Chemo brain: What it is and what you can do

[David Baxter PhD]

Suffering from “chemo brain”? There’s hope and things you can do​

by Jorg Dietrich, MD, PhD, Harvard Health Blog
Nov 20, 2019

Some of the most common symptoms experienced by cancer patients are memory problems, difficulties with multitasking, and reduced attention and concentration. Historically, cancer patients with these symptoms were often diagnosed with depression. Research over the past decade has revealed that many cancer patients experience such symptoms as a consequence of specific damage to the brain caused by either their tumor or their treatment.

While radiation to the brain has long been linked to causing cognitive difficulties, the effects of chemotherapy on brain structure and function have only recently been discovered. We now know that the majority of patients treated for cancer, including breast, lung, colon, and many other cancer types, experience difficulties with memory, multitasking, cognitive processing speed, attention, and concentration as a consequence of their treatment. The good news is that such symptoms may slowly improve over time in most patients.

There are treatment strategies to help patients recover more quickly
If you or someone you care for is having problems with memory or thinking following cancer treatment, it is important to undergo a comprehensive medical evaluation to rule out other conditions that can mimic certain side effects from chemotherapy. For example, endocrine disorders (such as thyroid abnormalities), vitamin deficiencies, sleep deprivation, or depression should all be ruled out (or treated), as these conditions can cause changes in memory and slowed thinking.

Extensive research over the past decade has identified how chemotherapy targets brain structure and function as an unwanted side effect of cancer therapy. Those efforts have also started to shed light on the mechanisms that enhance brain regeneration and expedite recovery from brain injury, previously thought to be impossible. While various therapeutic interventions currently remain in clinical testing, there are a number of lifestyle actions that have been found to be effective.

• Regular physical exercise. Cardiovascular exercise is one of the strongest drivers of brain repair after injury, stimulating the growth of new neurons, facilitating connections between brain cells, and enhancing overall cognitive resilience.
• Sufficient restorative sleep. Chronic sleep deprivation damages brain cells, prevents brain regeneration, causes daytime fatigue, and reduces cognitive function. Poor sleep also impairs the basic mechanism that eliminates toxic waste in the brain — a process that primarily happens during sleep. Simple behavioral changes to improve sleep hygiene include avoiding neurostimulants prior to bedtime (coffee, chocolate, beverages with high sugar content, etc.), and minimizing exposure to electronic devices in your bedroom. Meditation and various relaxation techniques can also be helpful to improve sleep.
• Good nutrition. A diet rich in antioxidants can be helpful in minimizing cancer therapy-related damage to brain cells and unwanted cognitive side effects from cancer therapy. Therefore, enriching your diet with fruits and vegetables, along with weight loss (if you are overweight or obese), are highly recommended strategies. While a natural supply of antioxidants and vitamins from food is best, some people who are unable to maintain a well-balanced diet may benefit from multivitamin supplementation.
• Engaging in positive and stress-reducing activities. Brain plasticity and nervous system regeneration can be enhanced when all senses are activated, particularly through activities that lead to new experiences and sensations (“environmental enrichment”). Engaging in new activities, learning a novel skill, or traveling can be of tremendous value. In addition, many patients find that engaging in spiritual practices can have a positive effect on healing.

Certain medications may enhance brain function and minimize cognitive symptoms
Medications such as neurostimulants and anti-aging drugs may be used in conjunction with lifestyle interventions to improve memory and cognition after cancer treatments. Speak with your doctor about these options.

New research suggests there may be a connection between the immune system, the bone marrow, and the brain, highlighting new avenues for future pharmacological and biological therapies that may enhance brain function after injury and delay the process of brain aging.

Cancer survivorship programs at many hospitals may offer help
A thorough neurological evaluation can be helpful in identifying areas of brain functioning that can be improved with specialized neurocognitive rehabilitation programs. Many patients benefit from this type of rehab as part of their cancer treatment.

Collectively, while symptoms of brain dysfunction are common in cancer patients, there are several interventions that can be considered to help with recovery and enhance healing. Research in this area remains in its infancy, but the curtain has been lifted. There are promising pharmacological and nonpharmacological therapeutic interventions on the horizon, and there are many lifestyle changes you can start today.

Resources

• Neural correlates of chemotherapy-related cognitive impairment. Cortex, May 2014.
• Assessment and management of cognitive changes in patients with cancer. Cancer, June 15, 2019.
• Pharmacologic management of cognitive impairment induced by cancer therapy. Lancet Oncology, February 2019.
• Sleep drives metabolite clearance from the adult brain. Science, October 18, 2013.
• Bone marrow drives central nervous system regeneration after radiation injury. The Journal of Clinical Investigation, June 1, 2018.