Chemo-Related Cognitive Changes

Have you ever been walking down the street and recognized someone but could not for the life of you recall that person's name? If you said yes, you are likely one of many who have too many things to do and not enough time to do them, and your memory loss is due to overwork and stress.

For cancer survivors, it may be more than that. It may represent the all too common "chemo brain," an unfortunate side effect of chemotherapy that is only now being more understood. Most often, this cognitive change is mild and short lived. However, it can be more severe, impacting daily life and causing significant upset to survivors.

For some, symptoms may include memory lapses, difficulty focusing, recall memory loss, word loss, and/or disorganization. They may be mild or more severe, affecting several facets of daily life, including work and personal commitments. Unfortunately, there are no preventive measures that reduce the risk of these cognitive changes.

It is not completely clear what causes these cognitive changes, but there are several factors during treatment, such as:

• Malignancy
• Polypharmacy
• Low blood count
• Sleep disturbances
• Infections
• Fatigue
• Hormonal changes
• Co-morbid illnesses
• Nutritional deficits
• Age
• Depression
• Stress or other psychological issues

Some studies evaluating images have noted that the area of the brain responsible for memory, planning, etc. are actually smaller after receiving chemotherapy. These studies demonstrated that cognitive changes were seen more frequently in those who received high-dose chemotherapy (i.e., stem cell/marrow transplantation). However, a 2009 study noted that some of the symptoms had started before stem cell transplant and actually improved over the subsequent 18 months. Other studies noted cognitive changes two years after treatment that improved four years after the completion of therapy.

A 2011 study evaluated stem cell transplant patients who received high-dose chemo and immunosuppressive drugs and found that, even though some "thinking" problems had improved after one year, 40 percent of patients continued to experience mild brain difficulties five years after the completion of therapy. There was improvement in all tested areas, but there were still deficits in hand speed and dexterity and word recall.

It has also been identified that, in breast cancer patients who have received chemo, there is a lower resting brain activity up to five to 10 years after the completion of treatment versus those who have not received chemotherapy. It was also seen that the chemo-treated survivors needed to call on and utilize larger areas of the brain for memory testing versus women who did not receive chemotherapy.

A more recent study completed in 2012 evaluated women after breast cancer surgery and noted that one in four had word skill deficit and one in seven had memory deficit before any other form of treatment. It was noted that these women did report higher levels of stress. However, the surgery itself, drugs used in surgery, and other factors may have played a role.

Many women who I see report mild cognitive changes such as "I can never find my keys" or "I just have trouble getting words out." As a provider, it is important not to completely disregard this as "chemo brain." In some high-risk women, it may be indicative of brain metastasis or early onset Alzheimer's/dementia.

During many routine visits, as well as survivorship visits, I address memory changes. Yes, in most, it is related to outside stressors or "chemo brain." However, I have had the unfortunate few who have been found to have metastatic brain disease requiring treatment, which stresses the importance of a thorough evaluation. At that time, brain imaging and evaluation with a neurologist may be warranted.

What are your experiences with chemo brain or metastatic brain disease? How are your patients evaluated further?