Spinal Cord Injury (SCI): ASIA Impairment Scale (AIS) and Level-by-Level Functional Goals
In short
Neurological recovery after spinal cord injury depends on complete versus incomplete preservation. Learn the ASIA Impairment Scale, motor sensory levels, and functional mobility goals.
In this guide (5 sections)
The International Standards for Neurological Classification of SCI (ISNCSCI)
Spinal Cord Injury (SCI) results in catastrophic disruption of motor, sensory, and autonomic communication between the brain and periphery, caused by traumatic vertebral fractures, disc herniation, or non-traumatic vascular and inflammatory lesions.
Accurate neurological classification under the American Spinal Injury Association (ASIA) International Standards defines the exact Neurological Level of Injury (NLI) and distinguishes complete from incomplete injuries.
Examination requires testing 28 sensory dermatomes bilaterally for pinprick and light touch, alongside 10 key muscle myotomes (C5 to T1 for upper limbs, L2 to S1 for lower limbs).
The ASIA Impairment Scale (AIS Grades A to E)
The AIS grade is determined by sacral sparing at S4-S5: deep anal pressure (DAP) sensation and voluntary anal sphincter contraction (VAC).
| AIS Grade | Classification Category | Neurological Definition | Functional Prognosis for Ambulation | |
|---|---|---|---|---|
| Grade A | Complete Injury | No sensory or motor function preserved in sacral segments S4-S5 | Less than 3% chance of recovering functional community ambulation. | |
| Grade B | Sensory Incomplete | Sensory preserved below NLI and at S4-S5; zero motor function below NLI | Approximately 30 to 40% may regain some motor function over 12 months. | |
| Grade C | Motor Incomplete | Motor preserved; more than half key muscles below NLI have grade < 3 | Up to 50% recover functional ambulation with assistive orthotics. | |
| Grade D | Motor Incomplete | Motor preserved; at least half key muscles below NLI have grade >= 3 | Over 75% achieve independent household or community ambulation. | |
| Grade E | Normal Function | Sensory and motor functions test completely normal across all segments | Normal functional capacity; may have residual hyperreflexia. |
Level-Specific Functional Expectations (C1 to L5)
Functional independence milestones correlate directly with the lowest preserved motor segment.
Patients with high cervical lesions (C1 to C4) require electric power wheelchairs and respiratory support; C5 preserves elbow flexion permitting adapted eating; C6 preserves wrist extension, establishing functional tenodesis transfers; C7 preserves triceps extension, enabling independent push-up wheelchair transfers.
Thoracic paraplegia (T1 to T12) achieves complete independence in manual wheelchair propulsion and slide-board car transfers. Lumbar lesions (L2 to S1) achieve functional walking with Ankle-Foot Orthoses (AFOs) or forearm crutches.
- C6 Tenodesis Preservation: Never aggressively stretch finger flexors with the wrist extended; preserving natural finger flexor tendon tightness provides functional grasp.
- Pressure Relief Protocol: Perform wheelchair push-up pressure relief lifts for 30 seconds every 20 minutes to prevent sacral and ischial pressure ulcers.
- Standing Frame Bone Density Loading: Utilize passive standing frames 45 minutes daily, 5 days weekly, to attenuate neurogenic osteopenia and maintain bone mineral density.
- Locomotor Body-Weight Support Training: Incomplete AIS C and D injuries benefit from early robotic or harness-supported treadmill walking to stimulate spinal central pattern generators (CPGs).
Indian Accessibility and Societal Realities
In Indian cities, pervasive lack of wheelchair ramps, narrow bathroom doors, and high threshold sills (chaukhat) isolate SCI individuals inside their homes.
Physiotherapists provide architectural barrier modification plans, train wheelies to conquer curbs, and guide families on modified accessible commodes.
Frequently Asked Questions
What is the spinal shock phase after SCI?
Spinal shock is the temporary complete loss of all reflex, motor, and autonomic function below the level of injury lasting days to weeks. Resolution is signaled by the return of the bulbocavernosus reflex.
Can an ASIA A complete injury become incomplete?
Fewer than 5 percent of true ASIA A complete injuries convert to incomplete status after spinal shock has resolved. However, strengthening preserved muscle segments enables extraordinary functional independence.
Why is standing in a frame important if a patient cannot walk?
Passive standing loads the long bones of the legs, slowing calcium resorption, preventing kidney stones, improving bowel and bladder motility, and reducing lower limb spasticity.
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