Flinders Targets Medical 'Black Box'
First Published: Flinders University Encounter - Vol 22, 2011-12
A baffling medical condition whereby those affected ignore everything on one side of their world is the focus of a $375,000 study headed by Flinders University researcher Tobias Loetscher.
Dr Loetscher from the School of Psychology is one of two Flinders researchers who in November received the Australian Research Council's inaugural Discovery Early Researcher Career Award to pursue an area of international significance.
His three-year study, starting in 2012, aims to develop effective treatments for spacial neglect - an attentional disorder in which damage to either hemisphere of the brain leaves its sufferers unable to perceive, process or interact with one side of their environment.
These patients behave as if one half of the world has ceased to exist and ignore all objects and people on the side opposite the brain lesion, resulting in bizarre behaviours such as only eating food from one side of a plate or shaving only half the body.
While the exact number of people affected is unknown, Dr Loetscher said spatial neglect occurs in roughly 40 per cent of stroke victims with damage to the right side of the brain.
"Currently there are no proven effective treatments for this condition - some therapies work for some patients but not for all and that's because there are different subtypes of neglect," the Postdoctoral Research Fellow said.
"For instance there's motor neglect which prevents people from using one side of their body, or perceptual neglect in which patients cannot pay attention to anything on their damaged side," he said.
"So you can't look at it as a homogenous condition because the treatments that are available, including non-invasive brain stimulation and cognitive rehabilitation, might only work depending on what subtype your neglect falls into."
Using mainly behavioural-based studies, Dr Loetscher will evaluate a person's ability to perform visual-motor tasks such as bisecting a line, copying simple drawings and identifying letters in a group with the aim of developing tests to "disentangle the different subtypes of neglect."
In order to achieve his long-term goal of finding effective therapies for spatial neglect, Dr Loetscher said the first and most important step is to understand the inner-workings of the brain, namely how the brain selects information, how space is represented and how it processes locations and objects.
This part of the research will involve brain studies of healthy subjects in the Brain and Cognitive Laboratory at Flinders, working with Professor Mike Nicholls.
The results, he said, could also be used to tackle other similar conditions such as attention deficit hyperactivity disorder and Parkinson's disease.
"Before we can even consider treatments we need to understand how the neural mechanisms controlling spatial attention operate in a healthy brain, and how these mechanisms are altered after brain damage," he said.
"Currently this area is a black box, we have treatments but they aren't that effective so that's why it's important to understand how the brain works - and what can go wrong."
New Targets for the Prevention of Stroke Disability
First Published: Enews - August 2010
Flinders neuroscientists are looking for ways to work with the brain's own adaptive responses to prevent the long term damage and permanent disability which often follows a stroke.
Stroke is Australia's second biggest killer after heart disease, and is the leading cause of disability in Australia. It occurs when there is an interruption of the blood supply to vessels in the brain, which can be caused by a lack of blood flow, a blockage or a haemorrhage.
There is a very short window of time where emergency treatments can be effective in halting and reversing the damage to cells caused by the lack of oxygen and other nutrients.
Professor Neil Sims from the Centre for Neuroscience and Discipline of Medical Biochemistry is looking to readdress the medical belief that a patient needs to have presented to hospital within a few hours of the onset of symptoms in order for treatments to be effective.
"Our research is now asking the question whether we can do anything after initial damage has developed," Professor Sims said.
"During the first few months following their stroke, the brains of patients often show what could be described as an 'adaptive response'. During this time these patients can improve and regain some of the movement they had lost."
Research has shown that scarring of the brain tissue can develop in the months following a stroke, which can limit this ability of the brain to make new connections between nerve cells and to restore neurological function.
"We know changes in brain cells known as glial cells lead to this type of scarring," Professor Sims said. "We are now using a rat model of stroke to determine what the critical changes in the glial cells are, and how we can interfere to prevent scarring."
The research team hope to identify new targets and to develop drug treatments which could promote a patient's recovery.
"Because not all patients realise they are having a stroke, or are unable to present to hospital quickly, the advantage of this approach is that the key events we are trying to modify occur 12 hours to one week after the initial stroke," Professor Sims said.
New Era In Sleep Disorder Diagnosis
First Published: Investigator - June 2009
A Southern Adelaide Health Service research team has developed an award-winning diagnostic tool for GPs to quickly and easily diagnose patients with obstructive sleep apnoea.
Obstructive sleep apnoea is estimated to affect up to 10 percent of the Australian adult population, and is associated with a number of health problems including high blood pressure, daytime sleepiness, and increased risk of heart attack and stroke.
Despite this, Dr Chai said the condition is widely undiagnosed. ‘This is because traditional diagnosis and treatment involves patients undergoing a multi-channel sleep study recording and awaiting review by a Sleep Specialist – a process that can take several months,’ she said. However, the research team’s diagnosis tool may be set to change all that.
The test – developed and validated in patients from six GP clinics across South Australia since 2007 - consists of two simple steps: a short four-item verbal questionnaire and the overnight use of a portable single-channel sleep monitor for those patients identified as possible sleep apnoea sufferers from the questionnaire.
‘We have been able to show that the two-step strategy is a very accurate way of diagnosing obstructive sleep apnoea,’ Dr Chai said.
A second stage of the study involves a larger group of GPs across urban, rural and remote South Australia using the diagnosis tool and patients identified with obstructive sleep apnoea being randomly assigned to the care of either their GP or to usual management in a sleep specialist clinic for a total of six months of follow-up. The research team will then compare the outcomes of care between the two groups.
‘We will look at outcomes in terms of sleepiness levels, symptoms of obstructive sleep apnoea, health care costs, patient satisfaction and adherence to treatment.’
‘Hopefully we will be able to demonstrate that GP-based care is comparable to care by a sleep specialist, which will ultimately mean reduced waiting times and better health outcomes for patients.’
Repairing Brain Damage In Stroke
First Published: Investigator - August 2008
Scientists at Flinders Medical Centre are fine-tuning new technology that could target and deliver treatment to specific groups of brain cells that have been damaged by stroke.
There are billions of different types of cells in the brain, each with their own function and response to injury. Targeting treatment to specific groups of these cells has not been possible before now.
Dr Håkan Muyderman from the Department of Medical Biochemistry and his colleagues have developed a technique that utilises a natural function of cells to deliver genetic material directly into specific brain cells to either repair them or alter their function so they are no longer damaging to the brain.
They have been making good progress and will soon see if this approach can be used to treat the brain damage and behavioural changes that develop in stroke.
Stroke has become the second biggest killer after heart disease in the developed world and is the leading cause of disability in Australia.
An attack can be caused either by a sudden disruption of blood flow to the brain or a haemorrhage that leaks blood into the brain, causing devastating damage to brain tissue.
Dr Muyderman’s research will also help shine light on the role of glial cells (also known as astrocytes), as they have not yet been well defined. Glial cells greatly outnumber nerve cells in the brain and are believed to play many essential roles in normal brain function.
Understanding the role of these cells has been limited as there have been few scientific approaches that have allowed the properties of the cells to be selectively targeted in an intact living brain.
“A gene delivery system capable of selectively targeting sub-populations of brain cells will be of significant value in creating a better understanding of the contribution of these cells to normal brain function and disease,” said Dr Muyderman.
This research could also contribute to better treatments for other diseases of the central nervous system such as Alzheimer’s, Parkinson’s and motor neuron disease.
BankSA Golf Day
First Published: Investigator - February 2008
Professor Neil Sims is investigating stroke and the chemically-induced changes that take place in the brain in response to treatments.
This project is focusing on characterising the effects of these changes in brain cell function to understand if they reduce the damage brought on from impaired blood flow caused by a stroke.
Nerve Damage In Diabetes
First Published: Investigator - July 2006
Understanding diabetic associated nerve damage in the anorectal region is a key focus for Dr Penny Lynn, Senior Research Officer within the Department of Human Physiology at Flinders.
Diabetes forms when blood sugar levels are not controlled either through a decreased production of insulin within the body or the body’s inability to respond to the insulin that is produced. Keeping the blood sugar levels within a normal limit is the best way to reduce or prevent the complications associated with diabetes such as cardiovascular diseases, chronic renal failure, retinal and nervous system damage.
For many with diabetes, the nerve damage can lead to embarrassing complications such as faecal incontinence. This is due to the nerves in the anorectal area being no longer able to properly control the defecation process.
Up to 20% of diabetics experience some sort of defecation related complication such as faecal incontinence over the course of their disease. Understanding which nerves are damaged and in what order they are damaged will lead to a better awareness of the mechanisms causing this symptom and could lead to a better way of controlling or preventing this distressing problem.
“This symptom, while not the most serious, is indicative of an awful lot of nerve damage,” says Dr Lynn. “Many people don’t report this problem as they are too embarrassed, however it is quite common and with more awareness in the processes that lead to this issue we may be able to create a solution.”
Currently little is known about the groups of nerves within this area. A large portion of Dr Lynn’s project will be to identify which types of nerves sense activity in the anorectal area. Once these have been identified it will be easier to trace how diabetes causes this damage.
If the groups of nerves which are predisposed to this type of damage are successfully identified the Flinders team will be one step closer to creating a drug which can protect them.