Learning and memory skills depend on the brain’s ability to process information and apply knowledge. This ability is called neurocognition. It includes language, memory, concentration, and ability to grasp new concepts. These skills are applicable in education, on the playground, and in the workplace.
More than half of children treated for acute lymphoblastic leukemia (ALL) do well and go on to lead normal lives. However, some children experience neurocognitive changes, such as learning difficulties, during and after treatment.
Symptoms of neurocognitive changes
Symptoms include problems such as:
- slow processing speed. For example, a child may have trouble keeping up in the classroom or take longer to complete tasks. Their behaviour may be interpreted as a lack of motivation, effort, or memory. But it may be because they need more time to process information.
- difficulty organizing work and getting it done on time
- problems with reading or reading comprehension
- difficulty understanding math concepts, remembering math facts, and working with columns and graphs
- problems with motor skills: These can include difficulty with handwriting, tying shoes, or riding a bike. A child may also have problems coordinating what they see with an appropriate motor response. For example, they may experience problems with copying text, kicking a soccer ball, or throwing a ball into a basket.
- attention difficulties, causing problems focusing for long periods of time. A child can become easily distracted.
- short-term memory loss
When do neurocognitive effects develop?
These problems emerge over a period of years after your child finishes treatment. Understanding the neurocognitive effects will prepare you and your child to manage any potential learning difficulties that may develop over time.
Factors that increase the risk of developing neurocognitive problems
Generally, children who receive radiation therapy to the brain are at a greater risk of developing neurocognitive problems than those who receive only chemotherapy.
Radiation therapy
There was a dramatic increase in survival rates of children with ALL in the early 1960s due to improved treatment. Doctors began using cranial (brain) radiation therapy (CRT) to target leukemic cells in the central nervous system (CNS). Despite the effectiveness of this treatment for saving lives, research showed that some of these children developed neurocognitive problems in the years after completing their treatment.
If your child was considered high-risk at diagnosis, they may have received radiation therapy (in addition to chemotherapy) as part of their treatment.
Chemotherapy medicines
Although less severe, chemotherapy also has an impact on neurocognition. When your child starts treatment, they may take steroids called prednisone and dexamethasone. While they are effective in treatment for leukemia, these drugs may also penetrate the part of the brain that affects memory. This is called the hippocampus. Consequently, some children may have trouble with memory.
When methotrexate is used in high doses to kill cancer cells in the brain, some children may develop attention and other neurocognitive problems. Younger children and girls tend to be more sensitive to the neurocognitive effects of these drugs.
Chemotherapy and radiation may change the structure of the largest part of the brain, the cerebrum. These changes can happen to the part of the brain that contains many nerve fibers, called white matter. Changes in the white matter affect overall IQ, attention, memory, and visual-motor skills.
Relapse
Children who relapse with leukemic cells in the central nervous system (CNS) require further treatment targeted to the brain. As a result of needing further CNS therapy, these children are at higher risk of experiencing more challenging learning problems.
Age and sex
The brains of very young children are still growing and developing. Hence, young brains are more vulnerable to the effects of cancer treatment. For this reason, younger children who are treated with radiation are more likely to develop learning problems as they get older.
Research also shows that girls under the age of five are more sensitive to the effects of cancer therapy compared to boys, including problems with learning and memory. We do not know why girls are more prone to neurocognitive late effects. We may be able to answer such questions once we understand more about how ALL treatment affects brain structure and function. This is an area of active research.
What can you do to help?
Understand possible learning difficulties your child may experience
Talk to your child about any issues or frustrations they feel. The sooner you understand the potential late effects, the better prepared you will be to help your child access effective resources so they can get appropriate support for learning challenges in school. A neuropsychologist can help to identify learning and memory problems. They can also suggest useful support groups and appropriate ways you can help your child.
Have realistic expectations
In supporting your child’s future dreams and goals, it is important to balance their abilities with possible neurocognitive challenges. Encourage them to explore all possible activities and opportunities where they can use their abilities and skills in a fulfilling way.
Your child’s motivation to overcome any learning difficulty is an important factor in their success in achieving future goals. Present your child with a realistic set of choices and options. A positive attitude and motivation will make them more likely to succeed.
If your child is experiencing significant difficulties with learning or attention, it is important to discuss treatment options with your doctor.
Cognitive rehabilitation
This is type of therapy that teaches children specific skills and procedures to help them learn most efficiently. The therapist works with your child on tasks that improve memory, attention, reasoning, and organizing information. Various professionals may be trained to offer cognitive therapy, including neuropsychologists, speech and language pathologists, or occupational therapists.
Special education and tutoring
Some children can benefit from individual or small group teaching in the school setting or tutoring outside of school. Aside from getting help in specific academic subjects, small group learning can help teach organizational skills that can benefit your child in school and the workplace.