I’m sure almost everyone reading this knows someone who is currently being, or has been, treated for cancer using chemotherapy. There are terrible side effects that can occur during treatment that can include nausea, vomiting, fatigue, sores, weight changes, and mood changes. What you may not know, are some of the effects that chemotherapy can have on the patient even after it is over. “Chemobrain” is the cognitive impairment that effects up to one third of cancer patients after chemotherapy is finished. This is a relatively new thing that doctors decided to research because patients were complaining about it. It is still scientifically debated whether this is a real side effect of chemotherapy or not, though many patients would argue that it is. Symptoms of “chemobrain” include visual and verbal memory loss (causing issues recalling conversations), attention deficit (causing issues paying attention to tasks), decline in processing speed, and trouble remembering words.
Serotonin is related to depression as well as cognitive function and can be significantly impacted by chemotherapy. In the model rats who received chemotherapy, scientists found a 42% decline in dopamine release and a 55% decline in serotonin release. Tests have only been done in model species such as rats, but these rats show that some biochemical markers of “chemobrain” include higher levels of hydrogen peroxide in the brain, and impaired release and uptake of neurotransmitters dopamine and serotonin. Higher levels of hydrogen peroxide in the brain could be potentially dangerous because it is a reactive oxygen and could cause issues with cognition. The neurotransmitter, dopamine, is present in many different parts of the brain, like the striatum. The striatum receives inputs from all over the brain, filtering unwanted inputs and amplifying wanted inputs. These inputs get translated into actions. So, decreases in dopamine could possibly affect cognition.
A possible preventative treatment for declining cognition due to chemotherapy includes KU-32. KU-32 works by inducing heat shock response, protecting cells and possibly counteracting the damaging effects of hydrogen peroxide. In rats, it has been found to prevent cognitive decline caused by chemotherapy, possibly by preventing increases in hydrogen peroxide production in the brain. This drug is still very new and in the preliminary steps of research, but it is a good step forward in figuring out a way to prevent cognitive decline in chemotherapy patients. Patients already go through so many difficult things during their treatment, they do not need to continue to suffer afterwards, too.
Posted by Jordan Milone (C)