Paraplegia

Paraplegia is a condition where the lower half of a patient's body is paralyzed and cannot move. It is usually the result of spinal cord injury or a congenital condition such as spina bifida, but polyneuropathy may also result in paraplegia. If the arms are also paralysed, quadriplegia is a more appropriate diagnosis.

Causes

Central nervous system: Any disease process affecting the pyramidal tract of the spinal cord from the thoracic spine downward may lead to paraplegia, as this structure transmits "instructions" for movement from the brain to the anterior horn. This is the most common cause of paraplegia. It is usually spastic: it results in an increased muscle tone in the affected limbs. Causes range from trauma (acute spinal cord injury: transsection or compression of the cord, usually by bone fragments from vertebral fractures) to tumors (chronic compression of the cord), myelitis transversa and multiple sclerosis. Sometimes, paralysis of both legs can result from injury to the brain (bilateral injury of the motor cortex controling the legs, e.g. due to a stroke or a brain tumor).

Related Topics:
Central nervous system - Pyramidal tract - Thoracic spine - Brain - Anterior horn - Spastic - Muscle tone - Trauma - Spinal cord injury - Vertebra - Tumor - Myelitis transversa - Multiple sclerosis - Paralysis - Motor cortex - Stroke - Brain tumor

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Peripheral nervous system: Rarer is the type which is caused by damage to the nerves supplying the legs. This form of damage is not usually symmetrical and would not cause paraplegia, but polyneuropathy may cause paraplegia if motor fibres are affected. While in theory the arms should also be affected, the fibres that supply the legs are longer and hence more vulnerable to damage.

Related Topics:
Peripheral nervous system - Nerve - Polyneuropathy

~ ~ ~ ~ ~ ~ ~ ~ ~ ~