An Extended Follow-up Of Stroke Patients For Cognitive Impairment And Neuropsychiatric Disorders: Sydney Stroke Study
Funder
National Health and Medical Research Council
Funding Amount
$321,800.00
Summary
Vascular Dementia (VaD) is the second most common cause of dementia after Alzheimer's disease. In fact, it may be a preventable cause of dementia. Yet it has been relatively neglected by researchers until the last decade, which has seen an upsurge of interest in this disorder. There is no consensus on the criteria for dementia. The profile of early cognitive impairment due to vascular factors is still poorly understood, and the longitudinal course of VaD as defined by modern criteria has not bee ....Vascular Dementia (VaD) is the second most common cause of dementia after Alzheimer's disease. In fact, it may be a preventable cause of dementia. Yet it has been relatively neglected by researchers until the last decade, which has seen an upsurge of interest in this disorder. There is no consensus on the criteria for dementia. The profile of early cognitive impairment due to vascular factors is still poorly understood, and the longitudinal course of VaD as defined by modern criteria has not been studied. There have been few studies of the progressive changes in MRI in patients with cerebrovascular disease. The overlap of VaD and Alzheimer's disease (AD) remains a problem for taxonomists and clinicians. One approach to the study of VaD is to examine a high risk group of subjects longitudinally to determine the early features, the risk factors and progressive changes. With this in mind, we began studying a cohort of stroke patients who are at high risk of VaD, in 1997-1999, and are following them longitudinally. The follow-up is now in its third year, and three neuropsychological assessments and two MRI-MRS scans have been performed. We propose to extend the follow-up to 5 years, with repeat neuropsychiatric, neuropsychological and MRI-MRS investigations, and wherever possible to necropsy, to determine the nature of vascular pathology that underlies cognitive impairment. Our cohort of stroke patients is arguably the most comprehensively assessed such cohorts internationally, and presents an excellent opportunity for a long-term follow-up study.Read moreRead less
THE NATURAL HISTORY OF COGNITIVE IMPAIRMENT AND DEMENTIA IN A STROKE COHORT
Funder
National Health and Medical Research Council
Funding Amount
$290,747.00
Summary
In a current NHMRC-funded study, we have examined 200 stroke patients (and 100 control subjects) at 3 months after a stroke and one year later, and identified those who have impairment in memory and other cognitive functions. We have also studied these subjects in detail from a psychiatric perspective and performed brain scans on them using magentic resonance imaging. We find that many stroke patients have problems with their cognitive functioning which has a major impact on their lives. A large ....In a current NHMRC-funded study, we have examined 200 stroke patients (and 100 control subjects) at 3 months after a stroke and one year later, and identified those who have impairment in memory and other cognitive functions. We have also studied these subjects in detail from a psychiatric perspective and performed brain scans on them using magentic resonance imaging. We find that many stroke patients have problems with their cognitive functioning which has a major impact on their lives. A large number also become depressed. These consequences of stroke are not given sufficient importance by clinicians. The fact that stroke is a common problem in the elderly, and our society is aging, makes this a problem of major public health significance. In the new proposal, we plan to study these subjects up to 3 years with repeat neuropsychiatric assessments and brain scans to investigate the natural history of stroke-related cognitive impairment. We will determine whether further new cases of dementia develop in the period 1-3 years, what happens to the brain lesions picked up on brain scans, and how these deficiencies affect the patients' living status and their longevity. We will be able to determine the factors that lead to a good outcome, and suggest strategies that may be applicable to improve the functioning of these individuals.Read moreRead less
Identification Of Heterogeneity In Vasodilator Function In Human And Rat Resistance Vessels: Potential Drug Targets?
Funder
National Health and Medical Research Council
Funding Amount
$595,330.00
Summary
The balance between the ways that blood vessels decrease in size (constrict) and increase in size (dilate) determine how blood vessels normally function. There are many differences in the ways that blood vessels control this balance in different parts of the body. Such differences are altered in vascular diseases, such as hypertension and diabetes, which are prevalent in obesity, such that constriction generally outweighs dilation. However, what these differences are and how they occur are not w ....The balance between the ways that blood vessels decrease in size (constrict) and increase in size (dilate) determine how blood vessels normally function. There are many differences in the ways that blood vessels control this balance in different parts of the body. Such differences are altered in vascular diseases, such as hypertension and diabetes, which are prevalent in obesity, such that constriction generally outweighs dilation. However, what these differences are and how they occur are not well understood. While current drugs for treating vascular disease either reduce vessel constriction or increase dilation, they are not specific for individual arteries; a situation that would allow us to control vascular diseases in a very specific manner. Recently, we have described differences between the ways that individual vessels are controlled. These changes relate to differences in the way that different vessels dilate. AIMS - To further understand normal blood vessel function and the changes that occur in blood vessels in cardiovascular disease, with a focus on the ways that blood vessels dilate in normal states and in obesity-related diseases, such as in hypertension and diabetes. - The eventual aim is to identify the specific ways that arteries function, so that artery-specific drug targets can be identified to treat disease-related changes in cardiovascular disease in a very specific manner. EXPECTED OUTCOMES This project will contribute to understanding blood vessel function in health and disease. The expected eventual outcome is the identification of the mechanisms that underlie the function of different arteries in different parts of the body, so that specific individual vessel function can be targeted to treat vascular disease. Additionally, this work will also verify the relevance of the diet-induced obesity animal model, in terms of the characteristics and causes of human obesity and related cardiovascular disease.Read moreRead less
The Role Of Snoring Vibrations In The Pathogenesis Of Early Carotid Artery Atherosclerosis
Funder
National Health and Medical Research Council
Funding Amount
$593,833.00
Summary
Habitual snoring is a very common problem in the adult population, with a prevalence of between 20-40%. Increasingly it is now recognised that snoring may be an independent risk factor for the development of stroke. In this proposal, we will explore the hypothesis that chronic snoring transmits a pressure wave through the tissues of the neck to the carotid artery which may damage the artery wall and subsequently lead to stroke. This may lead to new strategies to treat habitual snoring.
Sympathetic Control Of Cutaneous Blood Flow And Blood Pressure In Human Spinal Cord Injury
Funder
National Health and Medical Research Council
Funding Amount
$242,002.00
Summary
While spinal cord injury can cause devastating changes in the nervous system paralysis and loss of sensation relatively little is known about changes to the sympathetic nervous system. The sympathetic nervous system is intimately involved in the ongoing control of blood pressure, blood flow and temperature control. Loss of sympathetic control can occur following spinal cord injury. Interruption of descending pathways can result in partial or complete loss of sympathetic outflow from the thoracol ....While spinal cord injury can cause devastating changes in the nervous system paralysis and loss of sensation relatively little is known about changes to the sympathetic nervous system. The sympathetic nervous system is intimately involved in the ongoing control of blood pressure, blood flow and temperature control. Loss of sympathetic control can occur following spinal cord injury. Interruption of descending pathways can result in partial or complete loss of sympathetic outflow from the thoracolumbar segments. Complete decentralization can result in autonomic dysreflexia (autonomic hyperreflexia), in which sensory stimuli originating below the lesion evoke a reflex increase in sympathetic drive to the blood vessels, causing them to constrict. Because of this, blood pressure may rise suddenly and remain at such high levels that stroke and (occassionally) cardiac arrest may occur. This phenomenon, autonomic dysreflexia, is considered a medical emergency. The typical subjective signs of autonomic dysreflexia include a throbbing headache, tingling in the head or nasal congestion; sweating and flushing above the lesion are clinical signs that prompt medical staff to measure blood pressure and to locate the source of sensory irritation (usually a distended bladder or impacted colon, sometimes a pressure sore or ingrown toenail). Commonly, however, subclinical episodes go undetected, and this phenomenon of silent dysreflexia is of increasing concern. This project will develop means of assessing the integrity and state of the sympathetic nervous system below a lesion in patients with spinal cord injury and characterize the firing properties of reflexly activated sympathetic neurones.Read moreRead less
THE VASCULAR CONSEQUENCES OF SNORING AND OBSTRUCTIVE SLEEP APNOEA
Funder
National Health and Medical Research Council
Funding Amount
$476,052.00
Summary
Snoring refers to a condition where the throat narrows significantly during sleep, and allows the soft tissues which surround this part of the airway to vibrate and create the typical snoring noise. Habitual snoring is a very common problem in the adult population, with a prevalence of between 20-40%. More severe forms of snoring are associated with the obstructive sleep apnoea syndrome, which is a condition in which the throat completely blocks behind the tongue and palate during sleep leading ....Snoring refers to a condition where the throat narrows significantly during sleep, and allows the soft tissues which surround this part of the airway to vibrate and create the typical snoring noise. Habitual snoring is a very common problem in the adult population, with a prevalence of between 20-40%. More severe forms of snoring are associated with the obstructive sleep apnoea syndrome, which is a condition in which the throat completely blocks behind the tongue and palate during sleep leading to cessation of breathing for short periods of time. Sleep apnoea is among the commonest chronic disorders of adult males occurring in 5% of men over the age of 45 years. Increasingly, it is now recognised that snoring, without sleep apnoea, may be an independent risk factor for the development of both of these very common and significant medical disorders. However, there have been no studies exploring the mechanisms by which snoring might contribute to the development of stroke and hypertension. In this proposal, we will explore the hypothesis that chronic snoring transmits a pressure wave through the tissues of the neck to the carotid artery which is the main blood supply to the brain. We propose that the chronic vibration of this artery leads to disease such as atherosclerosis and hypertension. Our studies will help to prove that this is a common mechanism whereby both snoring and sleep apnoea may contribute to the development of important vascular diseases. Studies will also establish the prevalence of carotid atherosclerosis in snorers (with and without OSA), and the prevalence of habitual snoring and OSA in patients at risk of developoing completed stroke. The recognition of snoring as an independent risk factor for vascular disease will clearly have important and wide ranging implications for the future management of snoring in the prevention of stroke and hypertension.Read moreRead less
The Australian Parkinson's Project - Uncovering Genetic Risk Factors For Sporadic PD
Funder
National Health and Medical Research Council
Funding Amount
$768,546.00
Summary
Parkinson s disease (PD) is a progressively disabling movement disorder afflicting many elderly Australians. It is caused by the degeneration of specific nerve cells in the brain that produce certain chemicals and patients suffer from an inability to move fluently (or ultimately at all). At present we do not know what triggers this neurodegeneration, but it is believed that complex interactions between inherited (genetic) and environmental factors contribute significantly to the phenomenon. This ....Parkinson s disease (PD) is a progressively disabling movement disorder afflicting many elderly Australians. It is caused by the degeneration of specific nerve cells in the brain that produce certain chemicals and patients suffer from an inability to move fluently (or ultimately at all). At present we do not know what triggers this neurodegeneration, but it is believed that complex interactions between inherited (genetic) and environmental factors contribute significantly to the phenomenon. This project aims to learn more about these complex interactions and their association with PD. People with PD and unaffected individuals will be recruited from throughout Australia and we will look for specific combinations of genetic, environmental and lifestyle factors that either increase or decrease an individual's risk for PD. This research will identify the most common dominant genetic and environmental influences for PD in Australia, enabling scientists to focus on the most relevant biological pathways to target therapeutically.Read moreRead less