Health

Amytrophic Lateral Sclerosis (ALS) is a disorder predominantly characterized by progressive loss of a particular kind of nerve cells (called motor neurons) in the brain and spinal cord (central nervous system or CNS) responsible for the control of muscles that are under conscious control (voluntary or skeletal muscle). Loss of motor neurons may be also be accompanied by progressive degeneration of non-motor neurons that reside in the surface layer (cortex) in portions of the brain known as the frontal and temporal lobes. These cells are responsible for some aspects of thinking and behavior.

Synonyms for Lou Gehrig’s Disease, Motor Neuron Disease (MND) or ALS-MND, Anterior Horn Cell Disease, ALS with Frontotemporal Lobar Degeneration (ALS-FTLD), ALS with Frontotemporal Dementia (ALS-FTD), Progressive Bulbar Palsy (PBP), Primary Lateral Sclerosis (PLS), Progressive Muscular Atrophy (PMA), ALS-PLUS

Overview
ALS results in progressive weakness of voluntary muscles in any of the four body segments: Cranial (head and neck), cervical (neck, arms, hands, and respiratory muscles), thoracic (trunk), lumbosacral (thighs, calves, and feet). It is a life-threatening disorder that produces weakness of breathing and swallowing. The loss of frontotemporal cortical neurons that may accompany loss of motor neurons results in a progressive disorder characterized by a change in personality and or difficulty using or understanding language.

Epidemiology

ALS is a rare disorder with a yearly incidence (new cases in the population) of about 2 to 3 per 100,000 people. Peak incidence occurs in those aged between 40-60 years old. But it can occur in teens as well as those in their 60s. Before 65 years of age, male incidence is twice that of females. However, after 65 years, the incidence becomes equal.

ALS is a uniformly lethal disorder. The causes of death are usually respiratory failure and/or malnutrition and dehydration. The average life expectancy is 3-4 years after diagnosis in 50% of patients. In some, it may result in death less than a year from diagnosis. About 10% of ALS patients can live for 10 or more years after diagnosis.

90% is sporadic (not related to a single gene abnormality). 10% is familial (FALS) which is directly attributable to a mutation in a single gene. 20% of FALS is caused by a mutation in the superoxide dysmutase (SOD1) gene.