Hawking suffers from a rare early-onset , slow-progressing form of amyotrophic lateral sclerosis ( ALS ) , also known as motor neurone disease or Lou Gehrig 's disease , that has gradually paralysed him over the decades .
Hawking suffers from a rare early-onset , slow-progressing form of amyotrophic lateral sclerosis ( ALS ) , also known as motor neuron disease or Lou Gehrig 's disease , that has gradually paralyzed him over the decades .