The late Stephen Hawking was an incredible human for a number of reasons, but not least for his deep perseverance despite the terminal diagnosis he was given as a young man.
“My expectations were reduced to zero when I was 21,” Hawking famously said. “Everything since then has been a bonus.” But how, exactly, did Hawking beat the odds when he was diagnosed with amyotrophic lateral sclerosis (ALS) in 1963?
As ALS is the most common form of motor neurone disease (MND), the terms are often used interchangeably, but this is not strictly accurate as there are other variants of MND.
In general, it is a progressive neurodegenerative disease that affects the nerve cells in the front of the brain and in the spinal cord. These cells are responsible for moving the muscles in your body. Over time, the death of these neurons leads to a loss of control of not only your limbs, but also your ability to swallow and even breathe. But as is usually the case, the disease is not quite that straightforward.
For a start, each variety of MND manifests in a slightly different way. For example, one rare subtype is known as progressive muscular atrophy (PMA), or Duchenne-Aran muscular atrophy, and primarily affects the motor neurons found in the spinal cord but not the brain.
Then there is primary lateral sclerosis (PLS), which again is not particularly common. In contrast to PMA, it generally tends to affect the motor neurons found in the brain, which degenerate and die, but not those in the spinal cord.