains? It is only implicitly discussed as reversing, and they didn't discuss detectable differences between activity before and after, only the uniformity of activity during.