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Brain Fog and Cognitive Effects

WC3 Member Posts: 658

I didn't see a recent thread for this so I thought I would create one. When I first started hormone therapy I was placed on Tamoxifen. I started it just a few months after chemotherapy, and between the two I experienced pretty thick brain fog in some respects. I'm on Lupron and Anastrozole now and my mind is significantly clearer but I still have moments where I struggle for words or can't think of a name or where something has left my mind.

Recently someone who is not aware of my situation accused me of being inattentive because I was unable to recall the specifics of a situation from a few months ago, when in reality, I had been paying attention and the details had just escaped me. I haven't addressed it with him yet but I feel like it's a no win situation as far as my reputation goes because "I was paying attention. I just forgot," doesn't really sound any better than "Sorry, I'll pay attention next time." I end up looking either irresponsible or rude when I am neither.



  • waves2stars
    waves2stars Member Posts: 95

    Sounds like a the real problem is mansplaining! I’m sorry you are still experiencing cognitive issues from your treatments.

  • threetree
    threetree Member Posts: 982

    WC3 - Thanks for starting this thread. I agree that the negative cognitive side effects of these drugs are a serious problem and yet I rarely see anyone on here talk about it. I think it should have it's own category and threads, etc. Medical people don't really talk about either. I take Letrozole and the brain fog, forgetfulness, etc. is overwhelming. I've read that it messes with our "working memories" and that is the sort of thing you described re "paying attention". You can pay attention, but it doesn't stick. I find myself forgetting all sorts of things; names, words, things that were told to me not all that long ago. I have started telling people that I take a prescription that causes a lot of cognitive problems and that I am sorry I don't always come through. Even with an explanation, I still wind up looking unreliable or inattentive, etc. as in your case, so I don't know if there is a solution. I don't think it's just a problem with men who don't understand, as suggested above, I've had plenty of women express their frustration with my current disabilities (that is what it is; disabling).

    I also find that I get a "tired brain" a lot too. Just like the cancer treatment fatigue that our bodies experience, I'm convinced that my brain experiences it too. Reading in depth is also a problem; reading technical or complex material of any nature is pretty much a no go for me these days. too.

    I would love to see if more people on these AI's read and contribute to this thread, as this is a real under acknowledged problem with these AI's. I'll be following along here for sure.

  • I'm on tamoxifen now. I experience everything described. Can't remember names, have trouble recalling things. I even forget if I've just done something-like putting my son's lunch box in his backpack. I couldn't remember if I did that. And when I looked it was there. No recollection doing it. As a preschool teacher, I really struggled with the kids names. And even after I knew them I still blank sometimes or call them the wrong name. It's embarrassing to me. My co teacher is kind and the kids are very forgiving. But it is frustrating

  • debal
    debal Member Posts: 600

    Hi all. " You can pay attention but it doesn't stick" perfect description Three tree. I find I need to read and re-read sentences when getting through a book. Now I need it to be quiet when reading- no background TV, music etc otherwise I can't focus. I can still multitask when needed -the line used to be blurred now its clear cut when my brain is full and I'm glad I recognize it.

    With that said lol I'm a nurse ( I'm sure you are thinking stay away from that hospital lol) and I still feel at the top of my game. It's bizarre. My critical thinking skills are still there and I'm still seen as a strong resource. I continue to get positive feedback from managers and coworkers. After 38 years I guess some things are second nature. New computer updates and change in documentation can send me into a tizzy but I've always been that way

    It's outside of work when I notice the brain fog. How can I be ok at work and so forgetful at home? Maybe it is tired brain. Is it the chemo, or Ai, or both? I mentioned all this to my breast surgeon who also happens to be a coworker and friend. She said it makes sense to be more comfortable at work because it is routine in a sense. She strongly suggested I step out of my comfort zone and challenge my brain with puzzles etc. It needs to be something new to retrain the brain.

    I'm just sharing my personal experience and I do not regret the path I chose. I'm not complaining. I will continue to take this pill because I'm more scared of recurrence. Of course no guarantees. I think when we choose the path that is right for us it provides just a little less worry.

    Thanks for starting this thread. I would like to hear from those that had brain fog etc and have now completed 5/10 years therapy. Did brain fog stay the same, improve?

  • debal
    debal Member Posts: 600

    monarch, remembering names of all the kids in your class? Oh my that would be tough! You are in such a busy environment with many distractions too. I noticed you are not all that long post chemo. The first year of BC is a whirlwind. As for your son's lunch- years ago my friend picked up her 2nd grader -he gets in the car and hands her a package of raw chicken. She packed that in his backpack instead of his lunch! And she did not go thru BC treatment. Hang in there

  • waves2stars
    waves2stars Member Posts: 95

    I hope I didn’t come across as minimizing cognitive defects. I have them myself but am hoping it has more to do with the stress in the last six months than the tamoxifen. I would hate to be called out on it publicly and be unable to explain it. I’m sorry if I seems insensitive!

  • beaverntx
    beaverntx Member Posts: 2,962

    The only good news about Tamoxifen induced brain fog that I can offer is that it comes and goes. Most of the SEs for me are cyclical and brain fog is included! I have found that most of the time when I really need to concentrate I have to avoid distractions when I used to be able to work through them. Looking forward to reaching the 5 year point.

  • VioletKali
    VioletKali Member Posts: 97

    Brain fog is real. I declined hormonal therapy, BUT my hormones have never recovered and I continue to have that "stuff" 7 years out.

  • rah2464
    rah2464 Member Posts: 1,192

    Yes the brain fog and nothing new sticking raising my hand here! I do still have my critical thinking skills but writing new information into a repository where it can be retrieved - not so much. I had been attending a local German language society school on Saturdays but have given it up because even with studying and practice I am not making sufficient headway. I feel the information is written somewhere but darn if my poor neurons can find it.

    I have a sister who swears by line dancing to reactivate the brain. Makes sense. I have recently begun playing the piano again in hopes that the coordination with my fingers and brain might spark something.

  • katyblu
    katyblu Member Posts: 176

    Good morning ladies! I experienced a lot of brain fog with chemo and tamoxifen for my initial diagnosis. I would forget the names of co-workers and constantly mixed up my Bs and Ps when typing or trying to spell. The fog slowly diminished but never went away. Now I'm taking arimidex and ibrance and the brain fog is back. My concentration ability has decreased. It's hard for me to focus sometimes. And my vocabulary has taken a hit, I forget easy words and it both embarrasses me and frustrates me. I've started working on different brain puzzles to help exercise my brain so I hope that helps in the long run. Wishing all you ladies better brain function in the future!

  • debal
    debal Member Posts: 600

    hi Rah. Your sister may be on to something. It makes perfect sense. Line dancing would be a physical activity that requires concentration. I may try to watch urban cowboy again!

  • threetree
    threetree Member Posts: 982

    Do all these brain games, puzzles, learning dance steps, etc. really help? Is there any evidence of that. other than anecdotal? Not that I dismiss anecdotes and people's stories at all, just wondering. The problems are due to the low estrogen, and doing all the games and dancing in the world isn't going to give you more estrogen.

    There is a fairly recent study out there somewhere in which they tested the cognitive effects of letrozole, I think, on rhesus monkeys or baboons or something (I hate reading about that stuff done to animals!) and the researchers concluded that the cognitive damage experienced by the poor test subjects was really something and that "we've got to find a better way"! I'll try to post the study if I can find it again.

  • threetree
    threetree Member Posts: 982

    Here is an article that links to the study I mentioned above (it was marmosets, not rhesus monkeys or baboons), and a direct link to the study. It is working memory that is especially affected, due to the estrogen deprivation, and that is why we can listen and read, etc., but have nothing really register for the long haul.

    This study was very small and maybe the only of it's kind, but it is interesting that these marmosets showed the same kinds of side effects, including cognitive, that we have all been talking about. Apparently marmoset brains are particularly similar to human ones regarding the kinds of things that AI's effect.

    Just found another study that suggests that AI's cause cognitive dysfunction:

  • salamandra
    salamandra Member Posts: 677

    I'm not a scientist but my understanding from supporting loved ones go through treatment for brain related stuff of different kinds, and my own various treatment journeys, is that the brain is really pretty amazing and when one pathway is closed, it can sometimes compensate in other ways.

    So I don't think that the brain activities would cure the lack of estrogen so much as help the brain develop compensatory strengths that can - in practical terms - offset the harm from the loss of estrogen.

    I guess not completely unlike doing physical therapy for the parts around an injured ankle or the parts upstream that have to carry a heavier load to compensate. It's not that it fixes the harm, but it still overall helps the whole body work better. That's how I conceptualize it anyway.

    Presumably it could also work for other mammals if we understood enough about how to provide those kinds of therapy and measure the impact on their functional health

  • lillyishere
    lillyishere Member Posts: 748

    To every doctor I have been to, dermatologist, GYN, dentist, etc. and I tell them I use letrozole, they switch the whole conversation on I'm sorry but estrogen is very important and we can't do much if you are in anti-estrogen treatment.

    In my case, I do feel the difference since I went to surgical menopause and started letrozole that I changed very quickly, muscle mass and memory went down the hill. I feel AI aged me 20 years! I am trying to keep up with healthy food and yoga but it is nowhere to where I was.

  • threetree
    threetree Member Posts: 982

    Salamandra - Really good points about the brain creating different pathways. Thanks for offering up that idea. I know what you're talking about.

    LillyIsHere - My dentist didn't really know anything about letrozole, but he told me he had recently been to a continuing ed program where a local oral surgeon he has referred me to in the past, gave a presentation on AI's and dental work, but the focus was primarily on dental work itself of course. (The current thinking apparently is that jaw necrosis is seen more frequently in those taking AI's for cancer than in those taking the drug for other reasons - thought that was an interesting highlight of what the dentist told me.) Most of the other providers I see for anything don't really know anything about these AI's or their effect on our bodies - especially that they effect everything in our bodies! They just seem to think it is under the purview of the oncologist and leave it at that.

  • debal
    debal Member Posts: 600

    Ineresting links to the studies. Very well said Salamandra. I feel pretty much on the same cognitive level as a 90 year old woman at times. I'm definitely sharper in the early mornings and more brain tired in the evenings. The thought enters my mind to take a break from arimidex just to see how it would feel. That would make restarting that much more difficult so I will just keep plugging along.

  • Honeybunch1
    Honeybunch1 Member Posts: 1

    I couldn't agree more that the cognitive effects of anti-recurrence meds are vastly underreported. I had no cognitive side effects during 3 and a half years on Tamoxifen, just leg cramps and wild hot and cold flashes (I learned late from a neurologist that cold flashes are a known thing!). Then my uterine lining became way too thick and I had to have a D&C and immediately stop Tamoxifen. So I started Letrozole. I was on it for three months before realizing that my cognitive function had gone completely, even comically haywire. I went from being in full possession of my wits to behaving as if I were descending into senility. (Senility differs from Alzheimer's, btw.) I picked up a pen to write the word "spiral" and found later that I had instead written "resound" (and I'm a writer!). What finally woke me up to what was happening was when I couldn't find my dog's food for the day. For 8 years, I'd been preparing three bowls for her in the a.m., then putting two of them in the fridge for later. When I went to get the second bowl that afternoon, I could not find it. Nowhere in the fridge, not in the freezer, not in kitchen cabinets, not in a drawer. I finally discovered it, by chance, in the breadbox. That's when I finally took another look at the possible side effects. Confusion doesn't appear on Medline (the NIH website-) but does appear far down on the Mayo Clinic list. Even farther down is "being forgetful." Thankfully, as soon as I quit taking it, my wits returned.

    I then switched to Exemestane, which caused terrible depression (which I again did not realize for a full three months. Just started Anastrozole and less than 24 hours later experienced the dizziness that the label on the bottle warns of. I'm hoping this goes away, because the only remaining choice is a hysterectomy. Without a uterus, I can safely return to my old frenemy Tamoxifen.

    Hope this helps someone.

  • threetree
    threetree Member Posts: 982

    Honeybunch - You did help someone, as I found your comments very relevant and informative. I can relate to a lot of what you've said and it helps me feel like I'm not alone in this (because I usually do). I'm sure your post will help many others also. Thank you.

  • moderators
    moderators Posts: 6,970

    Honeybunch, we are really happy that you're here sharing your experience. We're sorry for all you are going through, but as Threetree said, it helps as you are not alone. Medicating

  • fairchild
    fairchild Member Posts: 138

    Folks, I so understand what you're going through! I finished chemo in 2018 and stupidly came back to work as a professor right afterwards.... only to find I couldn't call up the terms I needed when I was lecturing! Now, several years out from chemo, I still struggle with many aspects of my job, especially those that involve multitasking, concentration, sequencing, and shifting sets. My oncologist has put me on ADHD meds, which have helped, but the difficulties are enough that I've scaled down my research and am preparing to retire in 2 years at 67. My heart's just not in it anymore.....

  • threetree
    threetree Member Posts: 982

    Fairchild - Boy, do I ever hear you! I'm work in social services and am not a professor, but I have all of the same kinds of problems you've described, ever since starting Letrozole. I've wondered about something like Ritalin, but I haven't asked about it anywhere. It's interesting that you have found that the ADHD meds don't completely help enough to keep working. I am struggling to do my job, and in my case I have court deadlines that need to be met among many other things, and I'm finding that I just can't "pull it all together" to get all of the things I need to do, done. Each time I have to write a report, it's like I have to learn my job and all the lingo, etc. all over again. Can't focus, can't concentrate, or get organized. I feel like I'm letting my colleagues and our clients down, along with myself. I too am starting to wind down, as I feel I have no real choice but to quit my job and retire. I am in the process of scaling back and looking at quitting altogether. I will be 69 tomorrow, but up until Letrozole that I started taking in January of 2020, felt no need or desire to quit at all. I enjoy what I do, can do most of it on my own time, and a lot of it from home (not at home, although some of that too). I feel like Letrozole is actually putting an end to my work life when I would otherwise continue to enjoy several more years of working.

  • WC3
    WC3 Member Posts: 658


    I didn't take any offence to your reply to my post or think you were being insensitive at all. I have definately been mansplained to before! This though I can say was not an instance of that as he didn't explain anything to me. He just accused me of being inattentive. Though I sensed he thought I was being critical of him at one point and I do wonder if he would have felt that way if I were a man. It's impossible to say in this instance though because I've only just met him and I haven't seen him interact with men. Anyway all of that is a different topic for a different time.

  • paddlinlou
    paddlinlou Member Posts: 8

    I am happy to see this post! I too am having memory issues. I've been on Letrazole for 3 yrs and have recently changed to Anastrazole due to intense bone and joint pain. Hope the switch will improve my memory as well.

  • murfy
    murfy Member Posts: 250

    I used to teach Endocrinology to med students until I retired 10 yrs ago. I talked about all of estrogen's effects, including in the brain. Estrogen is important in the formation of new synapses in the brain. This is why there is so much aromatase there, necessary for estrogen synthesis. Working memory involves the formation of new synapses. The good news is 'fuzzy brain' means that the aromatase inhibitor is working in general; the bad news is our brains aren't getting all the estrogen they need to function at 100%. However, all should return to normal when finally off the AI. Also, there is good evidence that exercise can lessen the effects of loss of estrogen in the brain. Hope this helps.

  • debal
    debal Member Posts: 600

    Hi Murphy, good stuff. Definitely helps. Having a sign that the drug is working makes taking the pill a little easier.

    I like learning about all of the AIs just in case I switch. Since you taught endocrinology I hope you don't mind a silly question. I always hear AIs are "equal" but do you think there is a benefit to exemestane over the other 2 given its a steroidal aromatase inhibitor and the others are not? Initially I was told to pick one and without really thinking much I eliminated exemestane just because of the word steroid. Maybe I should have looked in to that one more after all. Just curious.

    It's always nice to see names of members from years past. I remember you as we went through chemo at the same time. Hope you are doing well! Thanks for your post

  • sunshinegal
    sunshinegal Member Posts: 67

    I've been having definite cognitive lapses - forgetting words and intermittent brain fog. However, I'm not sure how much is down to the stress of the pandemic vs. letrozole. I've only been on letrozole since Sept 1 and I've been having (mild) cognitive problems for at least a year and a half. At minimum, letrozole isn't *improving* anything...

  • gradystubs2022
    gradystubs2022 Member Posts: 10

    Yes the AI ages you terribly....the brain fog, the joint pains and issues, chronic insomnia EVERY night and I've been on anti-depressants for years and this had made it considerably worse. I'm on a vicious cycle of not sleeping, which makes me tired all the time and its hard to exercise. I work full time and they've just dumped a huge workload that will go on for the next two years and am not sure I can handle it without my head spinning on my shoulders. I'm 62 and aging alone so at the moment I'm not sure I will make 5 years with all the se's

  • Murfy, great information, thank you!

    As someone who is 2 1/2 years in on an AI and recently have really noticed the brain fog, I appreciate knowing that all should return to normal when I'm done with the AI.

  • lillyishere
    lillyishere Member Posts: 748

    Murfy, thank you. If we make it to the finish line, we will end up as a bunch of smart old ladies hanging out in this forum. :D