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American Spinal Injury Association (ASIA) Impairment Scale

American Spinal Injury Association (ASIA) impairment scale

The American Spinal Injury Association (ASIA) impairment scale or AIS describes a person's functional impairment as a result of a SCI. This scale indicates how much sensation a person feels after light touch and a pin prick at multiple points on the body and tests key motions on both sides of the body.

LT = light touch; PP = pin prick; DAP = deep anal pressure; AIS = ASIA Impairment Scale; NLI = neurologcal level of injury

  • Grade A = Complete. No sensory or motor function is preserved in the sacral segments S4-5.
  • Grade B = Sensory Incomplete. Sensory but no motor function is preserved below the neurological level and includes the sacral segments S4-5 (LT or PP at S4-5 or DAP), and no motor function is preserved more than three levels below the motor level on either side of the body.
  • Grade C = Motor Incomplete. Motor function is preserved at the most caudal sacral segments for voluntary anal contraction OR the patient meets the criteria for sensory incomplete status (sensory function preserved at the most caudal sacral segments (S4-S5) by LT, PP or DAP), and has some sparing of motor function more than three levels below the ipsilateral motor level on either side of the body. (This includes key or non-key muscle functions to determine motor incomplete status.) For AIS C – less than half of key muscle functions below the single NLI have a muscle grade ≥ 3.
  • Grade D = Motor Incomplete. Motor incomplete status as defined above, with at least half (half or more) of key muscle functions below the single NLI having a muscle grade ≥ 3.
  • Grade E = Normal. If sensation and motor function as tested with the ISNCSCI are graded as normal in all segments, and the patient had prior deficits, then the AIS grade is E. Someone without an initial SCI does not receive an AIS grade.
Muscle Function Grading
0 Total paralysis
1 Palpable or visible contraction
2 Active movement, full range of motion (ROM) with gravity eliminated
3 Active movement, full ROM against gravity
4 Active movement, full ROM against gravity and moderate resistance in a muscle specific position
5 (normal) Active movement, full ROM against gravity and full resistance in a functional muscle position expected from an otherwise unimpaired person
5* (normal) Active movement, full ROM against gravity and sufficient resistance to be considered normal if identified inhibiting factors (i.e. pain, disuse) were not present
NT Not testable (i.e. due to immobilization, severe pain such that the person cannot be graded, amputation of limb, or contracture of > 50% of the normal range of motion)
Sensory Grading
0 Absent
1 Altered, either decreased/impaired sensation or hypersensitivity
2 Normal
NT Not testable

Literature