One side effect of chemotherapy that I never knew existed until I experienced it myself is chemobrain. I noticed after receiving a few doses that along with feeling physically sick I also felt different mentally. My mind was functioning slower as if the gears in my head were getting gummed up with molasses. The effect would be worse for about a week after each infusion and then gradually improve.
I have experienced chemobrain to varying degrees from all three of the chemotherapy regimens that I've received and from a special chemotherapy dose given during my biggest surgery. The main symptoms are:
- Impaired memory
- Difficulty concentrating
- Reduced intelligence
- Diminished creativity
- Lack of ambition
Failing memory is also a problem with relationships. Family and friends will call to check how I'm doing and I won't be able to remember what events we've already discussed or who has called recently. When presented with evidence I will vaguely recall the conversations but I often forget about events without reminders. I've probably done damage to my credit rating by forgetting that I had received bills in the mail and not getting around to paying them until I feel more clear-headed weeks later.
Beyond memory impairment I also suffer from other mental difficulties. My job is very mentally demanding (theoretical chemical engineering) and my personality is intellectual and introverted. But on days when chemobrain is bad I can barely manage to read and understand a newspaper. It's hard to concentrate on a subject or reason beyond a superficial extent. Television has become a good friend for giving me enough stimulation to keep me entertained without demanding much concentration or analysis.
I feel as though I lose twenty IQ points when I'm on a dose of chemotherapy. When I had a big surgery at the National Institutes of Health and was given a massive infusion of 5-fluorouracil I felt like I lost sixty IQ points. I could barely read and felt like an imbecile. Even many television shows were too challenging. The old game show The Price Is Right became the highlight of my days.
I don't know what the biological mechanism of chemobrain is. Maybe the chemotherapy drugs kill some brain cells along with the cancer, digestive, skin, and hair cells. Maybe it's not the drugs themselves but metabolic byproducts, the chemicals released during breakdown of cells, or changes in body chemistry resulting from the chemical load on the kidneys and liver.
Of course the chemotherapy drugs themselves aren't the only thing in my body during treatment. I take the antianxiety drug Ativan to reduce nausea and apprehension on infusion days and other times when I'm not feeling well. I also take the antianxiety/antidepression drug Paxil to manage associative nausea. I've read that anxiety is a big factor in the conversion of short-term memories to long-term storage. That's why people remember stressful events like the Challenger explosion or September 11th so clearly. Researchers have administered antianxiety drugs to prevent post-traumatic stress disorder in victims of war and accidents. I suspect that the antianxiety drugs that I take for nausea likewise interfere with long-term memory. It can be a blessing, since this aspect of chemobrain dims my memories of hospitalization and sick days.
I feel chemobrain most intensely for about a week after each infusion. It gradually fades away over the next couple weeks, and when I get a break from chemotherapy I start to feel really good as my mental abilities return. I often experience bouts of creativity and ambition as if I've been on vacation and just returned to an old problem with fresh eyes.
From talking to other cancer survivors I've learned that chemobrain can be a long-term problem. Many people experience memory impairment for three years after finishing chemotherapy or never recover completely. Being that my job and personality are so dependant on my mental abilities I was frightened that I would lose my intelligence permanently. But during my period of remission I felt at least as smart as I ever was -- maybe even smarter since I've gained wisdom and coping skills from my struggles. So although I still feel hampered by chemobrain I expect that I'll return to my usual self whenever I can get off of chemo.