Medal for baby brain injury treatment

Medal for baby brain injury treatment

Decades of research into understanding the impact and mechanisms of mild hypothermia treatment to reduce brain injury in newborn babies was recognised with the award of the Royal Society’s MacDiarmid Medal this week.

University of Auckland Professor of Paediatrics and Physiology, Professor Alistair Jan Gunn was awarded the MacDiarmid Medal for his research into using brain cooling to prevent brain injury in babies who experience low oxygen at birth.

The MacDiarmid Medal is for outstanding scientific research which demonstrates potential for human benefit. He developed “cooling cap” to treat babies with brain injury at birth, and led research into the best way the technique could be used for optimum outcomes.

Professor Gunn’s mother, the late Professor Tania Gunn was herself an eminent paediatrician and neonatologist, specialising in the care of newborn babies. Together they carried out a pioneering randomised, safety study of head cooling for babies in New Zealand in the late nineties.

His ongoing experimental studies provided the foundation for understanding how, when and for which babies, the cooling cap can successfully reduce brain damage.

“Professor Gunn has made a major contribution to perinatal physiology and neuroscience,” says the MacDiarmid Medal selection panel.

This study established that therapeutic cooling was feasible and safe even in very sick newly born babies, and that simple bedside tests could identify babies who might benefit from treatment within an hour of birth.

Professor Gunn then developed and led a major international multicentre trial involving 25 perinatal centres and 234 babies in New Zealand, United States, Canada and the United Kingdom. This trial demonstrated that cooling could improve survival without disability in all but the most severely affected babies.

Follow ups when the children were 78 years of age confirmed the results, as have eight subsequent published trials carried out by others around the world. Mild cooling (therapeutic hypothermia) is now the standard of care for treating babies with brain injury due to low oxygen levels worldwide.

“It’s only this year, 16 years after publication of our first study and nearly 10 years after the large trials, that mild cooling for reducing the impact of birth-related brain injuries on babies is now universally accepted in New Zealand and overseas,” says Professor Gunn. “Naturally I am delighted and honoured with this award.”

“We found that there was a delay of more than six hours between neonatal brain injury and the injury becoming irrevocable that offered the tantalizing possibility of treatment,” he says. “We have been able to refine the treatment technique to using a cooling cap to cool babies from the normal 37°C to 34.5°C, starting within the first six hours after birth and continuing treatment for three days. It is that first six hours that represents the critical time window to start treating this brain injury.”

“Our unique contribution was to show when to do it and for how long,” he says.

We can now say in retrospect, after all these trials that the benefits are real and highly consistent, no matter how you do it, as long as you cool the baby’s brain,” says Professor Gunn. “It is important to remember that while a little is good, more is not better. Mild cooling is clearly beneficial, but there is no evidence that deeper cooling is better.”

Professor Gunn and his team of researchers are now trying to find ways of further refining this technique.

“I’m the ‘king’ of negative studies,” he says. “We have tried a number of things that are not better than just cooling.There are still many potential add-on treatments. There is increasing evidence that natural anti-oxidants such as melatonin can be beneficial when combined with cooling, and we are continuing the search for the best possible combination,” he says

Of the process of neonatal brain injuries, Professor Gunn says, “We don’t know precisely how hypothermia works, but we think that hypothermia suppresses many of the deleterious processes that are set off by low oxygen levels.”, ”One of these is programmed cell death,” he says. “Cells are highly social. When they are injured, brain cells can trigger their own death and the death of other cells that are connected to them (like falling dominos) to help clean up the damage and improve the immediate chances of the organism to survive.”

“The brain injury is progressively amplified by this domino effect to a final step that finishes off the cells – it is this progression that is stopped by hypothermia,” says Professor Gunn. “Because there are many little steps, if we can suppress each step by a small amount, this can stop cell death from happening. In effect, cooling allows the cells to survive until their environment recovers and signals the cells to live.”

“From that point the injured brain can begin to restore its normal function,” says Professor Gunn. “It is very interesting that we found that cooling actually delayed recovery in the first four days and yet the babies had much less disability in the long-run after mild cooling.”

In partnership with international company Olympic Medical (USA), Professor Gunn developed a device for cooling a baby’s head, which is sold internationally.

Professor Gunn was made a Fellow of the Royal Society of New Zealand in 2009. He is internationally regarded as an expert in perinatal physiology and neuroscience.

His research has targeted major causes of death and disability in early childhood, including the prevention of cerebral palsy, the identification of compromised fetuses in labour and prevention of life threatening events in infancy.

ENDS

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