Cancer patients who undergo chemo/radiation treatment often talk about "Chemo brain." I've experienced it, but determining causality is tough. Is it due to the

Cancer patients who undergo chemo/radiation treatment often talk about "Chemo brain." I've experienced it, but determining causality is tough. Is it due to the stress of having cancer and all that entails? Is it due to the treatment itself? I have noticed that I'm not as cognitively sharp as I was prior to chemo, but I've also aged 15 years as well.