This will largely be due to the aging of the worlds population, especially in developing countries. History
Descriptions of the disease date back to at least 1824 by Charles Bell. In 1850, François-Amilcar Aran was the first to describe a disorder he named "progressive muscular atrophy", a form of ALS in which only the lower motor neurons are affected. In 1869, the connection between the symptoms and the underlying neurological problems were first described by Jean-Martin Charcot, who initially introduced the term amyotrophic lateral sclerosis in his 1874 paper. Flail arm syndrome, a regional variant of ALS, was first described by Alfred Vulpian in 1886. Flail leg syndrome, another regional variant of ALS, was first described by Pierre Marie and his student Patrikios in 1918.In 1945, American naval doctors reported that ALS was 100 times more prevalent among the Chamorro people of Guam than in the rest of the world. In 1956 the variant of ALS endemic to Guam was named "amyotrophic lateral sclerosis/parkinsonism dementia complex" (ALS/PDC), as it had the typical symptoms of ALS accompanied by parkinsonism-like symptoms; the name in the local language is lytico-bodig disease. Despite a number of genetic and environmental studies, the cause of ALS/PDC remains unknown. Rates peaked in the early 1950s and steadily declined thereafter, and by 1985 the incidence of ALS/PDC in Guam was about the same as the rest of the world.The first gene to be associated with ALS was SOD1, which was identified in 1993.
The El Escorial criteria were designed to standardize patient groups for clinical trials but are not as useful in clinical practice; possible ALS as described by the El Escorial criteria is almost always clinically ALS. Differential diagnosis
Because symptoms of ALS can be similar to those of a wide variety of other, more treatable diseases or disorders, appropriate tests must be conducted to exclude the possibility of other conditions. One of these tests is electromyography (EMG), a special recording technique that detects electrical activity in muscles. Certain EMG findings can support the diagnosis of ALS. Another common test measures nerve conduction velocity (NCV). Specific abnormalities in the NCV results may suggest, for example, that the person has a form of peripheral neuropathy (damage to peripheral nerves) or myopathy (muscle disease) rather than ALS. While a magnetic resonance imaging (MRI) is often normal in people with early stage ALS, it can reveal evidence of other problems that may be causing the symptoms, such as a spinal cord tumor, multiple sclerosis, a herniated disc in the neck, syringomyelia, or cervical spondylosis.Based on the persons symptoms and findings from the examination and from these tests, the physician may order tests on blood and urine samples to eliminate the possibility of other diseases, as well as routine laboratory tests.