Paraplegia is an impairment in motor or sensory function of the lower extremities. The word comes from
Ionic Greek: παραπληγίη "half-striking". It is usually caused by
spinal cord injury or a
congenital condition such as
spina bifida that affects the neural elements of the spinal canal. The area of the spinal canal that is affected in paraplegia is either the thoracic, lumbar, or sacral regions. If four limbs are affected by paralysis,
tetraplegia or quadriplegia is the correct term. If only one limb is affected, the correct term is
monoplegia.