Initially, dysphagia may be managed by dietary changes and modified swallowing techniques. Difficulty swallowing liquids usually develops first and can be managed by switching to thicker liquids like fruit nectar or smoothies, or by adding fluid thickeners to thin fluids like water and coffee. People with ALS should eat soft, moist foods, which tend to be easier to swallow than dry, crumbly, or chewy foods. They should also be instructed on proper head posture during swallowing, which can make swallowing easier. There is tentative evidence that high-calorie diets may prevent further weight loss and improve survival.A feeding tube should be considered if someone with ALS loses 5% or more of their body weight or if they cannot safely swallow food and water. This can take the form of a gastrostomy tube, in which a tube is placed through the wall of the abdomen into the stomach, or a nasogastric tube, in which a tube is placed through the nose and down the esophagus into the stomach. A gastrostomy tube is more appropriate for long-term use than a nasogastric tube, which is uncomfortable and can cause esophageal ulcers. The feeding tube is usually inserted by percutaneous endoscopic gastrostomy (PEG). There is some evidence that a PEG tube should be inserted before vital capacity drops below 50% of expected, as a low vital capacity may be associated with a higher risk of complications.
Around half of people with ALS die within 30 months of their symptoms beginning, and about 20% of people with ALS live between five and ten years after symptoms begin. Guitarist Jason Becker has lived since 1989 with the disorder, while cosmologist Stephen Hawking lived for 55 more years following his diagnosis, but they are considered unusual cases. Cause
Though the exact cause of ALS is unknown, genetic and environmental factors are thought to be of roughly equal importance. The genetic factors are better understood than the environmental factors; no specific environmental factor has been definitively shown to cause ALS. A liability threshold model for ALS proposes that cellular damage accumulates over time due to genetic factors present at birth and exposure to environmental risks throughout life. Genetics
ALS can be classified as familial or sporadic, depending on whether or not there is a family history of the disease. 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 (children, siblings, or parents) 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 (grandparents, grandchildren, aunts, uncles, nephews, nieces or half-siblings) 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%.