**3. Symptom statistics**

ALS occurs between the ages of 40 years and 70 years, but the disease can occur at a younger age also. It affects throughout the world without any ethnic, racial or socioeconomic bounda‐ ries. ALS is responsible for almost five of every 100,000 deaths in people aged 20 or older. The frequent age for ALS is after 60 years age. The incidence of ALS is five times higher than Huntington's disease and almost equal to multiple sclerosis. Fifty percent of affected patients live at least three or more years after diagnosis, 20 percent live 5 years or more and up to 10 percent will survive more than 10 years (adapted from http://www.hopkinsmedicine.org/ neurology\_neurosurgery/centers\_clinics/als/conditions/als\_amyotrophic\_lateral\_sclero‐ sis.html).
