Amyotrophic lateral sclerosis (ALS) which is also refered to by the public as Lou Gehrig's disease is a neurodegenerative disease that affects the brain and spinal cord. It is a form of motor neuron disease, which is rapidly progressive with degeneration of both upper and lower motor neurons. The implication of this is that there is associated complication leading to progressive weakness of muscle, atrophy and some other major voluntary muscular effects. This is because the attack is majorly on the nerve cells controlling the voluntary muscles.
The neurologic condition has been found to have both sporadic and inherited (familial) forms (Phukan, 2007). It has also been stated that scientist understand more of the genetic etiological perspective of the inherited forms of ALS when compared to sporadic forms because more of environmental factors were implicated in the sporadic form. The important feature of the condition is that the sensory aspect of the brain is usually spared hence there is no affectation of neurosensory function of the patient. This condition has no cure but different researches are ongoing regarding the cure. However, there are different management strategies that focus mainly on symptomatic management of the affected individual.
ALS impaired the transfer of messages from the upper motor neuron (brain) to the lower motor neuron (spinal cord) subsequently affecting the information needed for the voluntary muscle to achieve the functions. The consequences of these events are that progressively the affected individual loses the ability to raise or use their limbs because of the loss of strengths and atrophy of those muscles. It also affects the respiratory muscles such as the diaphragm hence the ability to breath voluntarily with death consequence in most situations.
Several researches have been conducted regarding the ALS. Those researches have focused on different aspect of the condition helping to achieve the etiology, Pathophysiology, signs and symptoms and possible cure for the condition. Nizzardo et al (2011) recently conducted a research on the role of gene therapy in management of ALS. They found adeno-associated virus vectors to be an important gene transfer mechanism, which could help in clinical translation in managing the condition. Their focus was on generating a genetic method of silencing the implicated superoxide dismutase-1, which has been the pathogenic target in ALS (Nizzardo et al, 2011). The research was conducted on animal models and could be applied to humans in the nearest future. The implication of this research is that, we should hope for finding of the cure in the nearest future.
Vaknin et al (2011) in their research found an increase level circulating Alternatively Activated Myeloid cells tend to accelerate the progression of the ALS. This was found to be because of the impairment of the T-cell activity, which those myeloid cells caused when they are in excess in the body hence leading to increased progression of ALS. T-cells are usually needed to help fight the progression but when impaired, their role is affected (Vaknin et al, 2011).
Desiree (2011) in an CME article titled "More evidence links smoking to increased ALS risk", shows from different cohort studies that smoking is related to ALS. It was concluded from the review of those studies that both old and new smokers are associated with higher risk of ALS and there is no gender predilection among smokers to the condition. It was also found that earlier onset of smoking also increased the chances when compared to nonsmokers (Diseree, 2011).
There are different types of nerves in the body. Each are equipped with different features, which makes them perform separate functions. Some perform the functions of thinking, memory, why some are sense detection and some for muscular control. The nerves involve in voluntary muscle control are those that are involved in amyotrophic lateral sclerosis.
Certain pathogenic mechanisms have also been found to contribute to the motor neuron injuries leading to the ALS. These include Genetic factors, oxidative stress, protein aggregation, glutamatergic toxicity, mitochondrial dysfunction, and impairment of axonal transport, inflammatory cascades, and dysfunctional signaling pathways (Shaw, 2005)
The molecular mechanism in the pathogenesis has been described and this shows impaired axonal transport by various factors highlighted above. This then affects neuronal function. Programmed cell death may also contribute to the death of the nerve cells. When muscle lack neuronal impulse from the upper motor neuron, there is consequential loss of strength of the muscle. This is due to atrophy that sets in because of demise of neuronal functions. Once the muscle start undergoing atrophy, there will be a vivid weakness or wasting of the muscle. Other major pathological changes with the loss of neuronal signal to the muscle include fasciculation, muscle cramping, or stiffness.
The upper and lower limbs are usually affected first when the damage sets in. Other muscles such as diaphragm and intercostals muscles then start showing the symptoms of degeneration. The condition also affects other muscles involve in swallowing, or tongue muscles. This is because they are also voluntary muscles. The physiological functioning of those muscles is then affected. These include inability to chew well or swallow, difficulty in breathing, and problems with the movement of the limbs.
The management of patients with the condition is dependent on symptomatic management because of the lack of cure for the muscle degeneration. Most important is that which relates to the supportive care. The health care professional can help reduce the complications of the condition. Provision of respiratory aid is an example of supportive care that can also help in breathing. Physiotherapist and other social health worker can help in managing the physical and cognitive issues associated with the condition. Since the prognosis of the condition is poor, proper symptomatic management is essential to improve the lifestyle of the patients.
The current perception as regards to the disorder is that there is no cure presently. However, there are several ongoing researches involving various aspects of the condition. Different clinical trials at different phases are ongoing to find the cure and the best mode of management. Mitotarget is an ongoing research to understand the mitochondrial dysfunction in neurodegenerative disease and the application of the identified changes in the developing newer therapeutics.
Talampanel is a new drug that is undergoing clinical trial (phase II). The study is being conducted to identify the efficacy, tolerability, and oral administration of the medication in patients with ALS.
It is more than a century since the discovery of the condition by the French neurologist Jean Charcot However, the cure is yet to be found. The condition is the most common of the neurodegenerative disorders affecting the voluntary muscles. Since its progressive, it kills slowly. Although, several studies have been conducted on the condition and some are ongoing, it should be noted that supportive care is the most important symptomatic care that can help prolong the life of the affected individual.
References
ALS Association, (2011). What is ALS?.
Retrieved November, 2011 from http://www.alsa.org/about-als/what-is-als.html
Buehler, B., (2010). Lou Gehrig and Amyotrophic Lateral Sclerosis: A Lesson for Future Generations. Medscape Connect.
Retrieved 21 November, 2011 from http://boards.medscape.com/forums?@.2a0287c7!comment=1
Brooks, M., (2011). Common cause of ALS discovered. Medscape.
Retrieved 21 November, 2011 from http://www.medscape.com/viewarticle/748453
ClinicalTrials.gov, (2011). Talampanel for Amyotrophic Lateral Sclerosis (ALS).
Retrieved November, 2011 from http://clinicaltrials.gov/ct2/show/NCT00696332?term=ALS&rank=2
Desiree, (2011). More evidence links smoking to increased ALS risk. CME. Medscape Education.
Retrieved 21 November, 2011 from http://www.medscape.org/viewarticle/738056
European Commission, (2011). Mitotarget; Mitochondrial dysfunction in neurodegenerative diseases: towards new therapeutics. Research and Innovation-health.
Retrieved November, 2011 from http://ec.europa.eu/research/health/medical research/brain-research/projects/mitotarget_en.html
Phukan et al, (2007). Cognitive impairment in amyotrophic lateral sclerosis. ScienceDirect.
Retrieved November, 2011 from http://www.sciencedirect.com/science/article/pii/S147444220770265X
Shaw, P.J., (2011). Molecular and cellular pathways of neurodegeneration in motor neurone diseas. Neuroscience for neurologists.
Retrieved November, 2011 from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1739758/pdf/v076p01046.pdf
Turner et al, (2011). Cardiovascular fitness as a risk factor for amyotrophic lateral sclerosis: indirect evidence from record linkage study.
Retrieved November, 2011 from http://www.ncbi.nlm.nih.gov/pubmed/22072701
Nizzardo et al, (2011). Research advances in gene therapy approaches for the treatment of amyotrophic lateral sclerosis. PubMed
Retrieved November, 2011 from http://www.ncbi.nlm.nih.gov/pubmed/22094924
Vaknin et al, (2011). Excess Circulating Alternatively Activated Myeloid (M2) Cells Accelerate ALS Progression While Inhibiting Experimental Autoimmune Encephalomyelitis. PubMed.
Retrieved November, 2011 from http://www.ncbi.nlm.nih.gov/pubmed/22073221
