OSCE Neurological Assessment 3 — Questions and Answers
Question 1: When testing the corneal reflex, the afferent limb is carried by which nerve?
- CN VII (facial nerve)
- CN V1 (ophthalmic branch of trigeminal) (Correct answer)
- CN III (oculomotor nerve)
- CN VI (abducens nerve)
Correct answer: CN V1 (ophthalmic branch of trigeminal)
The afferent limb of the corneal reflex travels via CN V1 (ophthalmic division of trigeminal), while the efferent blink response is mediated by CN VII.
Question 2: A 65-year-old has right-sided facial droop affecting both upper and lower face, right arm weakness, and right leg weakness. Where is the lesion?
- Right internal capsule
- Left internal capsule (Correct answer)
- Right facial nerve nucleus
- Left corticobulbar tract only
Correct answer: Left internal capsule
Left internal capsule lesion causes contralateral (right-sided) hemiplegia including lower face, arm, and leg due to interruption of corticospinal and corticobulbar fibers.
Question 3: Which maneuver is used to assess for meningeal irritation by passively flexing the hip and knee then extending the knee?
- Brudzinski's sign
- Kernig's sign (Correct answer)
- Lhermitte's sign
- Spurling's test
Correct answer: Kernig's sign
Kernig's sign is positive when extension of the knee from a flexed hip position produces pain or resistance, indicating meningeal irritation.
Question 4: A patient with a suspected stroke has sudden loss of the right visual field in both eyes. The lesion most likely involves:
- Right optic nerve
- Optic chiasm
- Left optic tract or left occipital cortex (Correct answer)
- Right occipital cortex
Correct answer: Left optic tract or left occipital cortex
Right homonymous hemianopia (loss of the right visual field in both eyes) results from a lesion in the left optic tract, left lateral geniculate body, or left occipital cortex.
Question 5: When performing the finger-nose-finger test, a patient's finger overshoots the target and the error worsens as the finger approaches. This is best described as:
- Tremor at rest
- Intention tremor with dysmetria (Correct answer)
- Asterixis
- Myoclonus
Correct answer: Intention tremor with dysmetria
Dysmetria (overshoot/undershoot) and intention tremor that worsens on approach to the target are hallmarks of cerebellar dysfunction assessed by the finger-nose-finger test.
Question 6: Which reflex level corresponds to testing the ankle jerk (Achilles reflex)?
- L2-L3
- L3-L4
- L4-L5
- S1-S2 (Correct answer)
Correct answer: S1-S2
The ankle jerk reflex arc travels through the S1-S2 nerve roots; absence suggests S1 radiculopathy or peripheral neuropathy affecting these levels.
Question 7: A patient cannot identify which finger the examiner is touching with eyes closed. This cortical sensory deficit is called:
- Anosognosia
- Finger agnosia (Correct answer)
- Tactile extinction
- Two-point discrimination loss
Correct answer: Finger agnosia
Finger agnosia, the inability to identify individual fingers when touched, is a sign of parietal lobe dysfunction, often associated with Gerstmann syndrome.
OSCE Neurological Assessment 3
When testing the corneal reflex, the afferent limb is carried by which nerve?