Amyotrophic Lateral Sclerosis:

A	=	absence of
myo	=	muscle
trophic	=	nourishment
Lateral	=	side (of spine)
Sclerosis	=	hardening

Dr. Jean-Martin Charcot, a French neurologist, published the first full account of this disease in 1874. ALS, also known as Charcot's Disease, Lou Gehrig's Disease and Motor Neuron Disease, is a major neurological disorder. In Canada it is the most common cause of neurological death on an annual basis.

ALS destroys motor neurons that are an important link in the nervous system, and through which the brain controls the voluntary muscles throughout the body.

Leg and foot muscles are controlled by motor neurons in the lower spinal cord. Arm, hand and finger muscles are controlled by motor neurons in the upper spinal cord. Speaking, swallowing and chewing are controlled by motor neurons in the brain stem.

ALS does not affect the five senses of sight, hearing, taste, smell and touch, nor does it normally affect the mind, eye muscles, heart, bladder, bowel, or sexual muscles. There is no possibility that ALS is contagious.

ALS strikes about 6 people per 100,000 per year. Between 1,500 and 2,000 people in Canada currently have ALS. Although it most commonly occurs between the ages of 40 and 70, it can also occur in older people, and rarely in teenagers.

The most common form of ALS is called Sporadic ALS. In addition, about 5% of patients have an inherited variety called Familial ALS. Until recently, an abnormally high incidence of ALS was observed in the Western Pacific (Guam, Kii Peninsula of Japan, Papua New Guinea). As a result of extensive research into Guamanian ALS, it is now thought that these high incidence rates were due to specific dietary toxins (for example, Aluminium, cycasin). With the Westernization of this region, and the reduced dependency on traditional foodstuffs, dramatic declines in the incidence of ALS in this region have occurred.

Symptoms are what you experience, while signs are what your doctor can see. The early symptoms of ALS may seem rather vague. They can include tripping, dropping things, slurred or "thick" speech, and muscle cramping, weakening, and twitching. Some people with these early symptoms may tend to assume that they are normal signs of aging. As the disease progresses, the muscles of the trunk of the body are affected. Weakness of the breathing muscles develops slowly over months or years.

For some people, the muscles for speaking, swallowing or breathing are the first to be affected. This is known as Bulbar ALS. The term “bulbar” refers to the motor neurons located in the bulb region of the brain stem, that control the muscles used for chewing, swallowing, and speaking. ALS symptoms, and the order in which they occur, vary from one person to another.

The rate of muscle loss can vary significantly from person to person, with some patients having long periods with very slow degeneration. Although the average life expectancy of newly diagnosed people is between 3 and 5 years, 20% live more than 5 years, and 10% live more than 10 years. Being a progressive disease, ALS may spread throughout the body over time, and at some point in this process, may involve the muscles required for breathing.

ALS can be difficult to diagnose in the early stages, when symptoms may mimic other conditions. However, there are clinical signs that can be indicative of a wasting of motor neurons in either the upper or lower portion of the spine.

As such, clinicians familiar with ALS usually see the following signs of lower and upper motor neuron degeneration:

Lower Motor Neuron Degeneration

• muscle weakness and atrophy
• involuntary contraction of muscle fibres
• muscle cramps
• weakened reflexes
• flaccidity (decreased muscle tone)
• difficulty swallowing
• disordered articulation
• shortness of breath at rest

Upper Motor Neuron Degeneration

• muscle stiffness or rigidity
• emotional lability (decreased ability to control emotions)

Some may assume that these are signs of normal aging. Over time, as muscles continue to weaken, and the weakening spreads throughout the body, it becomes more apparent that the cause is ALS.

In addition to a physical examination, people are often given an EMG, blood tests, a MRI (Magnetic Resonance Imaging), and other tests to search for the presence of other diseases that can look like ALS.

Doctors who do not usually see people with ALS may be reluctant to suggest it as a possible diagnosis. They normally refer the person to a neurologist. Telling someone and his or her family that the person may have ALS requires a sensitive, understanding and compassionate manner. People should also be told about the disease, current research and drug trials, as well as about support services and the ALS Society in their province.