Estimulación magnética transcraneal y fisioterapia en la rehabilitación motora de la enfermedad vascular cerebral. Revisión sistemática / Transcranial magnetic stimulation and physiotherapy on motor stroke rehabilitation. Systematic review

OBJETIVO: Realizar una revisión sistemática actualizada y crítica sobre los estudios clínicos que han utilizado la combinación de estimulación magnética transcraneal repetitiva (EMTr) con fisioterapia en pacientes con secuelas de enfermedad vascular cerebral (EVC) para conocer si existen efectos sinérgicos de ambas terapias sobre la función motora. ESTRATEGIA DE BÚSQUEDA Y SELECCIÓN DE ESTUDIOS: Revisión sistemática de estudios clínicos con grupo control. La búsqueda se realizó en las siguientes bases de datos: PubMed, MedLine, DynaMed, EBSCO, Science Direct y Latindex, de 2009 a 2019. Se encontró un total de 184 artículos, y basado en los criterios de inclusión se seleccionó un total de 10 estudios que combinaron fisioterapia con EMTr. SÍNTESIS DE RESULTADOS: Existen pocos estudios en donde se haya combinado la aplicación de EMTr con fisioterapia para la recuperación motora en EVC. Se encontraron diversos puntos de variabilidad en el diseño de los estudios, lo cual dificulta su comparación: número de participantes, tipo de fisioterapia aplicada, parámetros de estimulación, variables de desenlace, etc. Seis estudios demostraron efectos sinérgicos de la EMT + fisioterapia en la función motora en EVC. CONCLUSIONES: Se observaron múltiples puntos de variabilidad metodológica que pueden afectar la comparación entre los estudios. La evidencia disponible parece sugerir un efecto sinérgico de la combinación de EMTr + fisioterapia en la función motora en EVC

OBJECTIVE: To perform an updated and critical systematic review of the clinical studies that have used the combination of repetitive Transcranial Magnetic Stimulation (rTMS) and physiotherapy in patients with sequelae of stroke to establish whether there are synergistic effects of both therapies on motor function SEARCH STRATEGY AND STUDY SELECTION: Systematic review of clinical studies with control group. The search was carried out in the following databases: PubMed, MedLine, DynaMed, EBSCO, Science Direct and Latindex from 2009 to 2019. A total of 184 articles were found and, based on the inclusion criteria, a total of 10 studies were selected who combined physiotherapy with rTMS. SYNTHESIS OF RESULTS: There are few studies where rTMS has been combined with physiotherapy for motor recovery in stroke. Several points of variability were found in the design of the studies, which makes comparison difficult: number of participants, type of physiotherapy applied, stimulation parameters, outcome variables, etc. Six studies showed a synergistic effect of rTMS + physiotherapy on motor function in stroke. CONCLUSIONS: There are several points of methodological variability between studies but the available evidence suggests a possible synergistic effect of rTMS+physiotherapy

Low Serum Tryptophan Levels as an Indicator of Global Cognitive Performance in Nondemented Women over 50 Years of Age.

Aging is a physiological decline process. The number of older adults is growing around the world; therefore, the incidence of cognitive impairment, dementia, and other diseases related to aging increases. The main cellular factors that converge in the aging process are mitochondrial dysfunction, antioxidant impairment, inflammation, and immune response decline, among others. In this context, these cellular changes have an influence on the kynurenine pathway (KP), the main route of tryptophan (Trp) catabolism. KP metabolites have been involved in the aging process and neurodegenerative diseases. Although there are changes in the metabolite levels with age, at this time, there is no study that has evaluated cognitive decline as a consequence of Trp catabolism fluctuation in aging. The aim of this study was to evaluate the relation between the changes in Trp catabolism and cognitive impairment associated with age through KP metabolites level alterations in women over 50 years of age. Seventy-seven nondemented women over 50 years old were examined with a standardized cognitive screening evaluation in Spanish language (Neuropsi), Beck anxiety inventory (BAI), and the geriatric depression scale (GDS). Also, serum levels of Trp, kynurenine (Kyn), kynurenic acid (KYNA), and 3-hydroykynurenine (3-HK) and the glutathione ratio (GSH/GSSG) were measured. Results showed a negative correlation between age and Trp levels and a positive correlation between age and KYNA/Trp and 3-HK/Trp ratios. The level of cognitive impairment showed a significant positive association with age and with kynurenine pathway activation and a significant negative correlation with Trp levels. The GSH/GSSG ratio correlated positively with Trp levels and negatively with Kyn/Trp and 3-HK/Trp ratios. The depression score correlated negatively with Trp and positively with the 3-HK/Trp ratio. We concluded that KP activation increases with age and it is strongly associated with the level of cognition performance in nondemented women over 50 years of age.

Correlación entre las lesiones desmielinizantes y el deterioro de las funciones ejecutivas en una muestra de pacientes mexicanos con esclerosis múltiple / Correlation between demyelinating lesions and executive function decline in a sample of Mexican patients with multiple sclerosis

Antecedentes: La esclerosis múltiple (EM) se caracteriza por una gran diversidad de síntomas neurológicos de entre los cuales el deterioro cognitivo recientemente ha cobrado una especial relevancia. Hasta el momento la evidencia acerca de una correlación entre las características de las lesiones y el deterioro cognitivo específico aún no es concluyente. Objetivo: Analizar si existe una correlación entre las características de las lesiones desmielinizantes y el desempeño de las funciones ejecutivas básicas en estos pacientes. Pacientes y métodos: Se incluyeron 21 pacientes adultos con puntaje de 0-5 en la escala de Kurtzke, sin exacerbaciones de la enfermedad en los 3 meses previos a la evaluación. Se les aplicaron las pruebas de Stroop y elWisconsin Card Sorting Test (WCST). La localización de las lesiones fue determinada por resonancia magnética a través de un observador experto y cegado. Resultados: Las lesiones desmielinizantes se distribuyeron con mayor frecuencia en los lóbulos occipitales y frontales. En el Stroop se observó que a medida que se incrementa la demanda cognitiva en cada sección de la prueba, aumentan el tiempo de reacción y el número de errores. En el WCST, un 33,33% presentó un deterioro medio a moderado. No se encontró una relación entre la lesiones desmielinizantes –localización, tamaño y suma total– y los puntajes de las pruebas aplicadas. Conclusión: En la explicación del deterioro cognitivo en la EM se deben considerar no solo las lesiones desmielinizantes, sino también otros factores biológicos, psicológicos y sociales (AU)

Background: Multiple Sclerosis (MS) is characterised by several neurological symptoms including cognitive impairment, which has recently been the subject of considerable study. At present, evidence pointing to a correlation between lesion characteristics and specific cognitive impairment is not conclusive. Objective: To investigate the presence of a correlation between the characteristics of demyelinating lesions and performance of basic executive functions in a sample of MS patients. Patients and methods: We included 21 adult patients with scores of 0 to 5 on the Kurtzke scale and no exacerbations of the disease in at least 3 months prior to the evaluation date. They completed the Stroop test and the Wisconsin Card Sorting Test (WCST). The location of the lesions was determined using magnetic resonance imaging (MRI) performed by a blinded expert in neuroimaging. Results: Demyelinating lesions were more frequently located in the frontal and occipital lobes. The Stroop test showed that as cognitive demand increased on each of the sections in the test, reaction time and number of errors increased. On the WCST, 33.33% of patients registered as having moderate cognitive impairment. No correlation could be found between demyelinating lesion characteristics (location, size, and number) and patients’ scores on the tests. Conclusion: Explanations of the causes of cognitive impairment in MS should examine a variety of biological, psychological, and social factors instead of focusing solely on demyelinating lesions (AU)

[Correlation between demyelinating lesions and executive function decline in a sample of Mexican patients with multiple sclerosis]. / Correlación entre las lesiones desmielinizantes y el deterioro de las funciones ejecutivas en una muestra de pacientes Mexicanos con esclerosis múltiple.

BACKGROUND: Multiple Sclerosis (MS) is characterised by several neurological symptoms including cognitive impairment, which has recently been the subject of considerable study. At present, evidence pointing to a correlation between lesion characteristics and specific cognitive impairment is not conclusive. OBJECTIVE: To investigate the presence of a correlation between the characteristics of demyelinating lesions and performance of basic executive functions in a sample of MS patients. PATIENTS AND METHODS: We included 21 adult patients with scores of 0 to 5 on the Kurtzke scale and no exacerbations of the disease in at least 3 months prior to the evaluation date. They completed the Stroop test and the Wisconsin Card Sorting Test (WCST). The location of the lesions was determined using magnetic resonance imaging (MRI) performed by a blinded expert in neuroimaging. RESULTS: Demyelinating lesions were more frequently located in the frontal and occipital lobes. The Stroop test showed that as cognitive demand increased on each of the sections in the test, reaction time and number of errors increased. On the WCST, 33.33% of patients registered as having moderate cognitive impairment. No correlation could be found between demyelinating lesion characteristics (location, size, and number) and patients' scores on the tests. CONCLUSION: Explanations of the causes of cognitive impairment in MS should examine a variety of biological, psychological, and social factors instead of focusing solely on demyelinating lesions.

On the antioxidant properties of kynurenic acid: free radical scavenging activity and inhibition of oxidative stress.

Kynurenic acid (KYNA) is an endogenous metabolite of the kynurenine pathway for tryptophan degradation and an antagonist of both N-methyl-D-aspartate (NMDA) and alpha-7 nicotinic acetylcholine (α7nACh) receptors. KYNA has also been shown to scavenge hydroxyl radicals (OH) under controlled conditions of free radical production. In this work we evaluated the ability of KYNA to scavenge superoxide anion (O(2)(-)) and peroxynitrite (ONOO(-)). The scavenging ability of KYNA (expressed as IC(50) values) was as follows: OH=O(2)(-)>ONOO(-). In parallel, the antiperoxidative and scavenging capacities of KYNA (0-150 µM) were tested in cerebellum and forebrain homogenates exposed to 5 µM FeSO(4) and 2.5 mM 3-nitropropionic acid (3-NPA). Both FeSO(4) and 3-NPA increased lipid peroxidation (LP) and ROS formation in a significant manner in these preparations, whereas KYNA significantly reduced these markers. Reactive oxygen species (ROS) formation were determined in the presence of FeSO(4) and/or KYNA (0-100 µM), both at intra and extracellular levels. An increase in ROS formation was induced by FeSO(4) in forebrain and cerebellum in a time-dependent manner, and KYNA reduced this effect in a concentration-dependent manner. To further know whether the effect of KYNA on oxidative stress is independent of NMDA and nicotinic receptors, we also tested KYNA (0-100 µM) in a biological preparation free of these receptors - defolliculated Xenopus laevis oocytes - incubated with FeSO(4) for 1 h. A 3-fold increase in LP and a 2-fold increase in ROS formation were seen after exposure to FeSO(4), whereas KYNA attenuated these effects in a concentration-dependent manner. In addition, the in vivo formation of OH evoked by an acute infusion of FeSO(4) (100 µM) in the rat striatum was estimated by microdialysis and challenged by a topic infusion of KYNA (1 µM). FeSO(4) increased the striatal OH production, while KYNA mitigated this effect. Altogether, these data strongly suggest that KYNA, in addition to be a well-known antagonist acting on nicotinic and NMDA receptors, can be considered as a potential endogenous antioxidant.