A study to correlate the hand function with the physical structure and physiological function of the cervical spinal cord in cervical myelopathy.

Law Ka Pui, Karlen.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 159-170).Abstracts in English and Chinese.Declaration --- p.1Abstract --- p.iiAcknowledgement --- p.viiAbbreviations --- p.viiiList of Figures --- p.xList of Tables --- p.xivContents --- p.xviChapter Chapter One - --- IntroductionChapter 1.1 --- The Cervical SpineChapter 1.1.1 --- Anatomy of Typical Cervical Vertebrae --- p.1Chapter 1.1.1.1 --- The Vertebral BodyChapter 1.1.1.2 --- The Vertebral (Neural) ArchChapter 1.1.1.3 --- The Vertebral ProcessesChapter 1.1.1.4 --- The ForaminaChapter 1.1.2 --- Anatomy of Atypical Cervical Vertebrae --- p.6Chapter 1.1.3 --- The Cervical Region of Spinal Cord --- p.8Chapter 1.1.3.1 --- Structure of the Spinal CordChapter 1.1.3.1.1 --- Gray MatterChapter 1.1.3.1.2 --- White MatterChapter 1.1.4 --- The Crucial Ascending Tracts in the White Column --- p.11Chapter 1.1.4.1 --- Tracts in Dorsal (Posterior) ColumnChapter 1.1.4.2 --- Tracts in the Lateral ColumnChapter 1.1.4.2.1 --- Posterior Spinocerebellar TractChapter 1.1.4.2.2 --- Anterior Spinocerebellar TractChapter 1.1.4.2.3 --- Lateral Spinothalamic TractChapter 1.1.4.2.4 --- Postero-lateral Tract of LissauerChapter 1.1.4.2.5 --- Spino-olivary TractChapter 1.1.4.3 --- Tracts in the Ventral (Anterior) ColumnChapter 1.1.5 --- The Main Descending Tracts of White Column --- p.14Chapter 1.1.5.1 --- Tracts in the Dorsal ColumnChapter 1.1.5.2 --- Tracts in the Lateral ColumnChapter 1.1.5.2.1 --- Lateral Corticospinal TractChapter 1.1.5.2.2 --- Rubrospinal TractChapter 1.1.5.3 --- Tracts in Ventral ColumnChapter 1.1.5.3.1 --- Anterior Corticospinal TractChapter 1.1.5.3.2 --- Vestibulospinal Tract and Reticulospinal TractChapter 1.2 --- The Cervical Spinal Nerve RootsChapter 1.2.1 --- The Dorsal Roots --- p.16Chapter 1.2.2 --- The Ventral Roots --- p.18Chapter 1.2.3 --- The Relation between the Afferent and Efferent Nerve Roots --- p.19Chapter 1.3 --- Cervical MyelopathyChapter 1.3.1 --- Cause of Cervical Spondylotic Myelopathy --- p.21Chapter 1.3.2 --- Clinical Symptoms of Cervical Myelopathy --- p.23Chapter 1.4 --- Hypothesis --- p.25Chapter Chapter Two - --- MethodologyChapter 2.1 --- Inclusive Criteria of the Study --- p.27Chapter 2.2 --- Magnetic Resonance Imaging of the Cervical Spine --- p.29Chapter 2.2.1 --- The Setup of the MRIChapter 2.2.2 --- Subject PreparationChapter 2.2.3 --- Identification of the Most Stenotic Region in the Cervical SpineChapter 2.2.4 --- Measurement of the Most Stenotic Cervical Spinal Cord and CanalChapter 2.2.4.1 --- Dimensions of the Spinal Cord and Canal in Sagittal PlaneChapter 2.2.4.2 --- Dimensions of the Spinal Cord and Canal in Coronal PlaneChapter 2.2.4.3 --- Dimensions of the Spinal Cord and Canal in Horizontal PlaneChapter 2.2.4.4 --- Compression Ratio of the Sagittal and Coronal DimensionChapter 2.2.5 --- Somatosensory Evoked Potential (SEP) EvaluationChapter 2.2.6 --- Choice of StimulationChapter 2.2.7 --- Reception of SignalsChapter 2.2.7.1 --- Erb's PointChapter 2.2.7.2 --- Sensory Cortex ReceptionChapter 2.2.7.3 --- Subject PreparationChapter 2.3 --- Upper Limb Functional Assessment --- p.44Chapter 2.3.1 --- JOA Score for Cervical MyelopathyChapter 2.3.1.1 --- Upper Extremity FunctionChapter 2.3.1.2 --- Lower Extremity FunctionChapter 2.3.1.3 --- Sensory DisturbanceChapter 2.3.1.4 --- Urinary FunctionChapter 2.3.2 --- Jebsen Hand Function TestChapter 2.3.2.1 --- Sub-test 2 - Card Turning TestChapter 2.3.2.2 --- Sub-test 3 - Small Object Pinching TestChapter 2.3.2.3 --- Sub-test 4 - Simulated Feeding TestChapter 2.3.2.4 --- Sub-test 5 - Stacking Checkers TestChapter 2.3.2.5 --- Sub-test 6 - Large Light Object Picking TestChapter 2.3.2.6 --- Sub-test 7 - Heavy Large Object Picking TestChapter 2.3.3 --- The Purdue Pegboard TestChapter 2.3.3.1 --- Sub-test 1 - Dominant HandChapter 2.3.3.2 --- Sub-test 2 - Non-dominant HandChapter 2.3.3.3 --- Sub-test 3 - Both HandsChapter 2.3.3.4 --- Sub-test 4 - AssemblyChapter 2.4 --- Statistical Analysis Method --- p.74Chapter Chapter Three - --- ResultsChapter 3.1 --- Subject Distribution --- p.76Chapter 3.2 --- Magnetic Resonance Imaging Measurement --- p.82Chapter 3.3 --- Somatosensory Evoked Potentials Recording --- p.94Chapter 3.4 --- JOA (Cervical) Scoring --- p.96Chapter 3.5 --- Jebsen Hand Function Test Measurement --- p.101Chapter 3.6 --- Purdue Pegboard Test Measurement --- p.105Chapter 3.7 --- Statistical Analysis Findings --- p.107Chapter 3.8 --- Summary --- p.132Chapter Chapter Four - --- DiscussionChapter 4.1 --- Magnetic Resonance Imaging Measurement --- p.134Chapter 4.1.1 --- Cervical Myelopathy Subjects has Small Spinal Cord and CanalChapter 4.2 --- Somatosensory Evoked Potential of the Median Nerve --- p.140Chapter 4.2.1 --- The Latencies were Preserved in Most of the SubjectsChapter 4.3 --- Cervical Cord Compression Affects the Hand Function Significantly --- p.143Chapter 4.3.1 --- Fine Finger Dexterity Deficiency is a Significant Clinical Symptoms of Cervical Myelopathy SubjectsChapter 4.3.2 --- Deficiency in Manual Dexterity is another Significant Clinical Symptoms of Cervical Myelopathy SubjectsChapter Chapter Five - --- Summary and Conclusion --- p.153Chapter Chapter Six - --- Further StudiesChapter 6.1 --- Modification in the Sample Recruitment --- p.157Chapter 6.2 --- Modification in Assessment Tools and Procedures --- p.158Bibliography --- p.15

Corticospinal excitability, mental rotation task, motor performance and disability in subjects with musculoskeletal disorders of the wrist and hand

L'objectif de cette thèse était de démontrer la présence de modifications des processus sensorimoteurs du système nerveux central (excitabilité corticospinale et schéma corporel tels que mesurés avec la Tâche de Reconnaissance de la Latéralité des Images droite gauche (TRLI)) chez des participants ayant des désordres musculosquelettiques au poignet et à la main. Un deuxième objectif était de déterminer la relation entre les changements de ces processus sensorimoteurs corticaux et des mesures sensorielles, de la fonction motrice, d'incapacité autodéclarée, de la douleur et des facteurs psychosociaux liés à la douleur. Une étude observationnelle transversale a d'abord été menée pour mesurer l'excitabilité corticospinale des muscles de la main en utilisant la stimulation magnétique transcrânienne et la TRLI chez des participants en santé et des participants présentant des douleurs chroniques au poignet et à la main. L’excitabilité corticospinale du muscle court abducteur du pouce de la main affectée était augmentée chez les participants présentant une douleur chronique et ces changements étaient significativement corrélés avec l'intensité de la douleur, l'incapacité autodéclarée, et négativement corrélés avec l'excitabilité motoneuronale. Des différences de performances sur le TRLI, à la fois pour la précision et le temps de réaction, ont également été trouvées entre les participants du groupe contrôle et les participants avec douleur. Dans une deuxième étude transversale, le TRLI, des mesures de motricité, sensibilité et des fonctions cognitives ont été administrées à soixante et un participants présentant des désordres musculosquelettiques du poignet ou de la main droite. Les modèles de régression linéaire multiple ont révélé que la prise de médicaments pour contrer la douleur, la participation à des activités (sociales, professionnelles, domestiques et récréatives), la discrimination tactile de deux points et le niveau de performance motrice expliquent les performances au TRLI. Les participants ayant pris des médicaments pour la douleur la journée de l’évaluation avaient une performance diminuée sur la précision et le temps de réaction sur le TRLI pour la main droite (affectée). Ces participants présentaient aussi une sévérité de douleur et d'incapacité plus élevée et une diminution de fonctions cognitives et motrices plus élevée que le reste des participants avec douleur qui ont été évalués. Dans l’ensemble, ces résultats suggèrent que les participants présentant des désordres musculosquelettiques hétérogènes du poignet ou de la main montrent des changements des processus sensorimoteurs corticaux. Alors que l'excitabilité corticospinale semble être liée à l'intensité de la douleur et à l’incapacité autodéclarée, le TRLI peut être associé à une confluence de facteurs (sensoriels, moteurs, cognitifs-affectifs et comportementaux). Ces résultats suggèrent aussi que les changements sensorimoteurs corticaux ne sont pas simplement le résultat du désordre musculosquelettique, mais impliquent plutôt une interaction complexe entre la douleur, les processus sensorimoteurs et cognitivo-affectifs, et peut-être aussi des réponses comportementales à l’atteinte musculosquelettique. Les résultats fournissent également des informations précieuses à propos des personnes qui pourraient bénéficier d'interventions orientées vers le rétablissement des processus centraux en plus des traitements de réadaptation axés sur les structures périphériques.The objective of the thesis was to investigate for the presence of changes in cortical sensorimotor processes (corticospinal excitability and the body schema measured with the Left Right Judgment Task (LRJT) performance), in participants with Musculoskeletal Disorders (MSD) of the wrist/hand. A second objective was to determine the relationship between these cortical sensorimotor processes and measures of sensory and hand motor function, disability, pain and pain related psychosocial factors. First, an observational cross-sectional study was conducted to explore corticospinal excitability of muscles in the hand and cortical sensorimotor processes, utilizing transcranial magnetic stimulation and the LRJT in healthy, pain-free participants and participants with chronic wrist/hand pain. Increased corticospinal excitability for the abductor pollicis brevis of the affected hand in participants with chronic MSD of the wrist/hand was found and these changes were significantly correlated with pain intensity, disability, and negatively correlated with spinal motoneuronal excitability. Differences in LRJT performance were also found between healthy control participants and participants with pain for both LRJT accuracy and reaction time. In a second cross-sectional study, LRJT performance, motor, sensory and cognitive assessments were performed on sixty-one participants with MSD of the right dominant wrist/hand. The multiple linear regression model revealed that taking pain medication, participating in (social, work, household and leisure) activities, two-point discrimination, and motor performance explained performance on the LRJT of the right (affected) hand. Those participants that took pain medication on the day of the evaluation performed more poorly on both LRJT accuracy and reaction time of the right (affected) hand. These participants had higher pain severity and disability scores and decreased cognitive and motor function. Collectively, these results suggest that participants with heterogeneous MSD of the wrist/hand display altered cortical sensorimotor processes. Whereas corticospinal excitability appears to be related to pain intensity and disability, the LRJT may be associated with a confluence of factors (sensory, motor, cognitive-affective, and behaviours). These findings suggest that cortical sensorimotor changes do not simply appear to be the result of the condition but involve a complex interaction between pain, sensorimotor and cognitive-affective processes, and possibly behavioural responses to the condition. The findings also provide valuable insight as to those persons who may benefit from cognitively directed interventions in addition to peripherally driven rehabilitative treatments

Non-invasive multi-channel electrophysiology of the human spinal cord: Assessing somatosensory processing from periphery to cortex

The spinal cord is of fundamental importance for somatosensory processing and plays a significant role in various pathologies, such as chronic pain. However, knowledge on spinal cord processing in humans is limited due to the vast technical challenges involved in its investigation via non-invasive recording approaches. Here, we aim to address these challenges by developing an electrophysiological approach – based on a high-density electrode-montage – that allows for characterizing spinal cord somatosensory evoked potentials (SEPs) and combining this with concurrent recordings of the spinal cord’s input (peripheral nerve action potentials) and output (SEPs in brainstem and cortex). In two separate experiments, we first methodologically validate the approach (including replication and robustness analyses) and then assess its application in the context of a neuroscientific question (integrative processes along the neural hierarchy). Critically, we demonstrate the benefits of multi-channel recordings in terms of enhancing sensitivity via spatial filtering, which also allows for obtaining spinal cord SEPs at the single-trial level. We make use of this approach to demonstrate the feasibility of recording spinal cord SEPs in low-signal scenarios (single-digit stimulation) and – most importantly – to provide evidence for bottom-up signal integration already at the level of the spinal cord. Taken together, our approach of concurrent multi-channel recordings of evoked responses along the neural hierarchy allows for a comprehensive assessment of the functional architecture of somatosensory processing at a millisecond timescale

Paresthesia

Paresthesias are spontaneous or evoked abnormal sensations of tingling, burning, pricking, or numbness of a person's skin with no apparent long-term physical effect. Patients generally describe a lancinating or burning pain, often associated with allodynia and hyperalgesia. The manifestation of paresthesia can be transient or chronic. Transient paresthesia can be a symptom of hyperventilation syndrome or a panic attack, and chronic paresthesia can be a result of poor circulation, nerve irritation, neuropathy, or many other conditions and causes. This book is written by authors that are respected in their countries as well as worldwide. Each chapter is written so that everyone can understand, treat and improve the lives of each patient

Spinal Cord Injury and Transcutaneous Spinal Cord Stimulation

Recent research of epidural and transcutaneous electrical spinal cord stimulation has demonstrated unprecedented improvements in motor function thought to be irreversibly lost due to chronic, severe spinal cord injury. Studies in parallel assess these methods for spasticity management as an alternative to medications that are often accompanied by deleterious side effects. As a noninvasive intervention, transcutaneous spinal cord stimulation holds the great potential to find its way into wide clinical application. Its firm establishment and lasting acceptance as clinical practice in spinal cord injury will not only hinge on the demonstration of safety and efficacy, but also on the delineation of a conceptual framework of the underlying physiological mechanisms. This will also require advancing our understanding of immediate and temporary effects of transcutaneous spinal cord on neuronal circuits in the intact and injured spinal cord. The purpose of this collection of papers is to bring together peers in the field to share—and eventually fuse—their pertinent research into current neurorehabilitation practice by providing a clinical perspective and novel insights into the underlying mechanisms

VALIDATION OF A MODEL OF SENSORIMOTOR INTEGRATION WITH CLINICAL BENEFITS

Healthy sensorimotor integration – or how our touch influences our movements – is critical to efficiently interact with our environment. Yet, many aspects of this process are still poorly understood. Importantly, several movement disorders are often considered as originating from purely motor impairments, while a sensory origin could also lead to a similar set of symptoms. To alleviate these issues, we hereby propose a novel biologically-based model of the sensorimotor loop, known as the SMILE model. After describing both the functional, and the corresponding neuroanatomical versions of the SMILE, we tested several aspects of its motor component through functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS). Both experimental studies resulted in coherent outcomes with respect to the SMILE predictions, but they also provided novel scientific outcomes about such broad topics as the sub-phases of motor imagery, the neural processing of bodily representations, or the extend of the role of the extrastriate body area. In the final sections of this manuscript, we describe some potential clinical application of the SMILE. The first one presents the identification of plausible neuroanatomical origins for focal hand dystonia, a yet poorly understood sensorimotor disorder. The last chapter then covers possible improvements on brain-machine interfaces, driven by a better understanding of the sensorimotor system. -- La façon dont votre sens du toucher et vos mouvements interagissent est connue sous le nom d’intégration sensorimotrice. Ce procédé est essentiel pour une interaction normale avec tout ce qui nous entoure. Cependant, plusieurs aspects de ce processus sont encore méconnus. Plus important encore, l’origine de certaines déficiences motrices encore trop peu comprises sont parfois considérées comme purement motrice, alors qu’une origine sensorielle pourrait mener à un même ensemble de symptômes. Afin d’améliorer cette situation, nous proposons ici un nouveau modèle d’intégration sensorimotrice, dénommé « SMILE », basé sur les connaissances de neurobiologie actuelles. Dans ce manuscrit, nous commençons par décrire les caractéristiques fonctionnelles et neuroanatomiques du SMILE. Plusieurs expériences sont ensuite effectuées, via l’imagerie par résonance magnétique fonctionnelle (IRMf), et la stimulation magnétique transcranienne (SMT), afin de tester différents aspects de la composante motrice du SMILE. Si les résultats de ces expériences corroborent les prédictions du SMILE, elles ont aussi mis en évidences d’autres résultats scientifiques intéressants et novateurs, dans des domaines aussi divers que les sous-phases de l’imagination motrice, les processus cérébraux liés aux représentations corporelles, ou encore l’extension du rôle de l’extrastriate body area. Dans les dernières parties de ce manuscrit, nous dévoilons quelques applications cliniques potentielles de notre modèle. Nous utilisons le SMILE afin de proposer deux origines cérébrales plausibles de la dystonie focale de la main. Le dernier chapitre présente comment certaines technologies existantes, telles que les interfaces cerveaux-machines, pourraient bénéficier d’une meilleure compréhension du système sensorimoteur