NIHSS Limb Ataxia 3 — Questions and Answers
Question 1: A patient with a left PICA infarct demonstrates ataxia in both the left arm and left leg during NIHSS testing. How should the limb ataxia item be scored?
- 0
- 1
- 2 (Correct answer)
- 3
Correct answer: 2
Ataxia in two limbs (ipsilateral arm and leg) yields a score of 2.
Question 2: Why does the NIHSS instruct examiners to score limb ataxia only in proportion to weakness?
- To avoid underscoring in hemiplegic patients
- Because weakness alone can mimic ataxia and must be distinguished (Correct answer)
- To increase the sensitivity of the scale for cortical strokes
- Because ataxia and weakness always co-occur
Correct answer: Because weakness alone can mimic ataxia and must be distinguished
Weakness can prevent smooth movement and falsely appear as ataxia, so the NIHSS requires that coordination deficits be out of proportion to motor deficits to count.
Question 3: Which test is used to evaluate lower-limb ataxia in a supine stroke patient during NIHSS assessment?
- Romberg test
- Heel-to-shin test (Correct answer)
- Tandem gait
- Heel-to-toe walking
Correct answer: Heel-to-shin test
The heel-to-shin test is the standard NIHSS maneuver for assessing lower-limb coordination in bed-bound patients.
Question 4: A patient with a brainstem stroke has bilateral upper-limb ataxia but intact lower-limb coordination. What is the limb ataxia score?
- 0
- 1
- 2 (Correct answer)
- 4
Correct answer: 2
Both upper limbs are ataxic (two limbs total), yielding a score of 2.
Question 5: An aphasic patient cannot follow verbal commands for finger-nose-finger testing. The examiner uses a visual demonstration. The patient still cannot perform the task due to apparent confusion. How is limb ataxia recorded?
- 0 — assume intact
- 1 — partial credit
- 2 — full score
- UN — untestable (Correct answer)
Correct answer: UN — untestable
If ataxia cannot be assessed due to cognitive or communication barriers preventing task performance, the item is scored UN.
Question 6: Which clinical scenario would most likely produce a limb ataxia score of 0 on NIHSS despite a cerebellar infarct?
- Large hemispheric cerebellar stroke with profound dysmetria
- Small cerebellar infarct with no observable coordination deficit at bedside (Correct answer)
- Bilateral PICA territory infarcts
- Anterior inferior cerebellar artery (AICA) infarct with bilateral arm ataxia
Correct answer: Small cerebellar infarct with no observable coordination deficit at bedside
A small cerebellar infarct may produce no detectable coordination deficit on bedside testing, resulting in a score of 0.
Question 7: When scoring limb ataxia in a patient with severe hemiplegia (grade 0/5 in arm and leg on one side), which approach is correct?
- Score the ataxia as present because the limbs cannot move
- Score ataxia as 0 because paralyzed limbs cannot demonstrate ataxia
- Score as 2 because both limbs on one side are affected
- Score as UN for the paralyzed side and test only the intact side (Correct answer)
Correct answer: Score as UN for the paralyzed side and test only the intact side
Completely paralyzed limbs are designated untestable (UN) for ataxia; only limbs with sufficient strength to perform the task can be scored.
NIHSS Limb Ataxia 3
A patient with a left PICA infarct demonstrates ataxia in both the left arm and left leg during NIHSS testing.
How should the limb ataxia item be scored?