Generalities:

Paralysis: loss or diminution of the motricity of some muscle or group of muscles. It may be of neuronal origin, due to some injury in some motor region of the brain. Trace all the motor areas of the cerebral cortex to find the active focus.

When the paralysis affects a single hemibody (half of the body) it is called hemiplegia, if it affects the four extremities it is called quadriplegia.

In other cases the paralysis may be due to damage to the rachis (radiculopathy) or damage of an afferent nerve.

Causes:

Brain damage due to stroke. Damage to some nerve by accident (trauma) or infection.