There are hopes growth hormone could help the recovery process after stroke or acquired brain injury. Tessa Hoffman speaks to one of the men pioneering this work, neurologist and neuroscientist Professor Michael Nilsson.
Your research just published in the journal Stroke uses an animal model to suggest that growth hormone can help to repair damage to the brain after a stroke. Can you talk a little more about this, and the work that preceded it?
We have studied the effects of growth hormone on recovery and protection after stroke for quite a while. We have had some suspicions over the years that a proportion of stroke patients are developing growth hormone deficiency. We have demonstrated that this happens after traumatic brain injuries and we are now in the middle of a similar study in stroke patients in Newcastle. Preliminary data indicates that maybe 20-40% of the cases might develop a deficiency. We have previously also in human material demonstrated that related hormone insulin growth factor-1 circulating in the blood stream after a stroke is linked to better recovery.
What is the mechanism by which GH is thought to facilitate repair in the brain?
In the elderly population the GH levels go down slowly over the years. It has previously been demonstrated that this decay is linked to reduction of the capillary network in the brain. In this study, we used an animal model to study the effects of GH after a stroke. Interestingly, we found that if you administer GH for 28 days, we observed significant growth of the fine capillaries in the brain. This, in turn, could provide support for plasticity and recovery processes. Together with other positive effects on synaptic proteins and other relevant growth factors we see this as an interesting translational link where relevant specific mechanisms are further understood.
We believe that these mechanisms are related to the observed improvement of the animals cognitive abilities. This is particularly interesting since cognitive dysfunction after stroke constitutes a huge problem that we try to find different ways to treat.
How far away are we from trialling this in humans?
We are using a drug that is already established in the clinic. Growth hormone has been used for other purposes in humans for decades so the substance has all the necessary approvals already.We aim to start feasibility studies using GH within a year roughly.
What would it mean if the GH is a safe and effective treatment for stroke recovery?
The whole plethora of cognitive problems after stroke constitute a major headache for us and we currently don’t have any treatment that can facilitate cognitive recovery. If we had a drug that could help improving cognitive problems after stroke, it would no doubt be very important.
Professor Michael Nilsson MD FAFRM (RACP) PhD is an internationally well-established neuroscientist with over two decades experience within the fields of astrocyte biology, brain plasticity and recovery after stroke, and a consultant neurologist based at John Hunter Hospital in Newcastle.
In 2012, Professor Nilsson was appointed Director of Hunter Medical Research Institute and Burges Professor of Medical Science at the University of Newcastle. Previously Professor Nilsson was Director of Research, Development and Education at Sahlgrenska University Hospital in Gothenburg, Sweden.
While retaining his research network in Sweden, Australia and internationally he is now building a strong research platform within HMRI. In 2016 he was accepted as a Fellow of the Australasian Faculty of Rehabilitation Medicine (RACP), while in 2017 was appointed Chair of the University of Newcastle’s Centre for Innovative Technologies in Rehabilitation Settings (CITRS).