Symptoms & Causes

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, affects nerve cells in the brain, brain stem, and spinal cord that control voluntary muscle movement. It is a slowly progressive neurodegenerative disease that weakens muscles throughout the body, including those for speech, swallowing, and breathing. Patients may also experience minor emotional, behavioral, or cognitive issues. Most ALS patients have fasciculations (involuntary muscle twitches) and develop skin changes that reduce the risk of bed sores. Sensory functions like eye movements are typically preserved, and pain is generally minimal or absent. ALS usually strikes people in their fifth or sixth decade of life, affecting both men and women. While the cause of most cases is unknown (sporadic ALS), about 5-10% are inherited (familial ALS).

Lou Gehrig, renowned as the "Iron Horse" of baseball, famously battled ALS. After retiring from the New York Yankees in 1939 due to ALS, ending his streak of 2,130 consecutive games, Gehrig relied on his wife, Eleanor, who became his caregiver, chauffeur, and nutritionist. She supported him through daily routines, including administering vitamin E injections and preparing unconventional salads in a desperate attempt to slow the disease progression. Despite their efforts, Lou Gehrig succumbed to ALS in 1941, leaving a lasting legacy intertwined with the history of the Muscular Dystrophy Association.

Symptoms

Symptoms of ALS typically emerge after age 50, though onset can occur earlier. The disease causes progressive muscle weakness and coordination loss, making routine tasks like climbing stairs, standing up, or swallowing increasingly difficult or impossible.

Initially, weakness may affect the arms, legs, or respiratory and swallowing functions. As ALS advances, more muscle groups are affected. Importantly, ALS does not impair sensory abilities or cognitive function in most cases, although a minority may experience dementia symptoms affecting memory.

Muscle weakness typically starts in a specific body part, such as the arms or hands, and worsens over time, leading to:

  • Difficulty with lifting, walking, and climbing stairs
  • Breathing difficulties
  • Swallowing problems, including choking, drooling, or gagging
  • Neck muscle weakness causing head drooping
  • Speech issues like slurred or slow speech
  • Hoarseness or changes in voice

Additional symptoms may include depression, muscle cramps, stiffness (spasticity), involuntary muscle twitches (fasciculations), and weight loss.

Causes

ALS is a disease where one in 10 cases stem from genetic defects, while its cause remains unknown in most others.

In ALS, motor neurons deteriorate, hindering their ability to transmit messages to muscles. This deterioration leads to muscle weakening, twitching, and eventually an inability to move the arms, legs, and body. Over time, the condition progressively worsens, potentially causing difficulty or inability to breathe when chest muscles fail.

Approximately 5 out of every 100,000 people worldwide are affected by ALS.

Having a family member with a hereditary form of ALS increases the risk of developing the disease. Other potential risk factors include military service, possibly due to exposure to environmental toxins, although the exact reasons remain unclear.