How the spinal cord has been damage is an important consideration when evaluating an injury. There are two types of injuries: complete and incomplete. Someone with a complete injury will have complete loss of muscle control and sensation below their level of injury and no motor or sensory function in the S4 or S5 area (anal area). An incomplete injury may result only in muscle paralysis, muscle weakening, or impaired sensation. If testing shows any evidence of function in the anal area, the injury is classified as incomplete. The extent of injury is defined by the American Spinal Injury Association (ASIA) Impairment Scale, as follows:
- A - Complete: No sensory or motor function is preserved in sacral segments S4-S5.
- B - Incomplete: Sensory, but not motor, function is preserved below the neurologic level and extends through sacral segments S4-S5.
- C - Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have muscle grade less than 3.
- D - Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have muscle grade greater than or equal to 3.
- E -
People with complete injuries recover, on average, 8% of lost function (21% if they received methylprednisolone). On average, people with incomplete injuries recover 59% of lost function (75% if they received methylprednisolone).
