Variation of ALS occurrence between populations and physical activity as a risk factor". Best hardcore anal porn in India. A Systematic Review and Meta-Analysis". In other projects Wikimedia Commons. Flail arm syndrome and flail leg syndrome are often considered to be regional variants of PMA because they only involve lower motor neurons. ALS can be classified as familial or sporadic, depending on whether or not there is a family history of the disease. Journal of the Neurological Sciences.
Disease progression tends to be slower in people who are younger than 40 at onset,  are mildly obese,  have symptoms restricted primarily to one limb, and those with primarily upper motor neuron symptoms.