Cerebral atrophy is a shrinking of the brain. It can be caused by stroke or brain trauma, various forms of dementia, cerebral palsy, Huntington's disease, MS, infections, epilepsy, or a number of other diseases. I have read a recent study which found that Cerebral Atrophy can be a result of extended drinking and the degree of atrophy depends of the duration of the drinking problem. There is a condition called alcholic associated dementia. It has been found that the atrophy can decrease after a period of abstinence, unlike the atrophy from Alz. You can do a web search on Alchohol Associated Dementia to read about it.
Is there a way you can visit with her to see what is going on? Or somebody close by that you would trust their opinoin? I have a feeling you might find more than you know is there. My Mom enjoys reading. She picks up a book or magazine, reads until she is interrupted, lays it down and never looks at it again. She doesn't remember what she has read previously. She his her inabilities for several years. She blamed the little flubs that we caught on sombody else, especially Dad, or on the fact that she was Dad's caregiver. When we almost caught on she explained to us she was depressed... she had also convinced her doctor of the same. We found out she had been on antidepressants for a while. When we looked deeper we found the burned pots stuck in the back of the food cabinets. We found thing she had ordered and not paid for because she didn't remember ordering them. Bills were unpaid and other paid repeatedly. Medication was being taken improperly. All the while she was telling us that she was fine... just a little depressed. Then the ladies in her bridge club said she couldn't remember the cards she had played, and the neighbors told us horror tales. Nothing substitues for being a snoop.
Get her permission for you to talk to her doctor. See what he says. Ask him to give her a mini mental and see how she does. Find out what medications she is on. If you know any friends or neighbors near her talk to them. If you can go visit her for a week.... do so. From experience I can tell you... if you expect something is amiss, it probably is!!
There are many reason for cognitive decline and if you are experiencing such you need to make sure your doctor is aware. I had a scare a few years ago. With a grandmother, several great aunts and aunts, a mom and a dad with dementia I truly believed I was headed down that path... until I found out that it was a side effect of the statin lipator that I was taking.... Now I have my brain back...at least for a while
Hope this has been of some help. Hang around a while and let us know what you find out. I hate you needed to be here but glad you are here!! I will keep you and your Mom in my thoughts and prayers and hope to hear from you again soon.