The Amyotrophic Lateral Sclerosis (ALS) or" Lou Gehrig's Disease "Is a neurological disease of the degenerative type with a progressive cuso that affects the Motor neurons Which are located in the brain and spinal cord (The Journal American Medical Association, 2007).
The degeneration of this type of neurons that are in charge of transmitting the orders of the voluntary movements to the muscles, makes that the capacity of the Brain to start motor execution is lost. Therefore, patients begin to show progressive muscular atrophy and develop A severe paralysis (Miquel Valls Foundation, 2016).
In addition to motor impairment, impaired ability to articulate language, swallowing or breathing, recent studies have shown that This type of disease can also appear associated with dementia fronto-temporal processes, showing cognitive and behavioral alterations in the Individuals (Fundación Miquel Valls, 2016).
It is a disease with a progressive course, invariably fatal (National Institute of Neurological Disorders and Stroke, 2013). Despite this, quality of life Of patients, and even survival time, may vary significantly depending on the type of medical performance (Orient-López et al., 2006).
Prevalence of amyotrophic lateral sclerosis
In many cases, amyotrophic lateral sclerosis is considered a rare or minor type disease. The number of people suffering from this Disease is between 6 and 8 people per 100,000 inhabitants. Despite this, we must take into account that the incidence of the disease is 1-3 cases New per 100,000 inhabitants each year (Fundación Miquel Valls, 2016).
The statistical estimates put the number of cases of amyotrophic lateral sclerosis in Spain in approximately 4,000, while at the global level Is estimated at about 350,000 cases (Fundación Miquel Valls, 2016).
ALS is more prevalent in men than in women, approximately 1.2-1.6: 1, and is usually present in individuals with adulthood. HE Estimates that the mean age at onset is about 56 years of age and that presentation is scarce before age 40 or after age 70 (Orient- López et al., 2006). However, there are cases of the disease in people 20-40 years old (Amyotrophic Lateral Sclerosis Association, 2016)
On the other hand, the average duration of the disease is usually three years, reaching a survival of more than 5 years in 20% of those affected and more than 10 years in 10% of these patients (Orient-López et al., 2006).
Generally more than 90% of cases of ALS occur randomly without presenting a clearly defined risk factor. Patients usually do not Have an inherited history of the disease, or are not considered to be at high risk for developing ALS. Alone 5-10% of cases of ALS are inherited (National Institute of Neurological Disorders and Stroke, 2013).
Definition of Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis is a neuromuscular disease that was discovered in 1874 by Jean-Martin Charcot . He described her as a type Of disease in which nerve cells control the movement of voluntary muscles, Motor neurons , Decrease their efficient operation Progressively and die, leading to weakness followed by severe motor atrophy (Paz Rodríguez et al., 2005).
Motor neurons are a type of nerve cell that can be located in the brain , he Brain stem and the spinal cord . These motor neurons Serve as centers or units of control and information flow link between the voluntary body muscles and the nervous system (National Institute of Neurological Disorders and Stroke, v).
Information from motor neurons located at the brain level (called upper motor neurons) are transmitted in turn to the Motor neurons that are located at the level of the spinal cord (denominated inferior motor neurons) and from there, the flow of information is sent to each (National Institute of Neurological Disorders and Stroke, 2013).
Thus, in amyotrophic lateral sclerosis, degeneration or death will occur in both upper motor neurons and motor neurons National Institute of Neurological Disorders and Stroke, 2002) and will therefore prevent the essential chemical and nutrient messages that Require the muscles for proper functioning do not reach the muscle areas (Paz-Rodríguez et al., 2005).
Due to inability to function, muscles will progressively show weakness, atrophy, or contractions (fasciculations) (National Institute of Neurological Disorders and Stroke, 2013).
Specifically, in this pathology there is a specific definition of each of its terms (Paz-Rodríguez et al., 2005):
- Sclerosis: means"hardening". Specifically, it means hardening of tissue when disintegration occurs.
Nerve pathways (Paz-Rodríguez et al., 2005). - Lateral: implies the notion of"side", and refers to the nerves that run bilaetral in the spinal cord (Paz-Rodríguez et al., 2005).
- Amyotrophic: this term is usually used as"related to muscular atrophy", it is a severe degeneration of motor neurons that
Will lead to progressive paralysis of the muscles involved in movement, speech, swallowing, or breathing (Paz-Rodríguez et al.
2005).
Symptoms of Amyotrophic Lateral Sclerosis
In many instances, the onset can be very subtle showing signs so mild that they are often overlooked (National Institute of Neurological Disorders and Stroke, 2013).
Early symptoms may include contractions, cramps, muscle stiffness, weakness, impaired speech, difficulty chewing (National Institute Of Neurological Disorders and Stroke, 2013). Specifically, they may appear (Amyotrophic Lateral Sclerosis Association, 2016):
- Muscular weakness In one or more of the following areas: upper limbs (arms or hands); Lower limbs (specifically legs); from The articulatory muscles of language; Muscles involved in swallowing or breathing.
- Tics or muscle cramps , Which occur more commonly in the hands and feet.
- Inability to use arms or legs .
- Deficits in language : Like"swallowing the words"or difficulty of projection of the voice.
- In more advanced stages: shortness of breath, difficulty in breathing or swallowing.
The parts of the body that will be affected by the first symptoms of lateral sclerosis amyotrophy will depend on which muscles of the body are damaged First (National Institute of Neurological Disorders and Stroke, 2013). So the initial symptoms usually vary greatly from one person to another.
In In some cases you may experience tripping, difficulty walking or running as the main form of manifestation, while others may Difficulties when they need to use a higher limb, problems lifting or picking up objects, or in other cases presenting stuttering (Amyotrophic Lateral Sclerosis Association, 2016).
Progressively, the involvement in a muscle or limb area extends contralateral. Thus, the deficit becomes symmetrical in the Four limbs. In a time no longer than one year, the great part of the patients presents tetraparesia with a degree of major or minor of gravity (Orient-López et al., 2006).
Little by little, the evolution of the disease will affect the bulbar level, causing an alteration of the musculature of the neck, face, pharynx and larynx. A severe alteration of the articulation of words and of the swallowing begins, in its beginning of liquids and progressively also of solids (Orient-López et al., 2006).
In the later stages of the disease when the pathology is in advanced stages, weakness and muscular paralysis extends to the Respiratory muscles (Orient-López et al., 2006), patients lose their ability to breathe autonomously and it will be necessary to use a Respirator to maintain this vital function (National Institute of Neurological Disorders and Stroke, 2013)
In fact, respiratory failure is the most prevalent cause of death in people with amyotrophic lateral sclerosis, while others Causes like pneumonia Are less prevalent (The Journal American Medical Association, 2007).
In most cases, within 3-6 years after the initial presentation of symptoms, the patient's death usually occurs, Although in some cases they usually live several decades with this pathology (The Journal American Medical Association, 2007).
Due to the fact that amyotrophic lateral sclerosis mainly affects motor neurons, somatosenrial, auditory, gustatory and Smell will not be affected. In addition, in many cases there will also be no affectation of ocular mobility and sphincter function (Amyotrophic Lateral Sclerosis Association, 2016).
Causes of Amyotrophic Lateral Sclerosis
The specific causes of amyotrophic lateral sclerosis are not exactly known. In cases in which the disease presents Genetic factors related to three autosomal dominant transmission loci (21q22, 9q34 and 9q21) and two Autosomal recessive transmission (2q33 and 15q15-q21) (Orient-López et al., 2006).
However, a number of causes have also been proposed as potential etiologic factors of amyotrophic lateral sclerosis: environmental, Exposure to heavy metals, viral infections, prion diseases, autoimmune factors, paraneoplastic syndromes, etc., although they do not exist Irrefutable evidence of their role (Orient-López et al., 2006).
Some of the pathophysiological mechanisms that have been identified in relation to this pathology are (Fundación Miquel Valls, 2016):
- Reduced availability of neurotrophic factors
- Disorders of calcium metabolism
- Excitoticity due to excess glutamate
- Increased neuroinflammatory response
- Changes in the cytoskeleton
- Oxidative stress
- Mitochondrial damage
- Protein aggregation
- Transcription alterations
- Other factors.
Because of this initial description that emphasizes the incidence of genetic factors, clinical investigations have proposed several types of sclerosis Amyotrophic lateral sclerosis (Amyotrophic Lateral Sclerosis Association, 2016):
- Sporadic : It is usually the most prevalent form of amyotrophic lateral sclerosis. Specifically, in the United States it is around 90-95% of all cases. However, endogenous (metabolic and genetic) factors and exogenous (environmental, he Individual's lifestyle ) (Miquel Valls Foundation, 2016).
- Family : Usually due to a dominant genetic inheritance and occurs more than once in a family line. It represents a small amount of Cases, around 5-10%. The implication of some genes has been described: SOD1, Alsina, VAPB, TARDBP, FUS, Sechin, OPTN, VCP, ANG, UBQLN2, C9ORF72 (Miquel Valls Foundation, 2016).
- Gumaniana: Different studies have observed a high incidence of amyotrophic lateral sclerosis in Guam and in Territories in Pacific in the 1950s. (Amyotrophic Lateral Sclerosis Association, 2016).
Diagnosis
Amyotrophic lateral sclerosis is a pathology difficult to diagnose. There is currently no single test or procedure to perform The definitive diagnosis of the disease (Amyotrophic Lateral Sclerosis Association, 2016).
Therefore, the diagnosis of this type of pathology is mainly clinical and is based on the demonstration of the presence of signs and symptoms Of motor neuron involvement, such as weakness, atrophy or fasciculation (Orient-López et al., 2006).
A complete differential diagnosis should include most of the procedures listed below (Amyotrophic Lateral Sclerosis Association, 2016):
- Electromyography (EMG) and nerve conduction analysis (NCV).
- Blood and urine tests Must include Electrophoresis Of serum protein, analysis of thyroid and parathyroid hormone levels and detection Of heavy metals.
There are several diseases that can cause some of the symptoms that occur in ALS. Because many of these are treatable, the Amyotrophic Lateral Sclerosis Association (2016), recommends that a person who has been diagnosed with ALS seek a second opinion with a professional To discard possible false positives.
Treatment
Currently, experimental studies have found no cure for ALS. So far no cure has been found for ALS (National Institute of Neurological Disorders and Stroke, 2013)
The only drug that has proven a delay in this pathology is Riluzol (Amyotrophic Lateral Sclerosis Association, 2016). It is thought that this drug Reduces damage to motor neurons by decreasing the release of glutamate (National Institute of Neurological Disorders and Stroke, 2013)
In general, treatments for ALS are aimed at relieving symptoms and improving the quality of life of patients (National Institute of Neurological Disorders and Stroke, 2013).
The most current studies show that comprehensive and multidisciplinary care that integrates medical care, Pharmaceuticals, physical therapies, occupational, speech, nutrition, social, etc., improve the quality of life of patients affected by ALS And their families, contributing to the prog- ress of disease progression (National Institute of Neurological Disorders and Stroke, 2013, Miquel Foundation Valls, 2016).
CONCLUSIONS
The progressive and incapacitating nature of ALS, coupled with the fact that there is no cure, makes it a difficult disease to manage. In addition to Care, patients need emotional support from family, friends, physicians, and caregivers. Patient (The Journal American Medical Association, 2007).
References
- Association, A. M. (2016). Amyotrophic lateral sclerosis, ALS. The Journal of the American Medical Association, 298 (2).
- Catalan Foundation of Amyotrophic Lateral Sclerosis Miquel Valls . (2016). Retrieved from http://www.fundaciomiquelvalls.org/en/
- Orient-López, F., Terré-Boliart, R., Guevara-Espinosa, D., & Bernabeu-Guitart, M. (2006). Neurorehabilitator treatment of lateral sclerosis Amyotrophic. Rev Neurol, 43 (9), 549-555.
- Paz-Rodríguez, F., Andrade-Palos, P., & Llanos-Del Pilar, A. (2005). Emotional consequences of patient care with lateral sclerosis Amyotrophic. Rev Neurol, 40 (8), 459-464.
- Image source.