Amyotrophic lateral sclerosis (ALS) is more commonly known as Lou Gehrig's disease. The disease is progressive, disabling and fatal. It involves a wasting of certain brain and spinal-column nerve cells called motor neurons, which control voluntary muscle movements. The course of the disease is different for everyone and some people live with ALS for several years.
A typical first sign of ALS is slight weakness in one leg, one hand, the face or tongue. Other potential problems are clumsiness and difficulty performing tasks that require precise movements of the fingers and hands. Frequent muscle twitching may occur.
Over months or years, ALS spreads to the arms and legs, weakening muscles and reducing control of movement. Problems emerge with walking, speaking, eating, swallowing and breathing. Many symptoms of ALS become more difficult with time and can themselves create additional complications, illnesses or injuries.
Although nerves and muscle cells continue to increasingly lose viability, a patient’s memory and ability to think and reason usually are not affected by ALS.
The cause of ALS is unknown. The condition is not contagious, though approximately 10 percent of people with ALS have an inherited form of the disease.
In the United States and most other parts of the world, one to two people out of 100,000 develop ALS each year. Men are affected slightly more often than women. Although ALS may occur at any age, it most commonly occurs in middle-aged and older adult.
ALS can be difficult to diagnose, and may not be defined until symptoms have progressed or without additional testing and observation. Diagnosis is usually made by a neurologist who specializes in neurological issues.
Diagnosis involves a thorough evaluation of a patient’s medical history and detailed physical/neurological exam. The patient’s nerve and muscle function are measured to confirm a diagnosis. Such tests may include:
- Electromyogram (EMG) to measure the electrical potential in muscle cells, both while active and at rest
- Nerve-conduction studies, in which nerves are stimulated and monitored for how well they convey these signals
Additional tests can help rule out other potential causes of symptoms:
- Nerve or muscle biopsy (tissue sample)
- Blood tests
- Computed tomography (CT) imaging scans
- Magnetic resonance imaging (MRI) scans
As the muscles that control swallowing become weaker, some people have problems with food and saliva being inhaled into the windpipe. Taking medication and getting enough food can also become difficult and may require a tube to be surgically inserted into the stomach (percutaneous endoscopic gastrostomy, or PEG) to carry nourishment.
As the muscles of the chest become weaker, patients require extra oxygen through a BiPap (bi-level positive airway pressure) or NPPV (noninvasive positive pressure ventilation) machine. As breathing problems become more acute, a tracheotomy (surgical opening in the neck leading to the windpipe) and ventilator, or breathing machine, may be considered. Most patients, however, find the burden of using a ventilator difficult or impossible to manage at home, and will choose NPPV instead.