Cognitive Dysfunction

Fight the mental fog from cancer treatment

Those being treated for cancer often feel like they can’t think clearly or they have trouble remembering details such as names, dates and telephone numbers. Many say they have memory lapses in the middle of tasks or conversations and have difficulty paying attention, and they have described the overall feeling as a “mental fog.” These symptoms all represent cognitive dysfunction, which has become popularly known as “chemo-brain” because of the original belief that it was a side effect of only chemotherapy. Research has shown that cognitive dysfunction related to cancer treatment is real, affecting attention, concentration, short-term memory, language skills, organizational ability and arithmetic skills. These problems are usually subtle but can be troublesome or frustrating.

Why does cognitive dysfunction occur?

The causes of cognitive dysfunction are not clearly understood, but it may be the result of damage to healthy cells from cancer treatment. Studies have shown that in some people the parts of the brain that deal with memory and planning are smaller after chemotherapy. In addition, cancer treatment can cause anemia and fatigue, both of which may also result in cognitive dysfunction, especially the ability to pay attention.

Who is most likely to be affected?

Although cognitive dysfunction has been most closely associated with chemotherapy, it can occur in people who receive other types of cancer treatment, such as immunotherapy (interferon or interleukin) or hormone therapy (antiestrogen drugs or androgen-deprivation therapy). People who take medications such as opioids (for pain), corticosteroids or drugs for nausea and vomiting may also have cognitive impairment as a side effect of these drugs.

When does cognitive dysfunction occur?

Cognitive dysfunction that is related to immunotherapy, chemotherapy, radiation therapy or hormone therapy can occur during treatment but often does not occur until months or years after the end of treatment. Cognitive dysfunction related to other medications usually occurs during the time the medications are taken and then go away when they are no longer taken. How long cognitive dysfunction lasts varies from person to person.

How is cognitive dysfunction managed?

Your doctor will evaluate you to see if cognitive dysfunction is being caused by something other than cancer treatment (such as anemia, unmanaged symptoms or a chemical imbalance in your blood). If another cause is found, your doctor can prescribe an appropriate treatment. If no underlying cause is found, your doctor or nurse will suggest simple measures to help you cope with the changes and improve your mental processing (Table 1).

Additional treatment options are available for cognitive dysfunction that gets worse or continues for many months after treatment. A drug commonly used to treat Alzheimer’s disease, donepezil hydrochloride (Aricept), has been effective for some people, as have stimulant drugs, such as methylphenidate (Ritalin). Occupational therapy or vocational rehabilitation may be helpful in improving the skills needed for daily living or for performing your job. Cognitive rehabilitation (also referred to as neuropsychologic rehabilitation) and cognitive training can help people improve their cognitive skills and learn ways to cope with cognitive deficits.

Table 1. Ways to cope day-to-day with cognitive dysfunction
Use a calendar or daily planner to keep all your important information in one place.
Write down all appointments, activities, medication schedules, important dates (birthdays and anniversaries), “to do” lists, phone numbers and addresses, names of movies you want to see and books you want to read.
Make a list each day of what needs to happen that day.
As you complete each task, draw a line through it and then go on to the next task.
Exercise your brain to strengthen your mental ability.
Do crossword puzzles or other word or number games, do jigsaw puzzles, play card games, play a musical instrument, learn a new hobby, learn a new language.
Get physical exercise to improve your mental alertness.
Walk, swim, bike ride, do aerobics, practice yoga or garden.
Establish healthy habits to help keep your mind and emotions healthy.
Get proper sleep, eat a balanced diet, use humor to cope with your forgetfulness.
Track memory and attention problems to help you determine when you are most affected.
Write down the time of day, the situation and any medications that are associated with cognitive problems.
Don’t try to multi-task.
Focus on one thing at a time.
Ask for support.
Tell friends and family that you’re having cognitive problems, ask people to repeat information or to write down new information (phone numbers, dates).

When should I talk to my doctor?

You should ask your doctor or nurse about the possibility of cognitive dysfunction with the treatment you’re receiving. It is also important to tell them when you first notice signs of cognitive dysfunction. Your doctor may want to do some blood studies to see if there is an underlying cause that can be corrected. Your doctor or nurse can also help you track the dysfunction to see if it gets worse and prescribe medication or rehabilitation, if necessary.