Spinal Cord Anatomy
Before discussing spinal cord injury, let’s briefly review the anatomy of the spinal cord. It may additionally be useful to review the anatomy of the cervical, thoracic, and lumbar spine.
The spinal or vertebral column—provides support for the body and protects the spinal cord. The spinal column includes vertebrae, intervertebral discs, and numerous muscles, tendons, and ligaments. The spinal column is divided into three regions—cervical (neck), thoracic (thorax), and lumbar (low back). There are seven cervical (C1-C7), twelve thoracic (T1-T12), and five lumbar vertebrae (L1-L5). Additionally, at the base of the spine, is the sacrum, which consists of 5 fused sacral segments (S1-S5).
The nervous system includes the brain, spinal cord, and spinal nerves. The brain is the master control for all body functions. The spinal cord serves as the main line of communication between the brain and the body. The spinal nerves relay messages to and from the spinal cord and other parts of the body. The vertebral column houses and protects the spinal cord and the spinal nerves. Sensory (allows for the ability to feel) and motor (allows for the ability to move) messages are relayed via the neural structures. Reflexes and the functions of the heart, lungs, gastrointestinal tract, urinary tract, are all controlled by the nervous system.
Details of Spinal Cord Injury
Injury to the spinal cord can result in a variable loss of function below the level of injury. A complete spinal cord injury means that there is total loss of sensory and motor function below the level of injury i.e. there will be no feeling or movement below the level of injury — depending on the level of injury, this can include loss of respiratory, bowel, and / or bladder control.
With an incomplete injury, some function will still remain i.e. there is partial damage to the spinal cord and there will be some variable loss of feeling and movement depending on how much damage has been done to the spinal cord. Again, depending on the level of injury, there can be variable loss of respiratory, bowel, and / or bladder control.
There are many causes of spinal cord injury. The most common causes are accidents like automobile, diving, and falls. There are many disease processes that can also cause spinal cord injury as well such as multiple sclerosis, amyotrophic lateral sclerosis (ALS), and tumors.
The level of injury determines the functional loss. This can be quite complex to understand. For example, a complete injury at the thoracic level will cause numbness below that level, loss of functions in the legs, and loss of bowel and bladder control. A complete injury at the cervical (neck) level will cause numbness below that level (i.e. potentially arms, all the way down to the feet), loss of function in the arms (variable depending on specific level of injury in the cervical spine), loss of function in the legs, loss of bowel and bladder control, and potentially loss of the ability to breath (depending on the level of injury in the cervical spine).
Paraplegia refers to the loss of function in the legs. Quadriplegia refers to loss of function in both the arms and legs.
Spinal shock may occur immediately after a sudden spinal cord injury. Spinal shock results in complete loss of reflexes, movement and feeling below the level of injury. The return of reflex activity signals the end of spinal shock. Typically this takes about 48-72 hours but may take longer. Only once this occurs can the level of actual spinal cord injury be assessed.
The prognosis (how well you do after your injury) of spinal cord injury is highly variable.
Things to know about your spinal cord injury
If you or a loved one have experienced a spinal cord injury there are many questions to ask your doctors regarding your injury so that you can make the necessary lifestyle adjustments and plan accordingly. Most often, particularly in the setting of an accident, surgery is required to stabilize the spine. Following surgery, typically long-term rehabilitation is needed to maximize recovery.
Here are some questions to keep in mind:
What is the level of spinal cord injury?
Is it a complete or incomplete injury?
Was surgery performed? If so, what type of surgery?
What are the rehabilitation plans?
Will the injury affect my toileting habits?
Surgery to the Spinal Column
In many cases of spinal cord injury, surgery may be needed to stabilize the spinal column to prevent further injury to the spinal cord. This type of stabilization surgery is called a spinal fusion. Oftentimes, a decompression surgery must be performed at the same time to take pressure off of the cord. In this type of procedure, the bone that is compressing the spine is removed. Damage to the spinal cord may continue to occur if the spine is unstable or if pressure remains on the cord. Ultimately, the type of surgery needed will depend on the type and level of injury.
For cervical injuries, screws and rods are typically used to stabilize the spine. Sometimes, plate, screws, and cages can also be used to stabilize the spine from the front. Finally, a halo device may be used in some instances to stabilize certain types of cervical spine injuries. The halo is worn for 8 to 12 weeks (or sometimes longer) while healing occurs.
For thoracolumbar injuries, similarly, screws and rods can be used to stabilize the spine. Sometimes, the surgeon may need to go through the chest or the abdomen to stabilize the front of the spine with a cage.
Rehabilitation will start while you are in the hospital, typically immediately after surgery. Oftentimes, prolonged rehabilitation is needed to help with the recovery process.
Oftentimes, following fusion surgery, you may be required to wear a brace (thoracolumbar spine) or a cervical collar for 6-12 weeks when you are out of bed and mobile. The brace and collar give your spine extra support while it heals.
Typically you will be seen at 2 weeks post-operatively to check the status of your wound and have any non-absorbable sutures removed.
At 6 weeks and 3 months typically you will be seen again in clinic. Xrays will be taken to assess the status of your spinal fusion and to make sure things are healing well.
Glossary for Spinal Cord Injury
- Cauda Equina
- The bundle of nerves that branch off of the end of the spinal cord and carry messages about bowel, bladder, and lower extremity function. It is located below the lumbar area of the spinal cord and looks like a horse’s tail.
- Referring to the neck area, where 8 cervical nerves carry messages for movement and feeling to the arms, the hands, the fingers and the diaphragm.
- The main muscle responsible for breathing. It is located under the rib cage.
- Referring to the lower area of the back. The 5 lumbar nerves that exit here carry messages for movement and feeling to the lower extremities
- Motor Nerve
- A nerve which controls muscles, thereby controlling movement
- The electrical wire of the body. Connects the brain and spinal cord with parts of the body; carries messages for movement and sensation.
- Nervous System
- Includes the brain, spinal cord, and nerves. It controls almost all body functions.
- Loss of movement and sensation.
- Paraplegia refers to the loss of function in the legs.
- Quadriplegia refers to loss of function in both the arms and legs.
- Spinal Reflex
- Movement of a muscle caused by a signal (pain, heat, pressure). The relaying of messages goes from the muscle to the spinal cord and then back to the muscle without ever going to the brain.
- Sacrum (tailbone)
- The triangular shaped bone at the base of the spine
- Sensory Nerve
- A nerve which carries sensory (touch, pressure, pain, temperature) messages.
- Spinal Column
- The spinal or vertebral column—provides support for the body and protects the spinal cord. The spinal column includes vertebrae, intervertebral discs, and numerous muscles, tendons, and ligaments.
- Spinal Cord
- An extension of the brain into the spine. Carries messages about movement and feeling to and from the brain.
- Spinal (Cerebrospinal) Fluid
- Fluid which flows around the brain and spinal cord protecting them from injury.
- Spinal Shock
- A period of time when reflexes, movement and feeling are absent below the level of injury.
- Referring to the upper and mid back area
- The individual bones which make up the vertebral column