Unit 1.1: Introduction and Classification

ALS, also known as Amyotrophic Lateral Sclerosis, is a neurodegenerative disease that primarily affects the motor neurons in the brain and spinal cord. It is characterized by progressive muscle weakness, paralysis, and eventually respiratory failure. There are several types of ALS, including Primary Lateral Sclerosis, Progressive Muscular Atrophy, and Kennedy's Disease, each with their own unique characteristics and progression. In terms of epidemiology, ALS is relatively rare, affecting approximately 2 in every 100,000 people worldwide. The exact cause of ALS is still unknown, but research suggests that a combination of genetic and environmental factors may play a role in its development. ALS can occur at any age, but it most commonly affects individuals between the ages of 40 and 70. Clinical presentation of ALS can vary widely among individuals, leading to a diverse range of symptoms and progression patterns. Some patients may experience rapid deterioration of motor function, while others may have a more gradual decline. The variability in clinical presentation has led to the recognition of different phenotypes of ALS, each with its own set of symptoms and prognosis. Overall, ALS is a complex and multifaceted disease that continues to present challenges for researchers and clinicians. Advances in genetics and neuroimaging technologies have improved our understanding of the disease, but much work remains to be done in order to develop effective treatments and therapies for ALS patients.