NCS Spinal Cord Injury 2 — Questions and Answers
Question 1: According to the ASIA Impairment Scale, an ASIA A classification indicates:
- Incomplete injury with only sensory function below NLI
- No sensory or motor function preserved in sacral segments S4-S5 (Correct answer)
- Motor function preserved with more than half key muscles graded ≥3
- Incomplete injury with normal sensory and motor function
Correct answer: No sensory or motor function preserved in sacral segments S4-S5
ASIA A is a complete injury with no motor or sensory function preserved in the sacral segments S4-S5.
Question 2: The Zone of Partial Preservation (ZPP) is documented only in which ASIA classification?
- ASIA A (Correct answer)
- ASIA B
- ASIA C
- ASIA D
Correct answer: ASIA A
ZPP applies only to ASIA A (complete) injuries, referring to dermatomes and myotomes below the neurological level that retain partial innervation.
Question 3: Which key muscle group is tested to determine a C6 motor level per ASIA standards?
- Elbow flexors (biceps brachii)
- Wrist extensors (ECRL, ECRB) (Correct answer)
- Elbow extensors (triceps)
- Finger flexors (FDP to middle finger)
Correct answer: Wrist extensors (ECRL, ECRB)
Wrist extensors (ECRL and ECRB) are the C6 key muscles in the ASIA standardized motor examination.
Question 4: Sacral sparing, which determines whether a spinal cord injury is complete or incomplete, requires preservation of:
- Any reflex activity in the S1-S3 nerve roots
- Perianal sensation, voluntary anal contraction, or great toe flexion (Correct answer)
- Bilateral lower extremity motor function below injury level
- Bladder and bowel reflex activity only
Correct answer: Perianal sensation, voluntary anal contraction, or great toe flexion
Sacral sparing is confirmed by perianal sensation, voluntary anal sphincter contraction, or voluntary great toe flexion, indicating an incomplete injury.
Question 5: What distinguishes an ASIA C from an ASIA D incomplete spinal cord injury?
- ASIA D requires voluntary anal sphincter contraction while ASIA C does not
- In ASIA C more than half of key muscles below NLI grade <3; in ASIA D more than half grade ≥3 (Correct answer)
- ASIA C has sensory function only; ASIA D has both sensory and motor function
- ASIA D injuries occur exclusively at the cervical level
Correct answer: In ASIA C more than half of key muscles below NLI grade <3; in ASIA D more than half grade ≥3
ASIA C = more than half of key muscles below NLI grade less than 3; ASIA D = more than half grade ≥3 (antigravity or better).
Question 6: The ASIA standard key sensory point for the L3 dermatome is located at the:
- Medial malleolus
- Medial femoral condyle (Correct answer)
- Dorsum of the foot at the third metatarsal head
- Lateral aspect of the popliteal fossa
Correct answer: Medial femoral condyle
The ASIA standard sensory testing point for L3 is the medial femoral condyle.
Question 7: Which key muscle is used to determine the L4 motor level in the ASIA motor examination?
- Hip flexors (iliopsoas)
- Knee extensors (quadriceps)
- Ankle dorsiflexors (tibialis anterior) (Correct answer)
- Long toe extensors (EHL)
Correct answer: Ankle dorsiflexors (tibialis anterior)
Ankle dorsiflexors (tibialis anterior) are the L4 key muscles per the ASIA standardized motor assessment.
NCS Spinal Cord Injury 2
According to the ASIA Impairment Scale, an ASIA A classification indicates: