Associate Professor Gustin is the Rebecca L. Cooper Fellow, senior neuroscientist and psychologist at NeuRA & UNSW and Head of the Pain Imaging Laboratory at NeuRA and UNSW. She also leads the Pain Research, Education and Management (PREM) program at NeuRA and UNSW. Associate Professor Gustin completed her PhD in Psychology at the University of Tuebingen, Germany in 2006 and immigrated to Australia in 2007 to take up a postdoc position at the University of Sydney. In 2009 Associate Professor Gustin was awarded a Career Development Fellowship by the NSW Office for Science and Medical Research. In 2015 Associate Professor Gustin moved her laboratory to NeuRA and UNSW. Her research is funded by the Australian National Health and Medical Research Council (NHMRC), the Rebecca L. Cooper Medical Research Foundation, the International Association for the Study of Pain (IASP), the US Department of Defence, the NSW Defence Innovation Network and the NSW Office for Science and Medical Research (OSMR).
For the past 20 years (13 years postdoc, self-funded) Associate Professor Gustin has been using brain imaging techniques and psychological assessment to investigate the central and psychological circuits underlying chronic pain in humans. She has experience in the use of many brain imaging techniques such as magnetoencephalography and functional, structural and biochemical magnetic resonance imaging. In addition, Associate Professor Gustin has practised as a psychologist focusing on the management of chronic pain. Her aim is to increase our understanding of the development and maintenance of chronic pain, in particular psychological and central components and their association with each other. And most importantly to develop and evaluate novel interventions that can provide pain relief via the primary source of pain: the brain.
A person with spinal cord injury cannot feel touch. When touch information is forwarded from the periphery, e.g. the big toe, the brain represents a new category – discomplete spinal cord injury – which requires a new approach to rehabilitation. A new phase of this research program will study how to enhance these surviving sensory spinal nerve pathways with an intensive stimulation of the areas which represent touch in the brain to ultimately restore a perception of touch.
Together with Corey Shum and Associate Professor Zina Trost (University of Alabama, USA), Dr Gustin is developing a novel approach of Virtual Reality Walking Intervention (VRWalk) to enhance both the surviving sensory spinal nerve pathways and the touch signal in the brain in people with a discomplete spinal cord injury to finally restore the perception of touch.
The VRWalk intervention is facilitated by a commercially- available head-mounted display and wearable wrist sensors equipped with lightweight accelerometers. These detect participant arm movement during gait motion, translating arm swings into synchronised leg movement in the virtual world.
Participants’ arms and legs are represented from a first-person perspective in a fully immersive 360-degree virtual scene. System mechanisms function to optimally map participants’ actions to those of the virtual avatar, ensuring that virtual motion is directly related to participant intent (and moderating vestibular discomfort). The system dynamically adjusts sound and haptic feedback from virtual “footfalls”, accounting for scene characteristics.
Gaming elements are central to the VRWalk design both to facilitate goal-directed activity through interaction with VR
world objectives and to engage active interest. Optimal kinematic configuration in the virtual environment and relationship between physical and virtual body were addressed as part of initial testing by spinal cord injury stakeholders.
“Our primary aim is to examine whether a 20-day course of 30-minute VRWalk intervention offers clinically meaningful restoration of touch perception in people with discomplete spinal cord injury,” says Dr Gustin.
The research team will also use neuroimaging data, focusing specifically on changes in brain areas which represent touch and movement.
As a result of these developments, the research will provide the evidence base to develop new policies for diagnostic classification of spinal cord injuries, e.g. including discomplete injuries, not only in Australia but globally. This would be a game changer and provide a new future for close to 50 per cent of all people currently living with a complete spinal cord injury.
Researchers from NeuRA, the University of New South Wales the University of Sydney, and HammondCare have found surviving sensory spinal nerve connections in 50 per cent of people living with complete thoracic spinal cord injuries.
The study, which is part of a decade-long collaboration between the researchers, used cutting-edge functional MRI (fMRI) technology to record neural response to touch. It was Dr Sylvia Gustin who analysed the fMRI images to identify the moment the patient’s brain registered the touch.
“Seeing the brain light up to touch shows that despite the complete injury to the thoracic spine, somatosensory pathways have been preserved,” explains Dr Gustin.
“It’s fascinating that although the patients did not ‘feel’ the big toe stimulation in the experiment, we were able to detect a significant signal in response to the touch in the brain’s primary and secondary somatosensory cortices, the thalamus, and the cerebellum.”
For those living with a complete spinal cord injury this means, despite previously believing the communication to the brain had been severed in the injury, messages are still being received. Dr Gustin describes this new category of spinal cord injury as ‘discomplete’
“The current classification system is flawed. It only contains two types of spinal cord injury – complete and incomplete,” says Dr Gustin.
“It is important we acknowledge there is a third category – the ‘discomplete’ injury, only then we can provide better treatment regimens for the many sufferers of a complete spinal cord injury.”
For those newly classified as ‘discomplete’, this discovery opens up new opportunities to identify those people living with a spinal cord injury that are more likely to benefit from treatments aimed at improving sensation and movement. Because of this study, research participant, James Stanley, now knows he belongs to a new category.
“It is exciting to know that there is a connection there, that my toe is trying to say hello to my brain,” says James.
“If medical professionals can work to identify people like me with a ‘discomplete’ injury earlier, perhaps they can find new treatments and rehabilitation techniques.
“The thought that one day I might be able to feel the sand between my toes again, or the waves wash over my feet gives me hope. It’s something Dr Gustin’s discovery has made possible.”
Alterations in the grey matter volume of several brain regions have been reported in people with chronic pain. The most consistent observation is a decrease in grey matter volume in the medial prefrontal cortex. These findings are important as the medial prefrontal cortex plays a critical role in emotional and cognitive processing in chronic pain. Although a logical cause of grey matter volume decrease may be neurodegeneration, this is not supported by the current evidence. Therefore, the purpose of this review was to evaluate the existing literature to unravel what the decrease in medial prefrontal cortex grey matter volume in people with chronic pain may represent on a biochemical and cellular level. Our model proposes new mechanisms in chronic pain pathophysiology responsible for mPFC grey matter loss as alternatives to neurodegeneration.