Thinking and memory problems that can occur after cancer treatment are referred to as chemo brain (chemo fog, chemotherapy-related cognitive impairment or cognitive dysfunction). Though chemo brain is a widely used term, it is misleading. It is unlikely that chemotherapy is the only cause of concentration and memory problems in cancer patients.

It is clear that the memory problems commonly called chemo brain can be a frustrating and devastating side effect of cancer and its treatment. To understand this condition more completely, it is necessary to study it further.



Signs and symptoms of chemo brain may include:

  • Being disorganized and confused,
  • Difficulty concentrating, finding the right word,
  • Difficulty learning new skills and multitasking,
  • Fatigue,
  • Feeling of mental fogginess,
  • Short attention span,
  • Short-term memory problems,
  • Taking longer than usual to complete routine tasks,
  • Trouble with verbal memory, such as remembering a conversation,
  • Trouble with visual memory, such as recalling an image or list of words,



It is not clear what causes signs and symptoms of memory problems in cancer survivors. Cancer-related causes could include cancer treatments, complications of cancer treatment, and emotional reactions to cancer diagnosis and treatment.


Risk factors

Factors that may increase the risk of memory problems in cancer survivors include:

  • Brain cancer,
  • Chemotherapy given directly to the central nervous system,
  • Chemotherapy combined with whole-brain radiation,
  • Higher doses of chemotherapy or radiation,
  • Radiation therapy to the brain,
  • Younger age at time of cancer diagnosis and treatment.



The severity and duration of the symptoms described as chemo brain differ from person to person. Some cancer survivors may return to work, but find that tasks take extra concentration or time. Others will be unable to return to work.

In rare cases, people with memory and concentration problems are unable to work and must file for disability benefits.



No cure has been identified against chemo brain because it is not clear what causes chemo brain. In most cases, cancer-related memory problems are temporary and treatment focuses on coping with symptoms.

There is no standard treatment for cancer-related memory problems. Symptoms and severity differ from person to person and it may be necessary to develop an individualized approach to coping with it.

Cancer and cancer treatment can lead to other conditions, such as anemia, depression, sleep problems and early menopause, which can contribute to memory problems. Controlling these other factors may make it easier to cope with these symptoms.

A neuropsychologist, who specializes in diagnosing and treating conditions that affect memory and thinking, can design a plan to help the patient cope with chemo brain symptoms.

No medications have been approved to treat chemo brain. But medications approved for other conditions may be considered.



Researchers have been looking into how to prevent and treat cancer related thought and memory problems. It is still too early to know how well these work but they include:

  • Erythropoietin, this drug may help by raising haemoglobin levels,
  • Aspirin, which works as a mild blood thinning drug,
  • Methylphenidate, a type of stimulant for chronic fatigue syndrome, daytime drowsiness and attention deficit disorder.

Erythropoientin or aspirin treatment may help maintain or increase blood flow to the brain cells and so increase their oxygen supply. Understanding more the causes of chemo brain will help doctors to find ways of preventing and treating it.