It’s hard to witness cognitive issues in your spouse. I’m so sorry. Mine has Normal Pressure Hydrocephalus (NPH) which causes dementia, so I can sympathize with what you’re experiencing.
I am taking nilotinib (Tasigna) 300 mg twice a day as required as a participant in a clinical trial for newly diagnosed CML patients. I have been taking Tasigna now for 18 months with a few minor side effects, but brain fog not one of them. The Tasigna is working well for me.