ALS: Amyotrophic Lateral Sclerosis

ALS was first discovered in France, in 1869 by a French neurologist by the name of Jean- Martin Charcot. It didn’t get national attention until Yankee Hall of Famer, Lou Gehrig, contracted this disease, shortening his baseball career. Today ALS is sometimes referred to as Lou Gehrig’s Disease. Surprisingly, much is still unknown about this fatal neuromuscular condition and there still isn’t a cure. Current research is concentrating on understanding the mechanisms of disease progression. Some advances have been made, but much still needs to be discovered.

Mechanism of Action

The National Institute of Neurological Disorders and Stroke (NINDS) estimates that Twenty thousand Americans currently have ALS, with another five thousand diagnosed yearly. ALS is a rapidly destructive and fatal neurological disorder, that affects the nervous system’s ability to communicate with the voluntary muscles of the body. This disease specifically affects the motor neurons. These neurons become less effective under the progression of the disease and eventually stop transmission completely. This loss of transmission causes the voluntary muscles to weaken, affecting voluntary control and strength, followed by speech impairment and eventual respiratory failure. This progression usually occurs within three to five years from the onset of the disease.

Who gets it?

Although one of the more common neuromuscular diseases worldwide, NINDS estimates ninety to ninety-five percent of all people affected have no common associated risk factors. This disease affects all races and genders. Although the majority of people get the disease between the ages of forty and sixty, ALS can affect anyone at any age. The National Institute of Health, states that only five to ten percent of the people who contract this disease, do so from heredity. Some of these people have a mutation in the enzyme super oxide dismutase (SOD1). However, others who have family histories of ALS have normal SOD1 enzyme activity, indicating that there is more than one marker for this disease. Other areas being looked at include exposure to toxic substances, damage from free radicals, antibodies produced by auto-immune responses as well as overexposure to a neurotransmitter chemical Glutamate, that seems to cause healthy neurons to die, when exposed to excessive amounts.

Diagnosis and Treatment

Diagnosis of ALS is difficult. Usually electromyography (the testing of electrical activity within the muscles) and nerve conduction velocity tests can help support a diagnosis of ALS. Most of the time, however, tests must be conducted to rule out a whole range of other diseases that can mimic the symptoms of ALS first. Although no cure has been found, the FDA has approved a drug Ritulek, to help combat overexposure to the chemical messenger, Glutamate. Other treatments are mostly supportive. These include medications to relieve muscular symptoms, such as cramping and physical therapy of various sorts. Mechanical ventilation may be needed for advanced cases.

The National Institute of Neurological Disorders and Stroke is currently researching different mechanisms seen in ALS. They are trying to find out why certain motor neurons degenerate, while others don’t, and a way to halt this process. Study of families with ALS history are being scrutinized, especially those without the SOD1 mutation, to find other causes for ALS and to find a consistent biological marker that can be used for early ALS diagnosis. Animal testing is also being done to see if normal SOD1 and the use of antioxidants can stop neural degeneration. Until a definitive biological marker for genetic risks and subsequent cure can be found, ALS will continue to perplex the medical community.