Amyotrophic lateral sclerosis (ALS)

 

Amyotrophic lateral sclerosis (ALS) belongs to a group of disorders known as motor neuron diseases. Motor neurons are nerve cells located in the brain, brainstem, and spinal cord that serve as control units and communication links between the nervous system and the voluntary muscles of the body. The loss of these cells causes the muscles under their control to weaken and waste away, leading to paralysis. ALS is often fatal within five years of diagnosis, mainly due to respiratory failure. People who opt for permanent use of a feeding tube and a ventilator after the failure of swallowing and respiratory muscles can generally be kept alive for many more years.

ALS symptoms may include frequent tripping and falling; loss of control in hands and arms; difficulty speaking, swallowing, and breathing; persistent fatigue; and twitching and cramping. Typically, ALS strikes in midlife. For reasons unknown, men are about one-and-a-half times more likely to have the disease than women. Because ALS affects motor neurons, the disease does not usually impair a person’s mind, personality, or intelligence. It does not affect the ability to see, smell, taste, hear, or recognize touch. People with ALS usually maintain control of eye muscles and bladder and bowel function.

There is no known cure for ALS, nor is there a therapy to prevent or reverse its course. ALS experts have identified numerous compounds that show promise for treating the disease. Several drugs and cell therapies are currently being tested in patients. There is strong evidence that trophic factors, molecules that nurture and protect cells, can rescue dying neurons in animal models of ALS. Indeed, targeted delivery to a vulnerable cell may be beneficial. So far, human trials have failed to follow up on success in animals. This work is still in progress.