lunes, 18 de febrero de 2013

           


                                       
   Lateral Sclerosis Amiatrofica (ALS)


           the disease usually develop around the age of 60 and is less frequently before age 40. It has a course generally slow but this depends on the area of the nervous system which starts the degenerative disease.At the beginning of the disease are frequent muscle cramps, mainly at night, in which muscles tend to shrink spontaneously . The most outstanding feature is the progressive weakness in a person who has muscular atrophy with hyperreflexia (exaggeration of reflexes), fasciculations (fine movements or muscular tension of a small area of muscle) and muscle cramps and sensitivity (absence of sensory symptoms) is not altered.The symptoms are variable in each affected person. It usually starts with
•sensacion of general tiredness.
•Pequenos tremor muscularesbajo skin (fasciculations); cramps.
 •Torpeza in any extremity. •Hiperreflexia (exaggeration of reflexes). Evolucionlas hands and feet are the body parts that previously usually affect, because of the muscle weakness which appear: •Dificultades walking.
 •Dificultades in other activities of daily living: bathing, dressing, etc.
 •the paralysis can spread to the muscles of the neck and trunk. Swallowing problems (dysphagia). Problems chewing. Problems breathing. When the nerves that control the muscles of speech are affected (phonatory) produces a voice of nasal type that sometimes is the first symptom of the disease.Spasticity generalized causing laughter and inappropriate crying, that are part of the disease and not a mental impairment can have.Amyotrophic Lateral Sclerosis only attacks the motor cells, so the senses are not affected:
 •do not there is alteration of the sight, smell, taste and touch.
•Do not there is alteration of the sphincter of the bladder or rectum.
 •Do not there is alteration of the muscles of the eyes. Intact
 •Permanecen automatic muscle functions as the heart and intestines.
 •The sexual function is not affected.
 •The illness by itself does not cause pain.
 • Some which take into account that mental functions are not altered. Three clinical forms are distinguished:
 •comun: usually starts asymmetrically by upper limb.
 •Pseudopolineuritica: it starts by the lower extremities also asymmetrically and it progresses upward slowly.
•Bulbar: evolution faster and almost from the beginning there are dysphasia (difficulty speaking), dysphagia (difficulty swallowing), excessive salivation and increase of mucus. A type of neurons that are called motor neurons or motor neuron are in our nervous system. They go from the brain to the spinal cord (Central motoneurons) and from the cord to the muscles (peripheral motor neuron).   Its function is the transmit signals and orders from the brain to the muscles. To be able to move the hand, the brain sends electrical signals through neurons, which are the vehicles of transmission of messages, the muscles will receive them and is to move the hand. When this transmission is interrupted for any reason, the muscle does not respond, and without this stimulation they atrophy (the term atrophy refers to a decrease in the volume and weight of a body that leads to their lack of functionality).

The Amiatrofica Lateral Sclerosis (ALS) is a degenerative disease (degeneration of nerve cells) of unknown origin that affects both the first motor neuron and the second that causes progressive muscle weakness and resulting in paralysis.Three types of ALS are known:
 •esporadica: is the most frequent form, representing approximately 90% of cases. The disease occurs randomly (by chance), without any known cause and there are other members of the affected family. •Familiar: disease seems to have a hereditary component.
 •Territorial or Guamanian: by observed a frequency of disease (incidence) extremely high in Guam (Pacific). CausasLa cause of the disease is unknown, but various mechanisms or factors that can produce it; being considered Anyway, the source may not be unique, but a combination of several factors.
The main ones are: genetic mechanisms: 10% of ALS cases are inherited source: familial ALS. In this case the inheritance is autosomal (not sex linked) dominant, so if a father has als children have a 50% of inheriting the gene, but not all people with the defective gene will develop the disease.20% Of patients with familial ALS have mutations in a (21q 22.1-22.2) chromosome that encodes an enzyme which is called super oxide dismutase (SOD-1) CU-Zn. Any research on genes or substances involved in the development of the disease can be used for the development of new treatment alternatives. 
    Alterations in the MetabolismoHay an essential amino acid which is essential for the transmission of the nervous impulse, which is glutamate, which in excessive amounts may cause damage to the motor neuron. A high level of glutamate causes an excessive entry of calcium inside the cell, disrupting many cellular functions. There is an alteration in the metabolism of glutamate in ALS. Factors AmbientalesDebido to the high incidence of the disease on the island of Guam, in the Pacific, study the food behavior of the population and other circumstances.
Individuals living in this region had a deficiency State in calcium and high levels of aluminium. In animal models has caused this situation and there was a very similar to ALS syndrome.With medicinal and dietary changes in this population, the frequency of the disease (incidence) was reduced to normal levels in other areas. Although so far no evidence found to link environmental factors with sporadic ALS, epidemiological studies indicate that it is a factor to take into consideration.
 Radical Libres Todas cells release metabolites toxic in the form of radical free, what a way to destroy oxygen that also can be used by the cell, under normal circumstances, to fight the disease. However, an overproduction of radical free may result in damage and cell death. It has been postulated that mutations in the gene Sod - 1 can cause excessive production of radical free and the destruction of the neuron. Inmunologicahasta hypothesis when there is very little evidence of the influence of the immune system in disease; However, the nervous system has its own capacity to provoke an immune response to the injury of neurons. The answer can be restorative to eliminating damaged cells or induce additional damage.There are groups of researchers who consider that in ALS, as well as in other degenerative diseases of the nervous as Parkinson's or Alzheimer's, there is an important local immune responde.

      Deficiency of Factor Neurotroficoson important factors for the growth and maintenance of the motor cells in humans and has been seen in rodents that it increased the survival of these cells. Several attempts have been made to determine if the Neurotrophic factors may slow the rate of progression of the disease. The first clinical trials with different factors Neurotrophic (CNTF, BDNF) did not show any alteration in the evolution of the Commonwealth, but it may be because these factors could not reach the damaged motoneurons. Alteration of the metabolism of the NeurofilamentosLos neurofilaments are the proteins responsible for maintaining the structure of the neuron, so that a change in your metabolism could lead to disease.

The disease occurs in all races and at the level of sex, occurs more frequently in men, but the difference is not very significant.With regard to the most important statistical data include:
 •the 50% of patients die within 18 months of diagnosis.
 •The 80% die within 5 years of diagnosis.
•10% live more than 10 years.
 •It gives more in men (three men for every two women). The sixties, the proportion
 •Pasados man woman is the same.
 •The average home age is 55 years.
•The 80% of the cases start between the ages of 40 to 70 years.
 •The cases diagnosed between 20 and 40 years have a higher chance of survive more than 5 years.