Mechanisms Of Cortical Plasticity And Facilitation Of Functional Recovery Following Stroke
Funder
National Health and Medical Research Council
Funding Amount
$427,500.00
Summary
Specific regions of the human brain have been shown to reorganise following damage to the brain or peripheral nerves. This reorganisation is seen in both young and older subjects and is thought to be useful in helping to restore function. For example, following a stroke a patient may, initially, be unable to move one arm. However, in the following weeks and months some function may return. A number of mechanisms may be responsible for this improvement. However, it is likely that at least some of ....Specific regions of the human brain have been shown to reorganise following damage to the brain or peripheral nerves. This reorganisation is seen in both young and older subjects and is thought to be useful in helping to restore function. For example, following a stroke a patient may, initially, be unable to move one arm. However, in the following weeks and months some function may return. A number of mechanisms may be responsible for this improvement. However, it is likely that at least some of the improvement is due to reorganisation within the sensorimotor cortex. Following the stroke the control of the arm may be taken over by adjacent undamaged regions of the brain. This reorganisation allows impressive functional recoveries to occur. We have preliminary evidence to support the idea that patterns of activity generated in peripheral nerves (afferent input) following stroke may be crucial for the development of the organisational changes seen within the brain. We have shown that by applying specific patterns of sensory input we are able to produce organisational changes within the motor cortex of control subjects. Also, we have been able to induce similar changes in stroke patients. These changes have been accompanied by improvements in motor control. These novel and exciting findings support our hypothesis that by applying certain patterns of afferent input to patients following stroke we will be able to facilitate functional recovery by maximising reoganisation within the cortex. In the present project we will establish the organisation patterns in the brain of stroke patients and contrast the findings with control subjects. Secondly we will investigate the potential for facilitating recovery of stroke patients by the application of specific patterns of afferent input. These novel experiments may lead to important therapeutic developments that will benefit the large population of patients suffering strokes.Read moreRead less
Understanding The Human Hand In Grasping And How This Changes After Stroke
Funder
National Health and Medical Research Council
Funding Amount
$227,855.00
Summary
The hand allows remarkable feats of dexterity. But, paralysis of the hand severely limits daily activities and is common after stroke. We will determine key mechanisms that control the hand at the level of the brain and spinal cord. We will assess some limits that develop in the muscle itself. Stroke patients will be tested so that we can better understand the brain�s control of the hand and use this to enhance recovery of hand performance in those with impaired function.
Pain changes movement. Although undisputed, there is a surprising lack of agreement regarding the underlying mechanisms. This project involves an innovative mix of neurophysiological methods to investigate the drive to muscle cells from the nervous system and changes in the mechanics of contraction. These studies will resolve the perplexing problem of how pain changes our ability to activate muscle. Clear understanding of the underlying mechanisms can guide rehabilitation.
The Efficacy Of Novel, Non-robotic Devices To Train Reaching Post Stroke
Funder
National Health and Medical Research Council
Funding Amount
$491,605.00
Summary
Up to 50% of stroke survivors are left with upper limb disability that limits their daily activities and their paralysis is so severe that it excludes them from training with the most effective methods. This study is a clinical trial of innovative new techniques to assist people with severe upper limb paralysis to reach following stroke. Positive results are likely to reduce disability in a large number of stroke survivors and has the potential to be used by other patients with paralysis.
Experience drives changes in the connections between neurons in the brain. This neuroplasticity is a fundamental property of the nervous system, critical for learning and memory, but also important for recovery from injury and development of some nervous system disorders. This study will improve understanding of how, with practice, the human brain adapts to functional demands in the development of motor skill. Musicians are used as exemplars of fine motor skill who show long-term experience-driv ....Experience drives changes in the connections between neurons in the brain. This neuroplasticity is a fundamental property of the nervous system, critical for learning and memory, but also important for recovery from injury and development of some nervous system disorders. This study will improve understanding of how, with practice, the human brain adapts to functional demands in the development of motor skill. Musicians are used as exemplars of fine motor skill who show long-term experience-driven plasticity in the brain. This study will provide specific and detailed quantitative information about how motor cortex circuits important for control of the hand are altered in musicians. The study will also improve understanding of basic mechanisms involved in short-term neuroplasticity associated with motor learning in musicians and non-musicians, and hemispheric or training-related differences in these properties which may contribute to different abilities to use the hand for fine motor tasks.Read moreRead less
The Role Of Afferent Input In The Development Of Focal Task Specific Dystonia
Funder
National Health and Medical Research Council
Funding Amount
$213,000.00
Summary
The term dystonia is used to describe a condition that is characterised by abnormal muscle activation patterns. This leads to impaired control of voluntary movements. Depending upon which part of the body is affected, dystonia may be classified as generalised (affecting two or more body segments), hemi (involving one side), segmental (involving adjacent body parts or a segment), or focal (affecting one part of the body). Many of the focal dystonias are also task specific and the aim of this prop ....The term dystonia is used to describe a condition that is characterised by abnormal muscle activation patterns. This leads to impaired control of voluntary movements. Depending upon which part of the body is affected, dystonia may be classified as generalised (affecting two or more body segments), hemi (involving one side), segmental (involving adjacent body parts or a segment), or focal (affecting one part of the body). Many of the focal dystonias are also task specific and the aim of this proposal is to investigate these task-specific focal dystonias. Task-specific focal dystonia is common in the community and causes considerable suffering and loss of productivity. For example, writer's cramp (a common form of task specific focal dystonia) is probably the commonest cause of writing difficulty in patients in whom this is the sole complaint. No treatment regimen has been shown to be effective in alleviating it's often debilitating symptoms. The aim of these studies is to further define the pathophysiological changes seen in task-specific dystonia and investigate the mechanisms responsible for their generation. Using the techniques of transcranial magnetic stimulation and peripheral nerve stimulation we will investigate the organisation of the motor cortex in this condition and examine the influence of afferent input on intrinsic cortical circuitry. We hypothesise that the motor regions of the brain are more sensitive to the particular repeated patterns of sensory information reaching the brain during repetitive movement and this results in abnormal alterations in organisation that may be responsible for the symptoms of dystonia. Additionally, we predict that it may be possible to reverse these organisational changes by applying novel patterns of nerve stimulationRead moreRead less
Changes In Motor Control And Kinaesthetic Sensations After Eccentric Exercise.
Funder
National Health and Medical Research Council
Funding Amount
$287,250.00
Summary
It is a well-known observation that after a period of intense exercise we are unsteady on our feet and are clumsy when attempting to make precision movements. Such impressions are particularly marked after eccentric exercise, during which the contracting muscles are forcibly lengthened. Activities such as walking downhill, skiing and horse riding involve eccentric exercise. The debilitating consequences of this kind of exercise are attributed, not just to the post-exercise effects of fatigue, bu ....It is a well-known observation that after a period of intense exercise we are unsteady on our feet and are clumsy when attempting to make precision movements. Such impressions are particularly marked after eccentric exercise, during which the contracting muscles are forcibly lengthened. Activities such as walking downhill, skiing and horse riding involve eccentric exercise. The debilitating consequences of this kind of exercise are attributed, not just to the post-exercise effects of fatigue, but to loss of muscle force from damage to fibres. Eccentric exercise also leads to longer term effects. The breakdown of the damaged tissue leads to sensations of stiffness and soreness the next day. This application proposes experiments aimed at studying a number of effects of eccentric exercise on motor control, and establishing the muscle, spinal and brain levels at which they occur. Three studies are planned. In the first, the question will be explored whether we are less able to use the motor areas of our brains to execute voluntary contractions after exercise. So fatigue is not just a matter of exhausted muscles but perhaps also exhausted brains. We will use brain and spinal cord stimulation to explore this point. Then we plan to listen to single motor units, the basic elements of muscle control, to try to understand the mechanism by which the brain minimises the debilitating effects of fatigue. Finally we want to examine subjects' ability to locate their limbs in space as a means of providing a basis for the clumsiness we experience after intense exercise. These are all important issues relevant to clinical medicine and rehabilitation as well as sports science and exercise.Read moreRead less
One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. We will address one particular aspect of this problem, namely the organisation of the cortical areas that provide visual control for skilled movement ....One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. We will address one particular aspect of this problem, namely the organisation of the cortical areas that provide visual control for skilled movements. It is proposed that there are two parallel brain circuits involved in the analysis of motion, one tracking the movement of objects, and the other analysing a person s self-motion. Consider, for example, the task of a tennis player who has to return a serve. In order to achieve this, the brain must precisely integrate information about the ball s motion, as well as information about the player s speed and direction. This requires precise control of eye movements (to keep the eyes on the ball), as well as the ability to control the limb and trunk muscles. The aim of this study will be to map the anatomical framework underlying our ability to process all the relevant visual motion information, and to coordinate the appropriate motor responses. Such work is fundamental for understanding the functional organisation of the brain. It also has the potential to lay the groundwork for developments in areas of applied research, including medicine (e.g. the design of better rehabilitation strategies for people with brain damage), robotics- artificial intelligence (e.g. the improvement of artificial systems capable of vision), and the cognitive sciences (e.g. a better understanding of factors that limit human responses to visual stimuli).Read moreRead less
Bilateral Movement Therapy In Post-stroke Hemiparesis
Funder
National Health and Medical Research Council
Funding Amount
$265,993.00
Summary
Stroke is the leading cause of long-term disability in adults in Australia, accounting for approximately 25% of all disability. A common motor disability resulting from stroke is hemiparesis, weakness or paralysis on one side of the body. This disability severely impairs an individual's capacity to perform activities of daily living, making them dependent on relatives and health professionals for daily care. By developing effective interventions to treat stroke-induced hemiparesis both the disab ....Stroke is the leading cause of long-term disability in adults in Australia, accounting for approximately 25% of all disability. A common motor disability resulting from stroke is hemiparesis, weakness or paralysis on one side of the body. This disability severely impairs an individual's capacity to perform activities of daily living, making them dependent on relatives and health professionals for daily care. By developing effective interventions to treat stroke-induced hemiparesis both the disability caused by stroke and the associated personal and financial costs will be lessened. A number of interventions focusing on the affected side (unilateral), including active movements and muscle stimulation are being investigated as possible treatments for stroke-induced hemiparesis. Recent evidence suggests that involving the unaffected side simultaneously (bilateral therapies) could be effective, and may provide addtional benefits over unilateral therapies. The aim of this research is to thoroughly examine the effectiveness of bilateral therapies by incorporating them into established interventions. The findings from these studies will aid in the development and refinement of movement therapies aimed at promoting recovery from stroke-induced hemiparesis.Read moreRead less