In this file photo taken on February 8, 2015, British scientist Stephen Hawking arrives for the BAFTA British Academy Film Awards at the Royal Opera House in London.
Renowned British physicist Stephen Hawking, whose mental genius and physical disability made him a household name and inspiration across the globe, has died at age 76, a family spokesman said on March 14, 2018. / AFP PHOTO / Justin TALLIS
What is amyotrophic lateral sclerosis, the root of Stephen Hawking’s death?
The Star/Asia News Network / 11:02 AM March 30, 2018
Stephen Hawking was probably the most famous man to have ALS, and I sort of understand what it is. But what does ALS stand for?
ALS stands for Amyotrophic Lateral Sclerosis. It is also called Lou Gehrig’s disease, after the famous American baseball player who had it.
It is a type of motor neuron disease that is progressive, and slowly destroys nerve cells and causes disability.
What is motor neuron disease? Actually, what is a motor neuron in the first place?
A motor neuron is a nerve cell that has a cell body located in either the spinal cord, brainstem or motor cortex of the brain.
The word “motor” here denotes action. Motor neurons control the organs and muscles that act or do things that involve “action”, e.g. walking, talking, swinging your arms, producing saliva etc.
This is opposed to sensory neurons that sense touch, heat, cold, pressure and vibrations coming from your skin.
A motor neuron constitutes a cell body that projects into an axon (nerve fibre).
Motor neuron disease constitutes a group of conditions that affect these motor neurons.
There are five main types of motor neuron disease, and ALS is one of them.
What are the other types of motor neuron disease?
ALS is the most common type, and it affects the muscles in your arms, legs, mouth and respiratory system.
It usually causes death in three to five years because it ultimately shuts down the muscles of your breathing system, but some people – like Hawking – live for years and years.
Another type is Progressive Bulbar Palsy (PBP). This one involves the brainstem, leading to choking, difficulty in speaking, eating and swallowing.
Many people with ALS have PBP too.
Yet another type is Progressive Muscular Atrophy (PMA). This one is a variation of ALS that slowly causes your arm, leg and mouth muscles to waste.
The rarest of them all is Primary Lateral Sclerosis (PLS), which advances very slowly. Luckily, this one does not kill you.
Lastly, there is Spinal Muscular Atrophy (SMA), that affects the trunk, arms and legs of children.
What causes ALS? Is it inherited?
Only 5% to 10% of cases are inherited.
But, to this day, doctors still don’t know what causes most cases of ALS.
Researchers have postulated that it may be caused by gene mutations, or a chemical imbalance, or even a “disorganised” body immune response.
However, there seems to be some risk factors for ALS. They are:
• Hereditary: If you have ALS, there’s a 50/50 chance your children may have ALS.
• Age: ALS is commonest between the ages of 40 and 60.
• More men than women get it.
• Smoking, especially for women.
• Exposure to environmental toxins.
• Military service. It’s unclear exactly how this can trigger ALS, but there seems to be a link.
How do the symptoms of ALS start?
First, you may find it difficult to walk. You may trip and fall down stairs. You find yourself getting clumsier.
The weakness is usually more noticeable in your legs, feet or ankles at first. Then this progresses to weakness in your hands. You can’t seem to hold a pen or write.
Some people notice this in their hands first, then legs, and vice versa in others.
Later, you may have slurred speech or trouble swallowing.
You may have muscle cramps and twitching in your arms, shoulders and tongue. You can’t hold your head or back up.
All this is happening because your motor neurons are being affected. Sensation is completely intact.
As the disease progresses, you won’t be able to speak, chew or swallow, and ultimately breathe.
Your bladder control and bowels are completely normal because these go through the autonomic nerve system and not the motor neurons.
Your brain power is completely normal.
Is it possible to live with ALS?
Yes. Nowadays, you can live with ALS for quite a long time. To help you breathe, there is assisted breathing with devices, or even a full-time ventilator.
There are communication devices to help you communicate with others, like the one Hawking used. He actually wrote entire books this way! But you will need 24-hour nursing care.