Concentration problems, overstimulation, reduced stress resistance, memory problems after chemotherapy

 

Research has been done on the long-term effects of chemotherapy on the brain and specific cognitive functions. In the study, 196 women were followed after chemotherapy for breast cancer.
The effect of chemotherapy can still be felt in the brain twenty years later. In 70% of people who had undergone chemotherapy, the complaints disappeared within a few months after the end of the treatment.
About 30% of people who had undergone chemotherapy mentioned complaints in the long term, namely that what used to be easy now requires effort.

 

Brain-related complaints that have been mentioned:

• concentration problems, attention problems
• memory problems
  in particular difficulty with short-term memory, retrieving information

• reduced stress resistance
• difficulty switching to another task
• chronic fatigue / brain fatigue, neurofatigue
• overstimulation, such as also occurs after brain injury

 

Other physical complaints that are mentioned:

• changes in smell and taste
  
• tinnitus
  
• problems with hearing
  
• damage to nerve pathways (neuropathy)
  
• organ damage to heart and kidneys
  
• changed fertility/infertility
  
• changes in sex life

 

After research into 196 women with chemotherapy after breast cancer, (small) differences were visible on scans in both white matter and gray matter in the brain. This can be made visible with MRI scan Diffusion Tensor Imaging.
Why not everyone has complaints is still being investigated.

The quality of white matter, which forms the connection between the different brain areas, appeared to be somewhat less in people who had received chemotherapy. The complaints were comparable to damage seen in the painter's disease OPS after exposure to chemical solvents.

 

Other complaints of reduced function of the nerve pathways can also affect the quality of life. Burning mouth and neuropathy are often mentioned as permanent consequences of chemotherapy. Neuropathy literally means disease of the nerve tissue. Increased feelings such as burning, pain and shooting pains, cold feeling, electric shocks, tingling, pricking, or itching. The reverse can also be the case if the nerve transmits fewer signals; reduced sensation in the skin, a numb or dull feeling.

 

Myelin damaged

A study led by Mark Noble of the University of Rochester Medical Center, New York, investigated the effect of a widely used anti-cancer drug 5-fluorouracil (5-FU) on mice. The study showed that the insulation layer of nerve tracts (myelin) in the corpus callosum became much thinner.

 

In particular, the oligodendrocytes, the cells that produce the insulation layer, myelin, were affected. Oliodendrocytes are part of a certain type of glial cell, the support cells that provide the nerve cell extensions.
Without this insulation layer, the speed of signal transmission is much lower and therefore the signal transmission is slower.
The corpus callosum connects the left and right hemispheres of the brain.
This study also showed that people had problems with retrieving memories, organizational skills and attention and concentration.

 

Neuropsychologist Christina Meyers, who worked with Mark Noble, discovered that 19 breast cancer patients already had cognitive problems before the chemotherapy was started.

This was probably caused by the cancer itself or by the stress of the diagnosis.

61% of people who had chemotherapy showed that their cognitive skills had declined immediately after treatment. A year later, half of these people still had complaints.

 

The brain areas

Complaints appeared to be related to the (dorsolateral)
prefrontal cortex (executive functions such as planning, making decisions, controlling impulses) and the (lateral) parietal lobe (attention, spatial thinking and memory functions) and the parahippocampal gyrus, the gyrus at the hippocampus or seahorse to which memory is related.
The research by the University of Rochester Medical Center, New York also showed that the corpus callosum is involved.
It appears that higher educated people experience more complaints because for them a small change can already have major consequences in daily life.

The mental effort they have to make for a task is much greater, which means that these people can sometimes no longer perform their work at their old level.

 

Hormone therapy and radiation

The blood-brain barrier protects the brain to some extent from cancer treatments, but brain cells are more sensitive than other body cells, so even tiny amounts of a drug that seeps through the blood-brain barrier can cause damage.

It turns out that it didn't really matter whether you had chemotherapy in pill form or by infusion, nor did it matter what type of chemo someone had. Hormone therapy and radiation also appear to have long-term cognitive effects.

 

No dementia, cognitive therapy may help

Researcher Mark Noble emphasizes that no one should turn down chemotherapy because they fear chemobrain. He says it's not the same as dementia and that lifestyle tips or cognitive therapy/rehabilitation may help a person.

 

Researchers are continuing to figure out which drugs can be given at the same time as chemotherapy to reduce the risk of chemobrain. Research from the University of Rochester shows that administering IGF-1, a growth factor, shows promise in animal studies.

 

Brain damage from surgery

Brain damage can also be caused by surgery on a tumor or by scar tissue.