Amyotrophic lateral sclerosis (ALS) is a progressive deterioration of brain and spinal cord nerve cells that control voluntary muscles. The condition is a combination of upper and lower motor neuron deficit. The condition is also referred to as ALS or Lou Gehrig's disease.

The cause of the condition is unknown. A familial form of the condition has been described with inheritance via a dominant chromosome.

The condition is characterized by muscular weakness, and muscular atrophy. There is evidence of anterior horn (front portion of spinal cord) cell dysfunction, affecting the hands and less often the feet. The site of onset is random and progression is often asymmetric. Manifestations may include: fasciculation; spasticity; and overactive deep tendon reflexes; and plantar reflexes. There is eventually dysarthria, and dysphagia.

Tests may include electromyography (EMG) and biopsy of diminished tissue as well as magnetic resonance imaging (MRI) of the brain and/or spinal cord to exclude alternative diseases.

No specific treatment is known. Some medications may slow the progression of the condition. Muscle relaxants may be used to reduce spasticity. An anticholinergic may be used to decrease saliva production. Treatment may also include physical therapy to help maintain muscle function. Orthopedic devices such as braces or a walker may be used to improve mobility.

Residuals may include progressive weakness of the muscles of the extremities and head and neck. A tracheostomy, and nasogastric tube feedings may be needed. The mortality rate with this condition is extremely high. 50% die within 3 years of onset, 20% live for 5 years, and 10% live for 10 years. Once signs or symptoms appear, they do not resolve and are considered permanent.

• This disease shall be granted service connection although not otherwise established as incurred in or aggravated by service if manifested to a compensable degree within the applicable time limits under 38 CFR 3.307 following service in a period of war or following peacetime service on or after January 1, 1947, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied [38 CFR 3.309 [Disease subject to presumptive service connection], 38 CFR 3.309(a) [chronic disease].

• Review 38 CFR 3.318 for consideration of presumptive service connection for amyotrophic lateral sclerosis.

• Consider the need for special monthly compensation.

• It is required for the minimum ratings for residuals under diagnostic codes 8000-8025, that there be ascertainable residuals. Determinations as to the presence of residuals not capable of objective verification, i.e., headaches, dizziness, fatigability, must be approached on the basis of the diagnosis recorded; subjective residuals will be accepted when consistent with the disease and not more likely attributable to other disease or no disease. It is of exceptional importance that when ratings in excess of the prescribed minimum ratings are assigned, the diagnostic codes utilized as bases of evaluation be cited, in addition to the codes identifying the diagnoses.

• Disability in this field is ordinarily to be rated in proportion to the impairment of motor, sensory or mental function. Consider especially psychotic manifestations, complete or partial loss of use of one or more extremities, speech disturbances, impairment of vision, disturbances of gait, tremors, visceral manifestations, injury to the skull, etc. In rating disability from the conditions in the preceding sentence refer to the appropriate schedule. In rating peripheral nerve injuries and their residuals, attention should be given to the site and character of the injury, the relative impairment in motor function, trophic changes, or sensory disturbances.  38 CFR 4.120

• With the exceptions noted, disability from the following diseases and their residuals may be rated from 10 percent to 100 percent in proportion to the impairment of motor, sensory, or mental function. Consider especially psychotic manifestations, complete or partial loss of use of one or more extremities, speech disturbances, impairment of vision, disturbances of gait, tremors, visceral manifestations, etc., referring to the appropriate bodily system of the schedule. With partial loss of use of one or more extremities from neurological lesions, rate by comparison with the mild, moderate, severe, or complete paralysis of peripheral nerves” 38 CFR 4.124a