One study examined 190 people who met the MND/ALS diagnostic criteria, complemented with laboratory research in compliance with both research protocols and regular monitoring. Thirty of these people (16%) had their diagnosis completely changed during the clinical observation development period. In the same study, three people had a false negative diagnosis of MG, which can mimic ALS and other neurological disorders, leading to a delay in diagnosis and treatment. MG is eminently treatable; ALS is not. Management
There is no cure for ALS. Management focuses on treating symptoms and providing supportive care, with the goal of improving quality of life and prolonging survival. This care is best provided by multidisciplinary teams of healthcare professionals; attending a multidisciplinary ALS clinic is associated with longer survival, fewer hospitalizations, and improved quality of life. Riluzole prolongs survival by about 2–3 months. Edaravone slows functional decline slightly in a small number of people with ALS; it is expensive and must be administered by daily IV infusions that may decrease quality of life. Other medications may be used to manage other symptoms.Non-invasive ventilation (NIV) is the main treatment for respiratory failure in ALS. In people with normal bulbar function, it prolongs survival by about seven months and improves quality of life. One study found that NIV is ineffective for people with poor bulbar function while another suggested that it may provide a modest survival benefit. Many people with ALS have difficulty tolerating NIV. Invasive ventilation is an option for people with advanced ALS when NIV is not enough to manage their symptoms.
Higher estimates use a broader definition of familial ALS and examine the family history of people with ALS more thoroughly.In sporadic ALS, there is no family history of the disease. Sporadic ALS and familial ALS appear identical clinically and pathologically and are similar genetically; about 10% of people with sporadic ALS have mutations in genes that are known to cause familial ALS. In light of these parallels, the term "sporadic ALS" has been criticized as misleading because it implies that cases of sporadic ALS are only caused by environmental factors; the term "isolated ALS" has been suggested as a more accurate alternative.More than 20 genes have been associated with familial ALS, of which four account for the majority of familial cases: C9orf72 (40%), SOD1 (20%), FUS (1–5%), and TARDBP (1–5%). 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.ALS and frontotemporal dementia (FTD) are now considered to be part of a common disease spectrum (FTD–ALS) because of genetic, clinical, and pathological similarities. Genetically, C9orf72 repeat expansions account for about 40% of familial ALS and 25% of familial FTD.