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 Spinal cord injuries (SCI’s) can be divided into two main categories, complete and incomplete injuries. They may be further classified into several categories according to the extent of motor and sensation loss using the international classification system of the American Spinal Cord Association (ASIA). The classification of a patient’s injury is not static, and may change during recovery.
Complete Spinal Cord Injury
It is very rare that a patient’s spinal cord is cut and severed. Complete SCI is caused by bruising, pressure on the spinal cord, and loss of blood supply to the cord. The result is entire loss of movement and sensation below the level of the injury.
Incomplete Spinal Cord Injury
Incomplete SCI does not result in complete loss of movement and sensation below the level of the injury; patients may have varying degrees of both. There are several subtypes of incomplete SCI:
Anterior Cord Syndrome-Injury occurs in the anterior, or front, of the spinal cord and affects the motor and sensory pathways in the affected area. Patients suffer loss of movement and sensation, although some sensations may still be felt that travel through still-intact pathways.
Central Cord Syndrome-This injury occurs in the center of the cervical (uppermost) area of the spinal cord and causes an interruption in the brain and spinal cord’s ability to communicate to control movement. Patients experience weakness or paralysis in their arms and some loss of sensory reception. Legs are generally much less affected than the arms. Spontaneous recovery is possible. People often improve in the first 6 weeks after injury.
Brown-Sequard Syndrome-In this type of SCI, injury can occur on either side of the spinal cord, resulting in loss of sensation on the side of the body below the level of the injury. Patients lose temperature and pain sensation on the opposite side of the injury due to the crossing of these pathways in the spinal cord.
Injuries to Nerve Cells-This type of SCI results in the loss of sensory and motor function only to that area of the body that is affected by the injured nerve root. Symptoms vary among patients, depending on which nerve root is affected and where it is located.
Spinal Contusions-Contusions are the most common type of SCI. In this type of injury the cord is bruised and, as a consequence, there is inflammation and bleeding from blood vessels near the injury. This type of injury results in temporary debilitation of the spinal cord, usually lasting 1 to 2 days. The injury may be complete or incomplete.
Classification
The American Spinal Cord Injury Association (ASIA) has developed an international classification based on neurological levels, touch and pinprick sensation in each dermatome (an area of skin that has sensation from a single nerve root of the spinal cord), and the strength of 10 key muscles on each side of the body.
A: complete spinal cord injury; no motor or sensory function is preserved in the sacral segments S4-S5
B: incomplete spinal cord injury; sensory but not motor function is preserved below the neurological level; includes sacral segments S4-S5
C: incomplete spinal cord injury; motor function is preserved blow the neurological level; more than half of key muscles below the neurological level have a muscle grade of less than 3
D: incomplete spinal cord injury; motor function is preserved below the neurological level; at least half of the key muscles below the neurological level have a muscle grade of 3 or more
E: normal *it is possible to have SCI and neurological deficit with completely normal motor and sensory scores as the scale may not be sensitive for subtle injury, spasticity, pain or numbness.
The ASIA scale has ( click here to see ASIA scale worksheet) been adopted by almost every major spinal cord injury association, which has resulted in more consistent and standardized classification worldwide. |
