Amyotrophic lateral sclerosis (ALS), and also referred to as Lou Gehrig's disease, is a serious neurological disease that affects the neurons responsible for voluntary movement. There is currently no cure for ALS, and in most cases, death occurs within three to five years of diagnosis.
Risk Factors
According to the Mayo Clinic, genetics account for five to 10 percent of diagnosed cases. The remainder of cases are considered to be sporadic. Examination of epidemiological data suggests some possible risk factors that include smoking and a history of military deployment to the Persian Gulf.
Disease Processes
The major disease process in ALS is the progressive destruction of motor neurons. Without motor neurons, the brain loses its ability to send messages to the muscles of the body. The specific mechanism by which the disease destroys motor neurons is not completely understood; however, it is believed that the neurons are destroyed by overexposure to glutamate, the neurotransmitter that the motor neurons use to communicate to the muscle fibers.
Symptoms
Early signs of ALS include weakness and clumsiness in the extremities and slurred speech. A common early symptom of ALS is atrophy and twitching of the tongue. Muscle weakness gradually spreads and progresses, resulting eventually in paralysis. Some patients may also experience muscle twitches and spasms. As the motor neurons die, the muscle tissue that they formerly served begins to waste away due to lack of stimulation, leading to muscular atrophy and weight loss. Cognitive abilities are not affected by ALS.
Diagnosis
In its early stages, ALS may resemble other neurological conditions; therefore, the goal of much of the testing is to identify or rule out other conditions. These tests can include electromyography and nerve conduction studies to assess neurological functioning, imaging studies to assess the physical state of the brain and spinal cord, as well as laboratory tests of blood, urine and cerebrospinal fluid. If there is a family history of ALS, genetic testing is conducted.
Diagnosis of ALS is given when it is determined that there is deterioration of motor neurons that progresses locally and also spreads to other body areas, and when there is no evidence of other disease processes that could produce the observed symptoms.
Treatment
There is no cure for ALS, and it is considered to be a terminal illness. Medical interventions are highly individualized and focus on the needs and symptoms of the patient. Physical therapy can help maintain function and improve overall health and mental well being. Items, such as wheelchairs and walkers, can help improve mobility and allow patients to remain independent for as long as possible. Artificial ventilation and feeding tubes may also be employed as patients lose the ability to breathe and swallow on their own. Most medications given to ALS patients do not address ALS directly, rather they focus on controlling symptoms and helping patients maintain quality of life. There is, however, one drug, called Rilutek, that is approved for use in patients diagnosed with ALS. Rilutek is thought to reduce the harmful effects associated with overexposure to glutamate. Use of the drug has been shown to preserve patients' ability to breathe independently, and increases survival time for an average of two to three months. Emotional support is particularly important for patients diagnosed with ALS, as they retain their full cognitive faculties even as they become progressively more disabled.
