ABSTRACT
The cognitive-motor interference (CMI) produced by simultaneous performance of a cognitive and a motor task has been proposed as a marker of real-life impairment of people with Multiple Sclerosis (pwMS), yet there is no consensus on the dual task (DT) procedure. This study aimed to compare DT performance of pwMS and healthy controls (HC) under different instructions and to examine its association with neuropsychological and clinical variables. PwMS (N = 23; relapsing-remitting course) and HC (N = 24) completed the cognitive (Verbal Fluency) and motor (walking) tasks under three conditions: independently or as single task (ST), both tasks simultaneously at best capacity or double prioritization (DT-DP), and only the cognitive task at best capacity while walking at preferred speed or cognitive prioritization (DT-CP). Compared to HC, pwMS walked significantly slower and produced less correct words under all conditions. The distance walked by pwMS and HC significantly differed between conditions (DT-CP< DT-DP< ST). PwMS produced more words during ST respective to DT-DP and DT-CP, with no difference between both DT conditions. HC showed no differences in cognitive performance between conditions. Motor and cognitive dual-task costs (DTC) were similar between groups. Only in pwMS, the cognitive DTC of DT-DP was different from zero. CMI measures correlated with neuropsychological, symptomatic, physiological (cognitive event-related potentials) and clinical variables. These results suggest that cognitive performance while walking is impaired in pwMS, but not in HC. CMI over cognitive performance might be a potential early marker of cognitive decline in pwMS, which may be enhanced by the instruction to prioritize both tasks in DT.
Subject(s)
Multiple Sclerosis, Relapsing-Remitting/physiopathology , Adult , Cognition , Female , Humans , Male , Middle Aged , Multiple Sclerosis, Relapsing-Remitting/psychology , Psychomotor Performance , Task Performance and AnalysisABSTRACT
El músculo esquelético es un tejido maleable y dinámico capaz de un alto grado de plasticidad con respecto a su configuración histológica. En este sentido, el estudio microscópico es una herramienta importante y esencial para el análisis de los procesos adaptativos −como la hipertrofia o los cambios de tipos de fibras− y la regeneración o reparación del músculo esquelético después de la lesión, en las áreas de la medicina deportiva y la traumatología respectivamente. Mientras que con microscopía óptica se aborda el estudio de los diferentes elementos constitutivos del músculo esquelético y sus relaciones entre sí que determinan la histoarquitectura del órgano, con microscopía electrónica se realiza el análisis ultraestructural que permite relacionar estructura y función de las células individuales. Este artículo ilustra un enfoque pragmático y práctico, en base a la experiencia personal y una revisión de la literatura, desde las condiciones en la obtención y envío de las muestras de músculo esquelético al laboratorio a los procedimientos para prepararlas para su estudio histológico (secciones de criostato, secciones de parafina y microscopía electrónica). Especialmente nos centramos en la descripción del procesado por congelación y recomendaciones a seguir, al ser éste el método ideal para este tejido. El objetivo de este artículo es proporcionar información útil sobre el manejo de muestras de músculo esquelético que se procesan en el laboratorio de histología para lograr resultados óptimos y fiables en los análisis microscópicos y cómo evitar los errores metodológicos que conducen a la aparición de artefactos que pueden llegar a dificultar o invalidar el estudio histológico
Skeletal muscle is a malleable and dynamic tissue capable of a high degree of plasticity in regards to its histological configuration. In this sense, microscopic study is an important and essential tool for the analysis of adaptive processes -such as hypertrophy or changes of fiber types- and the regeneration or repair of skeletal muscle after injury, in the fields of sports medicine and traumatology respectively. While light microscopy addresses the study of the different constitutive elements into the skeletal muscle and their relationships with each other that determine the organ histoarchitecture, with electron microscopy an ultrastructural analysis is carried out that allows to relate the structure and function of the individual cells. This article illustrates a pragmatic and practical approach, based on personal experience and a review of the literature, from the conditions in obtaining and sending samples of skeletal muscle to the laboratory to the procedures to prepare them for histological study (sections of cryostat, paraffin sections and electron microscopy). Especially we focus on the description of the processing by freezing and recommendations to follow, as this is the ideal method for this tissue. The aim of this article is to provide useful information on the management of skeletal muscle samples that are processed in the histology laboratory to achieve optimal and reliable results in microscopic analyzes and how to avoid methodological errors that lead to the appearance of artifacts that can get to hinder or invalidate the histological study
