ALS, Part 1

With the "Ice Bucket Challenge" going viral online, let us discuss the disease behind this fund-raising campaign.

According to medical dictionary, amyotrophic lateral sclerosis (ALS)—also referred to as "Lou Gehrig's disease" in the United States — is a neurodegenerative disorder. This is also referred to as "Motor Neurone Disease" (MND) in the British Commonwealth.  ALS is characterized by muscle spasticity (tight and stiff muscles), rapidly progressive weakness due to muscle atrophy, and difficulty in speaking (dysarthria), swallowing (dysphagia), and breathing (dyspnea). 

In the U.S., more than 5,600 are diagnosed every year, and up to 30,000 Americans are currently affected. ALS is responsible for 2 deaths per 100,000 people per year.

The survival time from onset to death is 39 months, and only 4% survive longer than 10 years. Rare cases survive 50 years or more (like physicist Stephen Hawking). Most die from respiratory failure, usually within three to five years from onset of symptoms.

The disorder causes the motor neurons to degenerate and impulses to the muscle fibers can no longer be sent, thus the inability to move the muscles.  About 75% of people contracting the disorder experience "limb onset," i.e., first symptoms in the arms or legs. Patients with the leg onset form may experience awkwardness when walking or running or notice that they are tripping or stumbling, often with a "dropped foot" which drags gently along the ground. Arm-onset patients may experience difficulty with tasks requiring manual dexterity such as buttoning a shirt, writing, or turning a key in a lock.

The muscles then begin to atrophy and limbs begin to look “thinner.” Persons with this disorder may ultimately lose the ability to initiate and control all voluntary movement, though bladder and bowel function and the muscles responsible for eye movement are usually spared until the last stages of the disorder.  The eye movements remain unaffected largely until the later stages due to differences in the extra-ocular muscles compared to the skeletal muscles that are initially and readily affected.

Next week we shall continue discussing ALS (possible causes and treatment)  – J.P.