Top 5 ALS Facts
Amyotrophic lateral sclerosis
While the peak age of onset is 58 to 63 for sporadic ALS and 47 to 52 for familial ALS, about 10% of all cases of ALS begin before age 45, and about 1% of all cases begin before age 25. Juvenile ALS is more likely to be familial than adult-onset ALS; genes known to be associated with juvenile ALS include ALS2, SETX, SPG11, FUS, and SIGMAR1. There is no consensus among neurologists on the exact definition of familial ALS. The strictest definition is that a person with ALS must have two or more first-degree relatives who also have ALS. A less strict definition is that a person with ALS must have at least one first-degree or second-degree relative who also has ALS.
Familial ALS is usually said to account for 10% of all cases of ALS, though estimates range from 5% to 20%. Higher estimates use a broader definition of familial ALS and examine the family history of people with ALS more thoroughly. More than 20 genes have been associated with familial ALS, of which four account for the majority of familial cases: C9orf72, SOD1, FUS, and TARDBP. The genetics of familial ALS are better understood than the genetics of sporadic ALS; as of 2016, the known ALS genes explained about 70% of familial ALS and about 15% of sporadic ALS. Overall, first-degree relatives of an individual with ALS have a 1% risk of developing ALS.
ALS has an oligogenic mode of inheritance, meaning that mutations in two or more genes are required to cause disease. Genetically, C9orf72 repeat expansions account for about 40% of familial ALS and 25% of familial FTD. Clinically, 50% of people with ALS have some cognitive and/or behavioral impairments and 5-15% have FTD, while 40% of people with FTD have some motor neuron symptoms and 12.5% have ALS. Pathologically, abnormal aggregations of TDP-43 protein are seen in up to 97% of ALS patients and up to 50% of FTD patients. A 2005 systematic review found no relationship between the amount of physical activity and the risk of developing ALS, but did find that increased leisure time physical activity was strongly associated with an earlier age of onset of ALS.
A 2007 review concluded that physical activity was probably not a risk factor for ALS. A 2009 review found that the evidence for physical activity as a risk factor for ALS was limited, conflicting, and of insufficient quality to come to a firm conclusion. A 2014 review concluded that physical activity in general is not a risk factor for ALS, that American football and soccer are possibly associated with ALS, and that there was not enough evidence to say whether or not physically demanding occupations are associated with ALS. A 2016 review found the evidence inconclusive and noted that differences in study design make it difficult to compare studies, as they do not use the same measures of physical activity or the same diagnostic criteria for ALS. . Smoking is possibly associated with ALS.
A 2009 review concluded that smoking was an established risk factor for ALS. A 2010 systematic review and meta-analysis concluded that there was not a strong association between smoking and ALS, but that smoking might be associated with a higher risk of ALS in women. Among smokers, the younger they started smoking, the more likely they were to get ALS; however, neither the number of years smoked nor the number of cigarettes smoked per day affected their risk of developing ALS. The defining feature of ALS is the death of both upper motor neurons and lower motor neurons. The gross pathology of ALS, which are features of the disease that can be seen with the naked eye, include skeletal muscle atrophy, motor cortex atrophy, sclerosis of the corticospinal and corticobulbar tracts, thinning of the hypoglossal nerves, and thinning of the anterior roots of the spinal cord.
The contestants then donate at least US$10 to ALS research at the ALS Association, the ALS Therapy Development Institute, ALS Society of Canada or Motor Neurone Disease Association in the UK. Any contestants who refuse to have the ice and water dumped on them are expected to donate at least US$100 to ALS research. Additional names for flail leg syndrome that involves both lower legs include pseudopolyneuritic ALS, Patrikios syndrome, Marie-Patrikios ALS, and the peroneal form of ALS..
Amyotrophic Lateral Sclerosis?
ALS is the most common progressive neurodegenerative disease. It is predicted that over 300,000 individuals in the current population of the United States will die due to ALS. It has an incidence of 1-3/100,000 individuals and a prevalence of 3-5/100,000 individuals. ALS is rapidly progressive, having a median survival of only 3-5 years, highlighting the need for advances in treatments. The average onset of ALS occurs between 55-75 years of age for sporadic cases and 45-50 years of age for familial cases.
Most cases of ALS are sporadic, with only 10% of cases being familial. ALS leads to death of both upper and lower motor neurons, leading to progressive loss of neurologic function. As patients experience degeneration of the corticobulbar projections innervating the brainstem, they may develop dysarthria. Patients with ALS typically demonstrate intact sphincter tone and well as bowel and bladder continence. The respiratory muscles are typically involved late in the disease process, with respiratory failure being the leading cause of death in patients with ALS.
ALS is diagnosed by clinical findings and data obtained from electrophysiology testing. The diagnosis of ALS requires signs of both upper and lower motor neuron degeneration. Riluzole is a glutamate inhibitor that may slow the progression of ALS. Edaravone is a free radical and peroxynitrite scavenger approved by the FDA that may help reduce the disability associated with ALS, but impacts on survival were not included as an end-point by the studies performed. A select group of patients that demonstrate gammopathy may benefit from plasmapheresis and immunosuppression.