Análisis biomecánico para confirmar el diagnóstico en neurorrehabilitación

[ES] En los pacientes con lesión medular cervical (LMC) se ve comprometida en mayor o menor medida la fuerza de las extremidades superiores, lo que se traduce en dependencia para las AVDs. Si la lesión es incompleta, puede preservarse la capacidad de marcha. En este contexto, resulta difícil realizar un diagnóstico clínico correcto y los equipos de fotogrametría constituyen una herramienta de gran valor para objetivar las secuelas motoras. El objetivo es presentar la metodología biomecánica de miembros superiores e inferiores aplicada a un caso de estudio. Se trata de un paciente varón de 61 años que padeció una LMC incompleta de etiología traumática que, previamente, había sufrido un TCE. Mediante fotogrametría se analizaron los recorridos articulares de la cadera, rodilla y tobillo durante los ciclos de la marcha y del hombro, codo y muñeca, así como una serie de índices cinemáticos descriptores del movimiento del miembro superior. Se obtuvo un patrón de marcha muy simétrico en ambos miembros inferiores. Sin embargo, la funcionalidad global y los índices de destreza en ambos miembros superiores presentaron una marcada asimetría entre ellos. Las herramientas biomecánicas evidencian aspectos del control motor no fácilmente visibles con los tests clínicos y que perfeccionan el diagnóstico de los casos complejos.[EN] In cervical spinal cord injured (SCI) patients, upper limbs strength is affected to a greater or lesser extent, producing dependence on the execution of ADLs. If the lesion is incomplete, the gait ability can be preserved. In this context, it is difficult to make a correct clinical diagnosis and the photogrammetry equipments constitute a tool of great value to determine with objectivity motor sequelae. The objective is to present the biomechanics methodology of upper and lower limbs applied to a case study. It is a 61- year-old male patient who suffered an incomplete SCI of traumatic etiology that had previously suffered a traumatic brain injury. Through photogrammetry, the range of motion of the hip, knee and ankle joints were analyzed during the cycles of the gait and the shoulder, elbow and wrist joints, as well as a series of kinematic indices describing the ability and dexterity of the upper limb movement. A very symmetrical gait pattern was obtained in both lower limbs. However, overall functionality and skill indices in both upper limbs present a high asymmetry between them. Biomechanical tools demonstrate aspects of motor control not easily visible with clinical tests and perfect diagnosis of complex casesDe Los Reyes Guzmán, A.; López-Dolado, E.; Pérez-Rizo, E.; Lozano-Berrio, V.; Gil-Agudo, A.; Del Ama Espinosa, A. (2019). Análisis biomecánico para confirmar el diagnóstico en neurorrehabilitación. En 11º Simposio CEA de Bioingeniería. Editorial Universitat Politècnica de València. 49-63. https://doi.org/10.4995/CEABioIng.2019.10045OCS496

Fusion of virtual reality and brain-machine interfaces for the assessment and rehabilitation of patients with spinal cord injury

La presente tesis está centrada en la utilización de nuevas tecnologías (Interfaces Cerebro-Máquina y Realidad Virtual). En la primera parte de la tesis se describe la definición y la aplicación de un conjunto de métricas para evaluar el estado funcional de los pacientes con lesión medular en el contexto de un sistema de realidad virtual para la rehabilitación de los miembros superiores. El objetivo de este primer estudio es demostrar que la realidad virtual puede utilizarse, en combinación con sensores inerciales para rehabilitar y evaluar simultáneamente. 15 pacientes con lesión medular llevaron a cabo 3 sesiones con el sistema de realidad virtual Toyra y se aplicó el conjunto definido de métricas a las grabaciones obtenidas con los sensores inerciales. Se encontraron correlaciones entre algunas de las métricas definidas y algunas de las escalas clínicas utilizadas con frecuencia en el contexto de la rehabilitación. En la segunda parte de la tesis se ha combinado una retroalimentación virtual con un estimulador eléctrico funcional (en adelante FES, por sus siglas en inglés Functional Electrical Stimulator), ambos controlados por un Interfaz Cerebro-Máquina (BMI por sus siglas en inglés Brain-Machine Interface), para desarrollar un nuevo tipo de enfoque terapéutico para los pacientes. El sistema ha sido utilizado por 4 pacientes con lesión medular que intentaron mover sus manos. Esta intención desencadenó simultáneamente el FES y la retroalimentación virtual, cerrando la mano de los pacientes y mostrándoles una fuente adicional de retroalimentación para complementar la terapia. Este trabajo es, de acuerdo al estado del arte revisado, el primero que integra BMI, FES y realidad virtual como terapia para pacientes con lesión medular. Se han obtenido resultados clínicos prometedores por 4 pacientes con lesión medular después de realizar 5 sesiones de terapia con el sistema, mostrando buenos niveles de precisión en las diferentes sesiones (79,13% en promedio). En la tercera parte de la tesis se ha definido una nueva métrica para estudiar los cambios de conectividad cerebral en los pacientes con lesión medular, que incluye información de las interacciones neuronales entre diferentes áreas. El objetivo de este estudio ha sido extraer información clínicamente relevante de la actividad del EEG cuando se realizan terapias basadas en BMI

The role of inter-enlargement propriospinal neurons in locomotion following spinal cord injury.

The focus of this dissertation is to explore the functional role of two anatomically-defined pathways in the adult rat spinal cord before and after spinal cord injury (SCI). To do this, a TetOn dual virus system was used to selectively and reversibly silence neurons with cell bodies at spinal segment L2 and projections to spinal segment C6 (long ascending propriospinal neurons, LAPNs) and neurons that originate in the C6 spinal segment and terminate at L2 spinal segment (long descending propriospinal neurons, LDPNs). This dissertation is divided into five chapters. Chapter One provides background information regarding spinal cord injury, locomotion, and a brief introduction to propriospinal neurons. Chapter Two details the functional consequences of silencing LAPNs and LDPNs in uninjured animals, with specific regard to sensory context during overground locomotion. Chapter Three describes the consequences of silencing LAPNs following a mild/moderate spinal cord contusion injury. Spinal cord injury (SCI) fundamentally affects the ability to maintain patterned weight-supported stepping. Chapter Four focuses on the functional outcomes of silencing the reciprocal descending inter-enlargement pathway, LDPNs, after mild/moderate spinal cord contusion injury. Finally, Chapter Five compares the differential roles of LAPNs and LDPNs in left-right coordination prior to injury, especially in a sensory context-dependent manner. A section of this chapter is devoted to a recap of injured data for both LAPN and LDPN silencing post-injury and attempts to place this work in context with other studies whose focus is on propriospinal pathways after SCI

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

Management of Degenerative Cervical Myelopathy and Spinal Cord Injury

The present Special Issue is dedicated to presenting current research topics in DCM and SCI in an attempt to bridge gaps in knowledge for both of the two main forms of SCI. The issue consists of fourteen studies, of which the majority were on DCM, the more common pathology, while three studies focused on tSCI. This issue includes two narrative reviews, three systematic reviews and nine original research papers. Areas of research covered include image studies, predictive modeling, prognostic factors, and multiple systemic or narrative reviews on various aspects of these conditions. These articles include the contributions of a diverse group of researchers with various approaches to studying SCI coming from multiple countries, including Canada, Czech Republic, Germany, Poland, Switzerland, United Kingdom, and the United States

Gait impairment in cervical spondylotic myelopathy: Analysis, impact on function, and effect of surgical intervention

Chest pain is one of the most frequent complaints in medical settings, yet more than half of cases have no detectable cause. Once a cardiac cause has been excluded, patients are typically discharged with a label of non-cardiac chest pain (NCCP). Patients with NCCP have been shown to have poor outcomes in terms of continued symptoms, distress, and continuing concern about heart disease. In addition, NCCP represents a significant burden to health services. The aetiology and management of NCCP is under-researched and poorly understood. This study sought to examine the predictors of persistent pain and health service use for patients in whom a cardiac diagnosis had been excluded. It also sought to explore how patients interpreted their symptoms in the context of normal test results, and the impact of their experiences with health services on these interpretations. A mixed-methods design was adopted. A prospective cohort study was initially conducted with 145 participants with chest pain who attended exercise stress testing and had normal test results. At one-year follow-up, 69% reported continued pain. In addition, nearly half of participants had returned to their general practitioner and one in ten had attended the emergency department for the investigation of chest pain. In logistic regression analyses, the variables heartburn, pain precipitated by movement, cardiac anxiety, illness perceptions, and lack of communication about test results were predictive of persistent chest pain. When participants with continued chest pain were categorised into persistent healthcare users and non-persistent healthcare users, these variables were predominantly associated with participants with persistent health service use for chest pain. In addition, a number of psychological variables including anxiety and depression distinguished the persistent service users. Employment appeared to be a protective factor against persistent pain and related service use. A small sample of participants from this cohort was interviewed in a qualitative study informed by the principles of Interpretative Phenomenological Analysis (IPA). Analysis revealed three predominant themes: 1) the disempowerment of normal test results; 2) limbo - the inner struggle of negating and relating to potential causes; and 3) the inadequacy of healthcare to validate and care for symptoms. The dynamic, complex process of interpreting symptoms and deciding whether to seek healthcare was illuminated. The results indicate that interventions targeting the assessment of a potential gastro-oesophageal or musculoskeletal cause and the reduction of cardiac anxiety are likely to improve outcomes in these patients. Improved communication with patients is also indicated. Psychological factors appear to drive persistent service use and interventions targeting these are likely to reduce medical costs. Patients with NCCP are not a homogenous patient group and an individualised, stepped-care approach to management appears to be warranted

Reversible silencing of spinal neurons unmasks a left-right coordination continuum.

This dissertation is focused on dissecting the functional role of two anatomically-defined pathways in the adult rat spinal cord. A TetOn dual virus system was used to selectively and reversibly induce enhanced tetanus neurotoxin expression in L2 neurons that project to L5 (L2-L5) or C6 (long ascending propriospinal neurons, LAPNs). Results focus on the changes observed during overground locomotion. The dissertation is divided into four chapters. Chapter One is a focused introduction to locomotion, including its broad description, the central mechanisms of its expression, how genetic-based approaches defined these mechanisms, and the limitations in these approaches. It concludes with details of the silencing paradigm used here and a summary of the main findings. Chapter Two describes the functional consequences of silencing L2-L5 interneurons. The focus is on selective disruption of hindlimb coordination during overground locomotion, revealing a continuum from walk to hop. These changes are independent of speed, step frequency, and other spatiotemporal features of gait. Left-right alternation was restored during swimming and stereotypic exploration, suggesting a task-specific role. Silencing L2-L5 interneurons partially uncoupled the hindlimbs, allowing spontaneous shifts in coordination on a step-by-step basis. It is proposed this pathway distributes temporal information for left-right hindlimb alternation, securing effective coordination in a context-dependent manner. Chapter Three focuses on the consequences of silencing LAPNs.Three patterns of interlimb coupling are disrupted: left-right forelimb, left-right hindlimb, and contralateral hindlimb-forelimb coordination. Observed again was a context-dependent continuum from walk-to-hop, irrespective of step frequency, speed, and the salient features that define locomotion. However, instead of spontaneous shifts in coordination as observed from L2-L5 interneuron silencing, the breadth of coupling patterns expressed were maintained on a step-by-step basis. It is proposed that this ascending, inter-enlargement pathway distributes temporal information required for left-right alternation at the shoulder and pelvic girdles in a context-dependent manner. Collectively, these data suggest that L2-L5 interneurons and LAPNs are key pathways that distribute left-right patterning information throughout the neuraxis. The functional role(s) of these pathways are exquisitely gated to the context at hand, suggesting that the locomotor circuitry undergoes functional reorganization thereby endowing or masking the silencing-induced disruptions to interlimb coordination