La esclerosis múltiple (EM) es una enfermedad que afecta a la mielina o materia blanca del cerebro y de la médula espinal, provocando la aparición de placas escleróticas que impiden el funcionamiento normal de esas fibras nerviosas. La mielina es una sustancia grasa que rodea y aísla los nervios, actuando como la cobertura de un cable eléctrico y permitiendo que los nervios transmitan sus impulsos rápidamente. La velocidad y eficiencia Esclerosis Multiplecon que se conducen estos impulsos permiten realizar movimientos suaves, rápidos y coordinados con poco esfuerzo consciente.CAUSASLa causa de la esclerosis múltiple se desconoce, pero se sospecha que un virus o un antígeno desconocido son los responsables que desencadenan, de alguna manera, una anomalía inmunológica, que suele aparecer a una edad temprana. Entonces el cuerpo, por algún motivo, produce anticuerpos contra su propia mielina. Esto provoca, con el paso del tiempo, la aparición de lesiones de desmielinación y, posteriormente, cicatrices (placas) en distintos puntos del sistema nervioso central. La desmielinación puede afectar a zonas diversas del sistema nervioso central y la distinta localización de las lesiones es la causa de la variabilidad y multiplicidad de los síntomas (trastornos motrices, sensitivos, del lenguaje, del equilibrio, viscerales, etc...).Este mecanismo inmunitario activa los glóbulos blancos (linfocitos) del torrente sanguíneo, que entran en el cerebro y debilitan los mecanismos de defensa de éste (es decir, la barrera sangre/cerebro). Una vez en el cerebro, estos glóbulos activan otros elementos del sistema inmunitario, de forma tal que atacan y destruyen la mielina. También hay pruebas de que la EM es más frecuente entre personas que tienen una susceptibilidad genética. Estas teorías son en realidad complementarias. Un virus común puede activar el sistema inmunitario del cuerpo, haciendo que ataque y destruya mielina del sistema nervioso central en una persona...
(via buenastareas.com)
Multiple sclerosis
Multiple sclerosis (abbreviated MS, also known as disseminated sclerosis or encephalomyelitis disseminata) is an inflammatory condition[1] in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms.[2] Disease onset usually occurs in young adults, and it is more common in women.[2] It has a prevalence that ranges between 2 and 150 per 100,000.[3] MS was first described in 1868 by Jean-Martin Charcot.[4]MS affects the ability of nerve cells in the brain and spinal cord to communicate with each other. Nerve cells communicate by sending electrical signals called action potentials down long fibers called axons, which are wrapped in an insulating substance called myelin. In MS, the body's own immune system attacks and damages the myelin. When myelin is lost, the axons can no longer effectively conduct signals.[5] The name multiple sclerosis refers to scars (scleroses—better known as plaques or lesions) particularly in the white matter of the brain and spinal cord, which is mainly composed of myelin.[4] Although much is known about the mechanisms involved in the disease process, the cause remains unknown. Theories include genetics or infections. Different environmental risk factors have also been found.[5][6]Almost any neurological symptom can appear with the disease, and often progresses to physical and cognitive disability.[5] MS takes several forms, with new symptoms occurring either in discrete attacks (relapsing forms) or slowly accumulating over time (progressive forms).[7] Between attacks, symptoms may go away completely, but permanent neurological problems often occur, especially as the disease advances.[7]There is no known cure for multiple sclerosis. Treatments attempt to return function after an attack, prevent new attacks, and prevent disability.[5] MS medications can have adverse effects or be poorly tolerated, and many patients pursue alternative treatments, despite the lack of supporting scientific study. The prognosis is difficult to predict; it depends on the subtype of the disease, the individual patient's disease characteristics, the initial symptoms and the degree of disability the person experiences as time advances.[8] Life expectancy of patients is 5 to 10 years lower than that of the unaffected population.[2]
(via Wikipedia)