Amyotrophic Lateral Sclerosis (ALS)
a.k.a. Lou Gehrig's disease
February 18, 2009
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative condition that affects the brain's ability to initiate and control muscle movements. The Greek derivation of the name describes the disease's resulting effects on a person's muscles. In Greek, "A" means no, "myo" refers to muscle, and "trophic" means nourishment, so the literal translation of "amyotrophic" is no muscle nourishment. "Lateral" describes the location of the motor neurons in the spinal cord, where "sclerosis" is the scarring and hardening of the degenerated nerves. It is also called Lou Gehrig's disease because of the prominent New York Yankees player who was diagnosed with the disease.
Because motor neurons are affected, the most common symptom is muscle weakness. Initially, focal weakness is seen affecting muscles in the legs, arms, or even bulbar region which controls swallowing. Symptoms exhibited with lower-extremity motor neuron degradation include muscle weakness, muscle atrophy, fasciculations (muscle twitches), hyperreflexia, hypotonicity, and muscle cramps. Those symptoms associated with upper-extremity motor neurons consist of spasticity, hyperreflexia, and pathological reflexes. Signs of bulbar motor neurons being affected include dysarthria, dysphagia (difficulty swallowing), sialorrhea (drooling), and pseudobulbar palsy.
Two researchers, Sinaki and Mulder, describe the natural course of ALS as six stages:
- -Stage I: Early stage of the disease. Independent in mobility and ADL. A specific group of muscles are mildly weak; may be limitations in performance, endurance, or both.
- -Stage II: Moderate weakness in groups of muscles.
- -Stage III: Still ambulatory but has severe weakness in certain muscle groups. May exhibit mild to moderate limitation of function. May have difficulty holding head erect.
- -Stage IV: Severe weakness of the legs and mild involvement of the arms. May use a wheelchair and may be unable to perform ADL.
- -Stage V: Progressive weakness and deterioration of mobility and endurance. Uses a wheelchair. Arm muscles may exhibit moderate or severe weakness. May exhibit pain in immobilized joints.
- -Stage VI: Bedridden and requires maximal assistance with ADL. Progressive respiratory distress develops.
Because this disease attacks only motor neurons for voluntary muscle, the muscles of the heart and digestive tract are not affected. Therefore cognition, extra-ocular eye movements, and autonomic, bowel, bladder, and sexual functions usually remain intact. However, because breathing can be a voluntary action, ALS can cause difficulty breathing.
Studies have been done analyzing the effects of exercise on people with ALS. One study concluded that people with ALS have abnormal physiologic and metabolic responses including decreased work capacity, but does not prevent the ability to take part in prolonged exercise. Certain exercise programs can improve work capacity, aerobic capacity, as well as decrease heart rate and blood pressure. These improvements can reduce the strains of daily living with ALS.
Expert in Amyotrophic Lateral Sclerosis? DSES is always looking for volunteers to teach or give presentations!!
Resources and Additional Information
ALS Association; www.alsa.org
National Center on Physical Activity and Disability; www.ncpad.org
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