Many people with cancer experience memory changes—such as mild forgetfulness, an inability to concentrate on more than one task, or more severe memory loss—after undergoing chemotherapy or radiation treatments. In other cases, as in a person with a brain tumor, the cancer itself may cause memory changes. Surgical interventions, particularly for brain cancer, may also lead to memory loss.
Studies show that patients experience trouble with memory and language skills after chemotherapy. Scientists are searching for the exact cause, but they believe the chemotherapy agents may be associated with this side effect. The drugs are designed to attack cancer cells, but often kill healthy cells in the process. Researchers are studying whether chemotherapy agents may be damaging healthy brain cells. Others believe the cancer itself may be responsible for the memory changes.
Similarly, radiation therapy also may cause people with cancer to lose some mental abilities, including memory. Physicians use radiation waves to penetrate cancer cells and stop them from growing. During the process, the rays may damage some healthy tissue. The severity of damage depends on the dose and duration of the radiation treatments. In some cases, cells killed by radiation can form a tumor-like mass in the brain, which can lead to memory loss. Children who undergo radiation treatments for a brain tumor may have developmental delays later in life.
Other side effects of cancer, such as fatigue , pain, and depression , may lead to memory impairment as a person struggles to cope with cancer. Living with constant pain, for example, takes a great deal of energy and can cause a person to become more distracted than usual. Sometimes, especially in elderly patients, it can be difficult to tell if the memory changes are caused by an existing dementia or the cancer treatment.
Depending on the type and intensity of cancer treatment, memory difficulties may fade over time. Some people, however, will experience a permanent loss. Families can help by offering useful strategies, such as making lists of daily tasks, using a calendar or daily organizer, reducing stress, and encouraging the person to ask for help if disoriented.
Patients scheduled for radiation therapy should discuss their concerns about memory loss with their physician before the treatment begins. The radiologists may be able to control the dosage to minimize damage to healthy cells. For instance, many hospitals use a gamma knife for brain cancer treatment. The device allows radiation therapists to simultaneously attack a tumor with high-energy rays from several different angles. The gamma knife sends a concentrated dose to the tumor without damaging surrounding brain tissue.
Occupational therapists can assist people who find that cancer-related memory changes are interfering with their ability to work or perform normal activities. Many people learn helpful coping strategies from other cancer survivors by joining a support group. Since more damage occurs in younger patients, children who go through radiation therapy for brain tumors may need extra tutoring, or special education programs when they go to school.
Alternative and complementary therapies
Often, when physicians prescribe medication to ease a person's pain or depression, the patient's memory may improve as well. Researchers also are studying the ability of the herb gingko biloba to increase mental sharpness. Although it has not yet been proven to be completely effective, some people with memory loss find it helpful. Since gingko can cause circulatory problems, it is important to check with a doctor before taking it.
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Liu, Li, M.D. "OncoLink FAQ: Long-Term Complications of Whole Brain Radiation." OncoLink: University of Penn sylvania Cancer Center. 5 July 2001. 13 July 2001 <http://oncolink.upenn.edu/specialty/rad_onc/faq/faq_brainxrt.html>.
Melissa Knopper, M.S.