NIHSS Limb Ataxia 2 — Questions and Answers
Question 1: A patient with a right-hemisphere stroke can extend both arms but shows marked tremor and dysmetria only in the left arm. How is limb ataxia scored?
- 0 — no ataxia present
- 1 — ataxia in one limb (Correct answer)
- 2 — ataxia in two limbs
- 3 — ataxia in all four limbs
Correct answer: 1 — ataxia in one limb
Ataxia is present in one limb (left arm), so the score is 1.
Question 2: Which cerebellar pathway is most commonly implicated when limb ataxia is detected on the NIHSS after an acute ischemic stroke?
- Corticospinal tract
- Spinocerebellar tract via the posterior inferior cerebellar artery territory (Correct answer)
- Dorsal column–medial lemniscus pathway
- Reticulospinal tract
Correct answer: Spinocerebellar tract via the posterior inferior cerebellar artery territory
The posterior inferior cerebellar artery (PICA) territory supplies the spinocerebellar pathways, and infarcts there frequently cause limb ataxia.
Question 3: An examiner asks a hemiplegic patient to perform heel-to-shin testing on the paretic leg. The patient cannot lift the leg at all. What is the correct score?
- 0
- 1
- 2
- UN — untestable (Correct answer)
Correct answer: UN — untestable
When weakness prevents performance of the task, the item is scored UN (untestable) and ataxia cannot be attributed.
Question 4: Limb ataxia on the NIHSS is specifically designed to detect dysfunction of which neural structure?
- Basal ganglia
- Cerebellum and its pathways (Correct answer)
- Thalamus
- Primary motor cortex
Correct answer: Cerebellum and its pathways
The limb ataxia item isolates cerebellar dysfunction by testing coordination independent of weakness.
Question 5: A stroke patient scores 2 on the limb ataxia item. What does this indicate?
- Mild ataxia in one limb
- Ataxia present in one limb only
- Ataxia present in two limbs (Correct answer)
- Severe ataxia preventing any limb movement
Correct answer: Ataxia present in two limbs
A score of 2 on the NIHSS limb ataxia item means ataxia is present in two limbs.
Question 6: During finger-nose-finger testing, a patient overshoots the target repeatedly but has full strength (5/5). Which term best describes this finding?
- Dysmetria (Correct answer)
- Dysdiadochokinesia
- Astereognosis
- Allodynia
Correct answer: Dysmetria
Dysmetria is the inability to judge distance or scale of movement, causing overshooting or undershooting of the target.
Question 7: A patient has a score of 0 on the NIHSS limb ataxia item. What can the clinician conclude?
- The patient has no cerebellar lesion
- No ataxia was detected during testing (Correct answer)
- Limb coordination is permanently intact
- The patient passed all motor strength tests
Correct answer: No ataxia was detected during testing
A score of 0 means no ataxia was observed during the examination; it does not rule out all cerebellar pathology.
NIHSS Limb Ataxia 2
A patient with a right-hemisphere stroke can extend both arms but shows marked tremor and dysmetria only in the left arm.
How is limb ataxia scored?