Hypoxia and memory impairment from infancy to adolescence

The brain uses a tremendous amount of oxygen in order to function. When the amount of oxygen that is available to the brain is reduced, we know that a vulnerable memory structure, called the hippocampus, can become damaged.  When the hippocampus is damaged, it can impact on a child’s ability to memorise things. Although they might be able to understand new words or information, they simply cannot remember that new information later on.

We call this type of memory disorder developmental amnesia. Not only can it affect a child’s schooling, daily routines and their self-esteem, it can be very difficult for their parents too.

Over the last few years, our understanding of memory and the brain has improved. We now know that some infants may be at risk of developing memory problems or even developmental amnesia as a result of hypoxia. These may include babies who have serious heart problems or breathing difficulties that need to be treated very early in life.

We know from our ongoing study, Hypoxia and memory impairment in children, that older children who have experienced a lack of oxygen (hypoxia) can sometimes develop serious memory problems without any obvious signs of brain damage. This has therefore encouraged us to look at the at-risk infant group with heart or lung defects, to see if we can identify early warning markers to predict if the infant may go on to develop memory problems as they grow and develop.

From early infancy, children are constantly learning and developing, achieving various milestones as they grow. There are various cognitive and behavioural indicators that help medical professionals (and later educational professionals) assess how the child is developing.

In this study we are interested in how some infants’ milestones are changed or delayed after hypoxia. By using MRI (magnetic resonance imaging) scans, which take pictures of the infant’s brain at the early (8-16 weeks) and later stages of infancy and early childhood (18-36 months), we are hoping to monitor changes in the key structures of the brain and, in conjunction with standard tests, determine how their memory and cognitive ability might develop.

By comparing findings from a healthy group of babies with those who have been exposed to hypoxia, we hope to identify brain and behaviour markers that may serve as an early indicator of memory problems that may emerge later in childhood. It is hoped that with an early diagnosis and the right support and intervention, we can minimise any difficulty that the child may experience.

We have funding from the Medical Research Council and have just started this study, which is set to run for another four years.