There are two main classifications of spinal cord injury: complete and incomplete. These terms refer to the levels of sensation and movement that a person may or may not have after the injury.
People with a complete spinal cord injury cannot move or feel anything at or below the area where the trauma occurred. Those with an incomplete spinal cord injury may have some sensation and movement below the level of the injury.
In this article, we discuss the similarities and differences between both types of injuries.
A complete spinal cord injury occurs when a person loses all sensory and motor function below the level of the spinal cord injury. When a person with a spinal cord injury retains some function below the level of the injury, they have an incomplete spinal cord injury.
The American Spinal Injury Association (ASIA) established a grading system called the ASIA Impairment Scale to describe the severity of spinal cord injuries. The system uses the letters A through E and is as follows:
- ASIA A: complete spinal cord injury with no sensory or motor function
- ASIA B: incomplete sensory function with complete loss of motor function
- ASIA C: incomplete motor function with some movement, but fewer than half of the muscle groups can lift against gravity with a full range of motion
- ASIA D: incomplete motor function with more than half of the muscle groups able to lift against gravity
- ASIA E: normal
Spinal cord injuries, whether complete or incomplete, can cause a loss of muscle function and sensation.
With both types of injuries, the injury may not completely sever the spinal cord.
According to the American Association of Neurological Surgeons, almost 50% of all spinal cord injuries are complete.
Complete spinal cord injuries result in a total loss of motor function and sensation below the level of the injury. People with complete spinal cord injuries will have a loss of muscle function and sensation on both sides of the body.
People with incomplete spinal cord injuries may retain varying degrees of muscle movement and sensation. A person with an incomplete injury may be able to move one arm or leg more than the other. They may also have more functioning on one side of the body than on the other.
Research suggests that people with an incomplete spinal cord injury have a higher chance of recovering from a loss of motor and sensory function in the affected limbs than those with a complete spinal cord injury.
People with spinal cord injuries require immediate medical attention. In the emergency room, doctors will check for movement or sensations at or below the level of the injury.
The doctor may use an X-ray, CT scan, and MRI scan to diagnose a spinal cord injury.
Swelling around an incomplete injury may present symptoms of a complete injury. However, once the swelling goes down, after about 7–10 days, the doctor can distinguish between the two types of injuries.
A neurologist will then conduct a complete neurological examination, in which they will usually:
- ask the person questions about their symptoms and other health conditions
- look for visible signs of a medical condition
- carry out a physical examination
A doctor may then perform various tests to evaluate the function of a person’s nerves regarding movement and sensation.
The symptoms of a spinal cord injury depend on the location of the injury. There are four sections of the spinal cord:
- cervical spine (vertebrae C1 through C7, which contain a total of eight cervical nerve roots)
- thoracic spine (vertebrae T1 through T12)
- lumbar spine (vertebrae L1 through L5)
- sacral spine (vertebrae S1 through S5)
Each of the four sections controls different parts of the body. An injury to the spinal cord affects the parts of the body that nerves in and below the affected area control.
Following a spinal cord injury, a person may experience pain. An older study reports that about one-third of people who have a spinal cord injury experience severe pain. People may also experience fatigue.
Other symptoms that people with a spinal cord injury may report include:
- memory problems
- vision problems
- perceived weakness
Spinal cord injuries may occur when the vertebrae that normally protect the spinal cord become compromised. When vertebrae break or become dislocated, the fragments of bone may apply harmful pressure to the nerves in the spinal cord.
According to the National Institute of Neurological Disorders and Stroke, motor vehicle accidents and catastrophic falls are the most common causes of spinal cord injuries.
Other possible causes of these injuries include:
Treatment and recovery time depend on the type of spinal cord injury that the person has sustained. The medical team will assess the person’s case and develop a suitable treatment plan and recovery time frame.
At the scene of the accident, emergency personnel will immobilize a person with a suspected spinal cord injury to prevent any further damage.
Surgery is a standard treatment for spinal cord injuries. It is usually the first response in cases where there is a risk of further damage. Surgery may involve the removal of objects compressing the spinal cord nerves, such as herniated disks, fractured vertebrae, or bone fragments.
Treatment after surgery may include:
People who have a spinal cord injury should see their healthcare team regularly. These professionals can help manage complications, recommend adaptive equipment, and improve a person’s quality of life.
As there have been many advances in medical procedures and patient care, people with spinal cord injuries often survive these traumatic events and live for decades.
Both complete and incomplete spinal cord injuries occur due to damage to the spinal cord. The main difference is the level of sensation and movement that the person retains after the injury.
A complete spinal cord injury causes a total loss of muscle movement and sensation at the injured site and below.
A person with an incomplete spinal cord injury retains some level of function below the level of the injury.
A doctor will be able to tell the difference and diagnose the type of injury by looking at the results of imaging tests and a neurological examination.