Neuropathy and Cognitive Impairment

There used to be an anti-drug advertising campaign that showed an egg and said “This is your brain.” Then they cracked the egg into a frying pan where it sizzled while they said “This is your brain on drugs.” I was just sitting here thinking over the past four years and that ad campaign came to mind. It has nothing to do with the pain medications I take like Morphine and Dilaudid. Instead, what I’m referring to is the case of Chemo-Brain I suffered at the peak of my chemotherapy induced neuropathy.

I didn’t react very well to my chemotherapy. It started with Doxorubicin and then moved almost immediately to Velcade when the Doxorubicin sent me for a week in ICU the two times I was infused with it. I tolerated Velcade well enough in some regards, but suffered side effects off the charts with it. I took cycles for a year, and they had to be interrupted three times because of the peripheral neuropathy it created. But I also suffered fairly severe chemo-brain as well. For the most part, the usual appearance of chemo-brain is to give people what might be referred to as senior moments. Chemo-brain would cause you to be a little forgetful at times, not unlike what people endure when they smoke pot. Chemo-brain is a form of neuropathy and like peripheral neuropathy, is a gift from the temporary neurological damage caused by chemotherapy.

Some people, myself among them, suffer more severe symptoms, just as some people suffer it only mildly. (Some people don’t suffer from it at all.)  But I did, and the scope of the affliction wasn’t readily visible to me until viewed in hindsight. There were times that I couldn’t keep up with what was happening on television. People seemed to speak too quickly, and I might fail to understand the content and context of what I was watching. I could read an entire book, and then read it again a month or so later where I wouldn’t recognize having read it, but was mysteriously able to know what was going to happen next in the story. It would give me a strange sense of deja vu.

I was married while suffering chemo-brain, and it’s a sad fact that I have almost no memory of the ceremony. I can muster only brief flashes of images. As I look at photos taken during the nuptials, I register absolutely no recognition of the event; the pictures don’t trigger any memories. I don’t remember anything anyone might have said, or the way this or that person looked. A side effect of the side effect was mental exhaustion, which caused me to sleep as much as 18 hours a day. There were a few days I slept literally around the clock. Oddly, I do remember that for a while I was trying to hide my failure to comprehend conversations, often nodding as if I was in sync with the person speaking. When asked a question, I would reply with answers that turned the question around; “How do you think I feel about [it]?,  I might reply to whatever it was. Even as I did that, I didn’t recognize just how impaired I was.

Sure, I knew that I couldn’t stand because my feet hurt so badly. I knew I couldn’t hold a pen or use my keyboard, both from the neuropathic pain I suffered. But the impact on my cognitive abilities was invisible to me, and except for memory lapse issues, and even those close to me weren’t aware of the affectation.  As I look back now, after almost 18 months of remission, I am horrified by the impairment I can now recognize clearly in hindsight.

We have to remember how it is that chemotherapy works:  It targets the most active cells and so no one bats an eye when digestive problems occur while in treatment. We also know that some of what gets targeted is the central nervous system, and thus the neuropathy so commonly associated with our therapy. But it’s not common to make the jump to realize that we’re talking about the brain when we talk about neuropathy, –as if it’s name shouldn’t be a big clue for us. But the brain is affected by chemotherapy, and those who suffer badly from neuropathic manifestations in the limbs shouldn’t be too surprised that other areas of our brain might suffer as well. The brain itself doesn’t feel pain, so there is no  set of discomforts in the head that offers the physically felt discomfort. Neuropathy is difficult to treat because it has no pain path; it amounts to misfiring of the elements in the brain to which our nerves, the sensors of pain, are attached. It only follows that where erroneous brain activity occurs in one area, it’s bound to be occurring in others. After all, the chemicals of therapy are carried by the blood. That means the entire brain is getting dosed.

I have no medical research to validate my assertions, but I tend to believe that the peculiar and often frightening dreams that we experience during therapy may be the result of neuropathy. I also believe that some of the mood swings and disorientation evolve similarly. I don’t mean the agitation caused by steroids like Dexamethasone, instead I’m thinking of  perhaps more irrational fears or the sense of impending doom so many of us feel while in treatment. I hasten to say as well that I’m not talking about the production of psychosis or profound mental impairment. I don’t believe that happens. But I do believe that we do suffer effects like those I mention above, where the world seems to be moving a bit too fast, and the slight confusion that results. So don’t start speaking more loudly or over enunciating every syllable just because a patient forgets whether they took an aspirin. But it wouldn’t be wrong to try and tune up the empathy we have for ourselves as patients, or our charges as caregivers.

When a patient feels the discomfort of neuropathy, the old anti-drug advertisement should come to mind. This is your brain. And this is your brain on drugs.