AFTER CANCER: NERVOUS SYSTEM.

What does it mean if my thinking is less clear than before my cancer?

Clouded thinking, frequent loss of train of thought, or difficulty in processing or remembering things is a common problem after cancer treatment. One young accountant found it hard to remember telephone numbers and calculate figures in his head. Working with numbers had formerly been his claim to fame. He was afraid that he had survived his cancer only to develop Alzheimer's disease.

Changes in memory and mental clarity are distressing. You may feel diminished self-esteem. Your awareness that you are different from the way you were is intensified. You may get anxious that something is seriously wrong with you.

On a practical level the mental changes affect the quality and efficiency of your work. This can cause increased stress at home and at work. Forgetting to pay the rent, pick up the children from camp, or take out the garbage on pickup day disrupts everyone's day. When you are aware of the mental changes, you may try to compensate by concentrating hard on everything you do, leaving extra time for "goofs," double-checking everything you do. Such efforts will help you perform normally but will drain your energy.

Tell your doctor if you notice changes in your memory or your ability to think clearly. The changes have many possible physical or emotional explanations. After evaluating you, your doctor may be able to reassure you that there is nothing seriously wrong and that you can expect the changes to resolve with time. This news will save you a lot of worry (about recurrent cancer, say, or swelling in the brain). If something needs medical attention, it will be attended to sooner rather than later.

Many medical and emotional changes after treatment can affect memory and cause clouded thinking. Any combination of the following may be playing a role:

• side effects of current medications

• aftereffects of cancer treatment

• aftereffects of your cancer (e.g., brain cancer)

• hormonal imbalance

• fatigue

•emotional stress, anxiety, or depression

What If My Balance Is Off?

A sense of imbalance or vertigo can be due to

• side effects of, or withdrawal of, medications

•aftereffects of cancer treatments

•aftereffects of your cancer (e.g., a tumor of the brain or ear)

• allergies