Current status and future perspectives on stem cell transplantation for spinal cord injury

Table 1 American Spinal Cord Injury Association Impairment Scale improvement scale

A = Complete	No sensory or motor function is preserved in the sacral segments S4–S5
B = Sensory incomplete	Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-S5 (light touch or pin-prick at S4–S5 or deep anal pressure) AND no motor function is preserved more than three levels below the motor level on either side of the body
C = Motor incomplete	Motor function is preserved below the neurological level AND more than half of the key muscle functions below the neurological level of injury have a muscle grade less than 3 (grades 0–2)
D = Motor incomplete	Motor function is preserved below the neurological level AND at least half (half or more) of the key muscle functions below the neurological level of injury have a muscle grade ≥ 3
E = Normal	If sensation and motor function as tested with the ISNCSCI are graded as normal in all segments AND the patient has prior deficits, then the AIS grade is E. Someone without an initial SCI does not receive an AIS grade

Time from injury: Immediate: 0-2 h after the injury; acute: Early acute phase: 2-48 h; subacute: 2 d - 2 wk; intermediate: 2 wk - 6 mo; chronic phase: > 6 mo. AIS: American spinal injury association Impairment Scale; ISNCSCI: International Standards for Neurological Classification of SCI.