The term âcatapultâ is used to define a very wide variety of large machines for hurling projectiles and some of the more common variations include the trebuchet, which is a catapult that uses gravity and a seesaw effect to hurl its projectile.
A demyelinating disease is any condition that results in damage to the protective covering (myelin sheath) that surrounds nerve fibers in your brain and spinal cord.
Other causes. Other types of demyelinating disease and their causes include: Optic neuritis â inflammation of the optic nerve in one or both eyes. Neuromyelitis optica (Devic's disease) â inflammation and demyelination of the central nervous system, especially of the optic nerve and spinal cord.