I have been recently diagnosed with an AN. Frankly, I noticed less mental sharpness, more fatigue, headaches and constant ringing in the ears, but the biggest concern for me as a broadcaster was my inability to learn easily, recall words and speak fluidly. (The tumor is just shy of 2 cm and is pressing on the brain stem. I'm watching/waiting/researching because it seems there are no good outcomes and I do believe physicians should do no harm. So yes, I have noticed a decrease in cognitive ability, concentration, recall. Thankfully, I hear we use only 10 percent of our brains anyhow! Best to you.