Degenerative Spinal Cord Diseases

Degenerative spinal cord diseases affect the nerve cells that oversee peripheral motor and sensory functions. Degenerative spinal cord diseases differ from "degenerative spinal diseases," which refers to conditions of the bones of the spinal column.

Degenerative spinal cord diseases are neurological conditions, such as amyotrophic lateral sclerosis (ALS, or "Lou Gehrig's Disease") and spinal muscular atrophy (SMA). SMA and ALS disease are two progressive motor neuron diseases. This means that they are characterized by the destruction of motor neurons. Motor neurons are nerve cells that control voluntary muscle activities such as:

• Breathing
• Speaking
• Swallowing
• Walking.

Amyotrophic Lateral Sclerosis (ALS)

ALS disease (or Lou Gehrig's disease) attacks neurons in the brain and spinal cord. The neurons no longer can send messages to your voluntary muscles. Muscle problems develop, leading to loss of strength and ability to contract. When the chest muscles fail, most people with ALS disease die from respiratory failure.

Early ALS symptoms are often subtle, and can be easily overlooked. They may include:

• Difficulty chewing or swallowing
• Muscle weakness affecting an arm or leg
• Slurred and nasal speech
• Twitching, cramping, or stiffness of muscles.

These ALS symptoms then develop into more obvious weakness or atrophy of the muscles. The causes of ALS disease are unknown, and it has no cure. However, certain medications can relieve ALS symptoms and sometimes prolong survival.

Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is a genetic disease that causes weakness and atrophy of the voluntary muscles in the arms and legs of infants and children. There are three types of spinal muscular atrophy, determined by the age of onset and the severity of symptoms:

• Type I is usually present at birth and has the most severe symptoms.
• Type II usually happens in early childhood and is less severe but still disabling.
• Type III happens as late as adolescence and may be only moderately disabling.

Although SMA has no cure, medicines and physical therapy can help treat symptoms. Life expectancy depends on the type of spinal muscular atrophy and how it affects breathing.

Other Degenerative Spinal Cord Diseases

Aside from spinal muscular atrophy and amyotrophic lateral sclerosis, some other degenerative spinal cord diseases include:

• Post-polio syndrome can affect survivors of polio even decades after their recovery from poliomyelitis.
• Progressive bulbar palsy affects functions such as swallowing, speaking and chewing.
• Progressive muscular atrophy mostly affects men, with symptoms including weakness that starts in the hands and then spreads into the lower body. (This disease often develops into ALS.)

Scientists are continuing to search for treatment options for degenerative spinal cord disorders, such as new drugs, growth factors (to help grow new nerve cells) and stem cells.

Resources

The ALS Association Staff. (2010). About ALS. Retrieved April 7, 2010, from http://www.alsa.org/patient/about.cfm?CFID=5803860