The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

Hilmi Uysal - One of the best experts on this subject based on the ideXlab platform.

  • Modified Motor unit number index (MUNIX) algorithm for assessing excitability of Alpha Motor Neuron in spasticity
    Clinical neurophysiology practice, 2018
    Co-Authors: Serkan Uslu, Tunca Nüzket, Hilmi Uysal
    Abstract:

    Abstract Objective The understanding of the spasticity mechanism is still a problem in the literature, as its definition can be made on the basis of more than one parameter. Therefore, we studied Alpha Motor Neuron excitability, dynamic changes based on force production, and patellar tendon (T) reflex in spasticity and healthy control groups. Methods Alpha Motor Neuron excitability, force production, and patellar T reflex were evaluated through three different test protocols. Motor Unit Number Index (MUNIX) measurement was applied for understanding Motor Neuron pool properties in the first protocol. Voluntary force production and patellar T reflex parameters were evaluated by voluntary force production and triggering patellar T reflex. Twenty spasticity and 20 healthy volunteers participated in the study. Results In the spasticity group, both MUNIX numbers and Motor Unit Size Index (MUSIX) numbers were lower than those in the control group. The results for the Ideal Case Motor Unit Count (ICMUC) parameter show that there is no significant difference between spasticity and healthy individuals for low-level contractions, whereas there is a significant difference for high-level contractions (p  Conclusion Spasticity and healthy subjects can be distinguished easily and clearly by evaluating the changes in both kinesiological and electrophysiological findings and the decreasing threshold in the Alpha Motor Neuron pool. Significance This study shows that such combined methods, which allow the evaluation of the Alpha Motor Neuron pool, as well as kinesiological and electrophysiological parameters, are tools that cannot be overlooked in understanding spasticity.

  • O121 Alpha Motor Neuron excitability and force generation in spasticity
    Clinical Neurophysiology, 2017
    Co-Authors: Serkan Uslu, Tunca Nüzket, Can Ozcan, Suha Yagcioglu, Hilmi Uysal
    Abstract:

    Objective The aim of this study was to evaluate the Motor unit number, voluntary and reflex force produced by Alpha Motor Neuron excitability in spasticity. For this purpose, electrophysiological and dynamic measurements were taken from spasticity cases and healthy participants. Method Patient group consisted of 20 spasticity and healthy group consisted of 20 healthy individuals. The force values produced by triggering the Patella T reflex were calculated via the acceleration sensor. For calculation of the force at the Patellar Tendon during Patellar Reflex triggered force production, we used fundamental principle of leverage with acceleration sensor data. The force obtained by this measurement is defined as reflexive force. Motor unit numbers of participants were evaluated according to MUNIX algorithm. Results There were statistically significant differences between the spasticity cases and healthy control group both for Motor unit number and the high level voluntary force production and the force generated by reflex triggering ( p Discussion This study shows that such combined methods, which allows the evaluation of the Alpha Motor Neuron pool, as well as the kinesiological and electrophysiological parameters, are tools that cannot be overlooked in understanding spasticity. Conclusion Motor unit number and force generation were evaluated in spasticity and healthy individuals and statistically significance differences in these features were obtained between two groups. Significance Motor unit number of rectus femoris muscle in spasticity is measured by MUNIX algorithm. Evaluating of voluntary and reflex-generated force with Motor unit number have a potential tool for investigating spasticity.

Thomas H Gillingwater - One of the best experts on this subject based on the ideXlab platform.

  • selective loss of Alpha Motor Neurons with sparing of gamma Motor Neurons and spinal cord cholinergic Neurons in a mouse model of spinal muscular atrophy
    Journal of Anatomy, 2016
    Co-Authors: Rachael A Powis, Thomas H Gillingwater
    Abstract:

    Spinal muscular atrophy (SMA) is a neuromuscular disease characterised primarily by loss of lower Motor Neurons from the ventral grey horn of the spinal cord and proximal muscle atrophy. Recent experiments utilising mouse models of SMA have demonstrated that not all Motor Neurons are equally susceptible to the disease, revealing that other populations of Neurons can also be affected. Here, we have extended investigations of selective vulnerability of Neuronal populations in the spinal cord of SMA mice to include comparative assessments of Alpha Motor Neuron (α-MN) and gamma Motor Neuron (γ-MN) pools, as well as other populations of cholinergic Neurons. Immunohistochemical analyses of late-symptomatic SMA mouse spinal cord revealed that numbers of α-MNs were significantly reduced at all levels of the spinal cord compared with controls, whereas numbers of γ-MNs remained stable. Likewise, the average size of α-MN cell somata was decreased in SMA mice with no change occurring in γ-MNs. Evaluation of other pools of spinal cord cholinergic Neurons revealed that pre-ganglionic sympathetic Neurons, central canal cluster interNeurons, partition interNeurons and preganglionic autonomic dorsal commissural nucleus Neuron numbers all remained unaffected in SMA mice. Taken together, these findings indicate that α-MNs are uniquely vulnerable among cholinergic Neuron populations in the SMA mouse spinal cord, with γ-MNs and other cholinergic Neuronal populations being largely spared.

Victor Dubowitz - One of the best experts on this subject based on the ideXlab platform.

  • Molecular studies of spinal muscular atrophy
    Neuromuscular disorders : NMD, 1991
    Co-Authors: Kay E. Davies, N.h. Thomas, R. J. Daniels, Victor Dubowitz
    Abstract:

    Spinal muscular atrophy (SMA) is inherited as an autosomal recessive disorder which presents as a severe, intermediate or mild condition. The disease selectively affects the Alpha Motor Neuron but nothing is as yet known about the underlying biochemical defect. Recent genetic studies have mapped all three types of SMA to the same region of human chromosome 5 (5q11.2-q13.3) raising the possibility that the mutations may be allelic. Polymorphic DNA markers have been characterised which are suitable for prenatal diagnosis. This is the first step in the isolation of the mutant gene (or genes) involved in this disorder.

Serkan Uslu - One of the best experts on this subject based on the ideXlab platform.

  • Modified Motor unit number index (MUNIX) algorithm for assessing excitability of Alpha Motor Neuron in spasticity
    Clinical neurophysiology practice, 2018
    Co-Authors: Serkan Uslu, Tunca Nüzket, Hilmi Uysal
    Abstract:

    Abstract Objective The understanding of the spasticity mechanism is still a problem in the literature, as its definition can be made on the basis of more than one parameter. Therefore, we studied Alpha Motor Neuron excitability, dynamic changes based on force production, and patellar tendon (T) reflex in spasticity and healthy control groups. Methods Alpha Motor Neuron excitability, force production, and patellar T reflex were evaluated through three different test protocols. Motor Unit Number Index (MUNIX) measurement was applied for understanding Motor Neuron pool properties in the first protocol. Voluntary force production and patellar T reflex parameters were evaluated by voluntary force production and triggering patellar T reflex. Twenty spasticity and 20 healthy volunteers participated in the study. Results In the spasticity group, both MUNIX numbers and Motor Unit Size Index (MUSIX) numbers were lower than those in the control group. The results for the Ideal Case Motor Unit Count (ICMUC) parameter show that there is no significant difference between spasticity and healthy individuals for low-level contractions, whereas there is a significant difference for high-level contractions (p  Conclusion Spasticity and healthy subjects can be distinguished easily and clearly by evaluating the changes in both kinesiological and electrophysiological findings and the decreasing threshold in the Alpha Motor Neuron pool. Significance This study shows that such combined methods, which allow the evaluation of the Alpha Motor Neuron pool, as well as kinesiological and electrophysiological parameters, are tools that cannot be overlooked in understanding spasticity.

  • O121 Alpha Motor Neuron excitability and force generation in spasticity
    Clinical Neurophysiology, 2017
    Co-Authors: Serkan Uslu, Tunca Nüzket, Can Ozcan, Suha Yagcioglu, Hilmi Uysal
    Abstract:

    Objective The aim of this study was to evaluate the Motor unit number, voluntary and reflex force produced by Alpha Motor Neuron excitability in spasticity. For this purpose, electrophysiological and dynamic measurements were taken from spasticity cases and healthy participants. Method Patient group consisted of 20 spasticity and healthy group consisted of 20 healthy individuals. The force values produced by triggering the Patella T reflex were calculated via the acceleration sensor. For calculation of the force at the Patellar Tendon during Patellar Reflex triggered force production, we used fundamental principle of leverage with acceleration sensor data. The force obtained by this measurement is defined as reflexive force. Motor unit numbers of participants were evaluated according to MUNIX algorithm. Results There were statistically significant differences between the spasticity cases and healthy control group both for Motor unit number and the high level voluntary force production and the force generated by reflex triggering ( p Discussion This study shows that such combined methods, which allows the evaluation of the Alpha Motor Neuron pool, as well as the kinesiological and electrophysiological parameters, are tools that cannot be overlooked in understanding spasticity. Conclusion Motor unit number and force generation were evaluated in spasticity and healthy individuals and statistically significance differences in these features were obtained between two groups. Significance Motor unit number of rectus femoris muscle in spasticity is measured by MUNIX algorithm. Evaluating of voluntary and reflex-generated force with Motor unit number have a potential tool for investigating spasticity.

Rachael A Powis - One of the best experts on this subject based on the ideXlab platform.

  • selective loss of Alpha Motor Neurons with sparing of gamma Motor Neurons and spinal cord cholinergic Neurons in a mouse model of spinal muscular atrophy
    Journal of Anatomy, 2016
    Co-Authors: Rachael A Powis, Thomas H Gillingwater
    Abstract:

    Spinal muscular atrophy (SMA) is a neuromuscular disease characterised primarily by loss of lower Motor Neurons from the ventral grey horn of the spinal cord and proximal muscle atrophy. Recent experiments utilising mouse models of SMA have demonstrated that not all Motor Neurons are equally susceptible to the disease, revealing that other populations of Neurons can also be affected. Here, we have extended investigations of selective vulnerability of Neuronal populations in the spinal cord of SMA mice to include comparative assessments of Alpha Motor Neuron (α-MN) and gamma Motor Neuron (γ-MN) pools, as well as other populations of cholinergic Neurons. Immunohistochemical analyses of late-symptomatic SMA mouse spinal cord revealed that numbers of α-MNs were significantly reduced at all levels of the spinal cord compared with controls, whereas numbers of γ-MNs remained stable. Likewise, the average size of α-MN cell somata was decreased in SMA mice with no change occurring in γ-MNs. Evaluation of other pools of spinal cord cholinergic Neurons revealed that pre-ganglionic sympathetic Neurons, central canal cluster interNeurons, partition interNeurons and preganglionic autonomic dorsal commissural nucleus Neuron numbers all remained unaffected in SMA mice. Taken together, these findings indicate that α-MNs are uniquely vulnerable among cholinergic Neuron populations in the SMA mouse spinal cord, with γ-MNs and other cholinergic Neuronal populations being largely spared.