A 22-year-old sustains a diving injury with C5–C6 dislocation. ASIA (American Spinal Injury Association) impairment scale assessment reveals no motor or sensory function below C6, including in S4–S5 dermatomes. What is the ASIA grade and the clinical significance?
- A ASIA A — motor and sensory complete injury; no voluntary anal contraction or perianal sensation ✓
- B ASIA B — sensory incomplete; some sacral sensation preserved below the neurological level
- C ASIA C — motor incomplete; more than half of key muscles below the NLI have strength <3
- D ASIA D — motor incomplete; more than half of key muscles below the NLI have strength ≥3
Correct answer: A. ASIA A — motor and sensory complete injury; no voluntary anal contraction or perianal sensation
Explanation
ASIA A (complete) is defined by absence of all motor and sensory function in the sacral segments S4–S5, including no voluntary anal contraction and no light touch or pin-prick sensation in the perianal zone. S4–S5 testing is the critical determinant of completeness. ASIA B preserves some sacral sensory function below the neurological level. ASIA C and D indicate motor incomplete injuries with varying degrees of preserved motor function below the lesion. ASIA A carries the worst prognosis for neurological recovery.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.