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.
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
Novel Assessments Of The Central And Peripheral Control Of The Human Hand
Funder
National Health and Medical Research Council
Funding Amount
$365,105.00
Summary
This is a study of how the human hand works. The hand is supremely adapted for manual skills ranging from writing and playing a musical instrument to non-verbal communications via gesture and pointing. How is the range of hand skills achieved? We are motivated to study this because the ability of the hand to recovery from some neurological disorders, particularly stroke, is very poor. One important element in virtually all activities of the hand is precise movement of the thumb. The tip of the t ....This is a study of how the human hand works. The hand is supremely adapted for manual skills ranging from writing and playing a musical instrument to non-verbal communications via gesture and pointing. How is the range of hand skills achieved? We are motivated to study this because the ability of the hand to recovery from some neurological disorders, particularly stroke, is very poor. One important element in virtually all activities of the hand is precise movement of the thumb. The tip of the thumb is flexed by a single muscle, a muscle only present in humans. We want to determine how this muscle works, and how the force it produces affects the whole hand. We will use specialised neurophysiological techniques to do this in human volunteers. There is no comparable animal model for this type of work due to significant differences at both the level of the brain and the level of the muscle. Second, we want to understand better how the cells in the spinal cord which control the hand (and other) muscles work. We have two new ways to do this, including a novel technique which can activate these cells with a form of stimulation that may help us improve functional electrical stimulation. Finally, with 27 bones and more than 25 muscles which operate it, the hand is not simple to control. We will use a new apparatus to measure how well it is controlled, and we will directly stimulate the motor areas of the brain to evaluate the control. From this, we will come up with new understanding, as well as new stimulus and measurement techniques that can be applied to patients with impaired hand function, as occurs all too often after stroke.Read moreRead less
Neural Mechanisms Underlying Human Grasp And Manipulation
Funder
National Health and Medical Research Council
Funding Amount
$396,100.00
Summary
We rely on hand function in a multitude of simple tasks that we tend to take for granted but that are essential in our everyday lives; some examples are turning on a tap, doing up shoelaces, or holding a cup. Many people in the community are disabled by impaired hand function resulting from lesions of the central nervous system or peripheral nerve lesions. The size of the problem is enormous; manual dexterity is affected in approximately 20,000 new stroke patients each year in Australia as well ....We rely on hand function in a multitude of simple tasks that we tend to take for granted but that are essential in our everyday lives; some examples are turning on a tap, doing up shoelaces, or holding a cup. Many people in the community are disabled by impaired hand function resulting from lesions of the central nervous system or peripheral nerve lesions. The size of the problem is enormous; manual dexterity is affected in approximately 20,000 new stroke patients each year in Australia as well as in other neurological diseases such as neuropathies, nerve injuries, cerebral palsy and many others. The broad aim of this study is to investigate the poorly understood neural mechanisms that underlie sensorimotor control of hand function. We will target a specific aspect of manual dexterity that is crucial for the execution of common everyday tasks, like pouring liquid from a bottle, in which the digits are subjected to torsional loads. In order to maintain stable grasps, the motor control system must rapidly and automatically adjust the grip forces employed to meet the demands imposed by the changing torsion. This is only possible because of sensory feedback from the hand, a large component of which arises from the cutaneous mechanoreceptive afferent fibres. In the first two years we will use a combined approach of neural recording from peripheral nerves in anaesthetised monkeys and psychophysics experiments in normal humans to answer the general question: how does the population of cutaneous afferents provide precise feedback about torsion on the digits? In the third year we will perform key experiments in humans, using microneurography to record from their peripheral nerves. This will establish any differences between human and monkey mechanoreceptors.Read moreRead less
Clinical Efficacy And Physiological Mechanisms Of Nerve And Tendon Gliding Exercises For Carpal Tunnel Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$370,068.00
Summary
Compression of one of the major nerves at the wrist (carpal tunnel syndrome) is a very common condition that significantly impacts on the well-being of the patient. To date, there is no good evidence that traditionally advocated interventions are effective in the long term. This project will evaluate the effects of a novel, active treatment strategy and will investigate the underlying mechanisms that may be associated with exercises that aim to mobilise the nerve and tendons at the wrist.
I will use non-invasive brain stimulation to study the operation of the corticospinal pathway in humans while they perform tasks requiring precise control of fingers and thumb. This pathway from brain to spinal cord is important for independent finger movements, and these experiments will provide insight into the cortical mechanisms by which independent finger movements are produced. I will also investigate relationships between patterns of corticospinal activation (which I have shown differ bet ....I will use non-invasive brain stimulation to study the operation of the corticospinal pathway in humans while they perform tasks requiring precise control of fingers and thumb. This pathway from brain to spinal cord is important for independent finger movements, and these experiments will provide insight into the cortical mechanisms by which independent finger movements are produced. I will also investigate relationships between patterns of corticospinal activation (which I have shown differ between subjects and hands) and digital dexterity. While it seems reasonable to assume that digital dexterity is dependent on the operation of the corticospinal system, the relationship is obscure, even at a gross level. Digital dexterity can vary considerably between subjects, and even between hands in the same subject. Are people more skilled with their hands because they are better able to engage the corticospinal system in control of the digits? The present study will address this fundamental question. The brain stimulation techniques that I will use are the only techniques presently available which can answer these questions in humans. This information will assist us to understand how normal subjects perform skilled tasks with their hands, as well as helping us to understand how damage to the nervous system (e.g., stroke, multiple sclerosis, Parkinson's disease) produces deficits in movement control. The information gained may suggest training regimes for skill acquisition in normal subjects, and to promote recovery of function in patients with neurological damage or disease.Read moreRead less