An estimated 30,000 Americans are affected by amyotrophic lateral sclerosis a neurodegenerative condition that causes the motor neuron cells in the spinal cord to gradually die off, keeping neural impulses from the brain from reaching the muscles. Muscle function slowly diminishes, making movement increasingly difficult. It is also known as Lou Gehrig's disease, after the New York Yankees player who was diagnosed with the condition in 1939, famously leading to his retirement from baseball, and who ultimately dies of the disease two years later. The condition typically begins with weakness in the arms and legs—the first symptom Gehrig noticed—and difficulty in breathing and swallowing. The muscles slowly begin to atrophy and eventually no longer work. In the end, the muscles needed for breathing no longer function.
The cause of ALS is unclear. Researchers believe it may be related to structures in the motor neurons called neurofilaments. In ALS, those neurofilaments are not constructed properly, so they malfunction. The task of the neurofilament is to transport molecules around motor neurons to enable the motor neurons to activate the muscles. The malfunctioning neurofilaments are unable to do this, so the molecules end up stuck, misplaced, or scattered. The researchers say the largest motor neurons, with the longest filaments, are in the legs, which is why the first signs of Lou Gehrig's disease are in the legs and feet.
There is no cure for ALS. Palliative care can make it possible for patients to live, and assistive technology allows them to prolong their independence, but nothing can be done to reverse or even stop the damage. However, there is some indication that an experimental drug for treating stroke patients may also disrupt a key mechanism of Lou Gehrig's disease. In experimental animals, this medication slowed down motor neuron death and delayed the progress of the disease.
Another possible treatment being investigated involves a copper compound that scientists hope will slow the condition and significantly improve the life expectancy of patients. Current treatments can extend lifespan by a handful of months at most. Since some of the damage ALS does has been traced to insufficient copper in the spinal cord, additional copper is thought to help. The compound allows the normally toxic metal to be administered safely; it is hoped this will prevent the damage from occurring, halting the disease.