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What happens to the spinal cord after injury? Tools

Changes and types of injury

Many changes occur in the body after a spinal cord injury.

Initial changes

Some of the initial changes that occur immediately after your injury will not be permanent.

Spinal shock

Immediately after your injury, you go into what is called spinal shock. This means that you have no reflex activity or muscle tone below the level of your injury. Tendon reflexes in your muscles and autonomic reflexes to your organs and glands are absent and your bowel and bladder are flaccid and unresponsive to stimulation.

Spinal shock can last up to 6-8 weeks, although some spinal reflexes will reappear before this.

Neurogenic shock

If you have injured your spinal cord at T6 or above, you will go into neurogenic shock. In this injury there has been a major disconnection between your brain and your autonomic nervous system. This means your blood pressure, heart rate and body temperature is affected.

Neurogenic shock causes:
  • very slow heart rate (bradycardia)
  • low blood pressure (hypotension)
  • low body temperature (hypothermia)

These symptoms can be very severe and even life threatening, although it is likely that you will stabilise quickly. Temperature control and blood pressure regulation will need ongoing monitoring and management.

Permanent changes

Many permanent changes will take place in your body’s systems. These include:

  • changes or loss of ability to feel sensations such as touch, pressure and temperature below the level of your spinal cord injury
  • changes in or loss of ability to move parts of your body below the level of your spinal cord injury
  • changes in or loss of voluntary control of your bladder and bowel
  • changes in respiratory function if you have an injury in your thoracic and cervical spinal cord
  • changes in the functioning of your autonomic nervous system, which will affect your:
    • sexual function
    • bladder function
    • bowel function
    • blood pressure maintenance
    • temperature regulation

Paraplegia and quadriplegia

There are two categories of injury affecting ability to move and feel sensations.

Paraplegia

Your spinal cord injury is at T2 level or below. This has resulted in you losing, or partially losing, your ability to move and to feel sensations such as touch, pressure and temperature, in your lower limbs. Depending on the location of your injury parts of your trunk may also be affected.

Quadriplegia

Quadriplegia (also known as tetraplegia) means that your injury is between the C1-T1 levels of your spinal cord. This results in you losing either fully or partially the ability to move and to feel sensations such as touch, pressure and temperature, in your upper and lower limbs, as well as your trunk. The degree to which your upper body is affected will depend on your particular injury.

Variation in injuries

There is a great range of abilities and functional outcomes within both paraplegia and quadriplegia.

The International Standards for Neurological Classification of Spinal Cord Injuries, referred to as the ASIA Impairment Scale is used to classify injuries. See the American Spinal Injury Association (ASIA) website for more information.

Your spinal cord injury affects reflex activity to your muscles, bladder, bowel and sexual organs. The location of your injury affects how much reflex activity you will retain.

Upper motor neuron (UMN) spinal cord injury

You have an upper motor neuron (UMN) injury if your injury is above the conus medullaris, and your spinal nerves at L2-L5 and S1-S5 are intact. When these nerves are intact reflex activity is able to take place. This is also called reflex paralysis.

UMN injuries involve:

  • loss of voluntary movement below the level of your injury
  • loss of sensory perception (feeling) below the level of your injury
  • increased muscle tone, which often leads to spasm
  • retained reflexes after spinal shock subsides
  • reflex paralysis (spastic paralysis).

Lower motor neuron (LMN) spinal cord injury

You have an LMN injury if the damage to your spinal cord is at or below the conus medullaris and involves the spinal nerves from L2-L5 and S1-S5 levels, the cauda equina, and S2-4 levels. This is also called lesion or flaccid paralysis.

An aortic aneurysm bursting can cause lack of blood supply to any level of your spinal cord. This can result in damage to your whole spinal cord, including your conus medullaris. This means your reflex activity will also be disrupted (disconnected).

LMN injuries result in:

  • loss of voluntary movement below the level of your injury
  • loss of sensory perception (feeling) below the level of your injury
  • decreased or absent resting muscle tone
  • severe muscle wasting below the level of your injury
  • loss of reflexes below the level of your injury
  • flaccid paralysis

If your spinal cord injury is between the T12 and L2 vertebrae then the conus medullaris is likely to be damaged. This means you may have some reflex activity where other areas may have no tone or somewhere inbetween.