OSCE Neurological Assessment 5 — Questions and Answers
Question 1: A patient presents with loss of pain and temperature on the left side of the body and loss of proprioception and vibration on the right side. This crossed sensory pattern is called:
- Brown-Séquard syndrome (Correct answer)
- Central cord syndrome
- Anterior cord syndrome
- Conus medullaris syndrome
Correct answer: Brown-Séquard syndrome
Brown-Séquard syndrome results from hemisection of the spinal cord, causing ipsilateral proprioception loss (posterior column) and contralateral pain/temperature loss (spinothalamic tract).
Question 2: When assessing the abducens nerve (CN VI), which specific eye movement deficit would you expect with a complete palsy?
- Inability to adduct the ipsilateral eye
- Inability to abduct the ipsilateral eye (lateral gaze palsy) (Correct answer)
- Vertical gaze palsy
- Loss of pupillary constriction
Correct answer: Inability to abduct the ipsilateral eye (lateral gaze palsy)
CN VI innervates the lateral rectus muscle; a complete CN VI palsy causes inability to abduct the affected eye, resulting in esotropia (medial deviation) and diplopia on lateral gaze.
Question 3: A 78-year-old patient scores 24/30 on the MMSE. Which interpretation is most accurate?
- Severe cognitive impairment
- Moderate cognitive impairment
- Score in the normal range, no cognitive impairment likely (Correct answer)
- Mild cognitive impairment requiring specialist referral
Correct answer: Score in the normal range, no cognitive impairment likely
An MMSE score of 24-30 is generally considered within the normal range for cognitive function; scores below 24 raise concern for cognitive impairment.
Question 4: During facial nerve (CN VII) examination, you notice the patient cannot close the right eye, has drooping of the right corner of the mouth, and cannot raise the right eyebrow. This pattern indicates:
- Left upper motor neuron lesion
- Right upper motor neuron lesion
- Right lower motor neuron (peripheral) lesion (Correct answer)
- Left lower motor neuron lesion
Correct answer: Right lower motor neuron (peripheral) lesion
Lower motor neuron CN VII lesion causes complete ipsilateral facial weakness affecting both upper and lower face, including forehead; upper motor neuron lesions spare the forehead due to bilateral cortical representation.
Question 5: To assess for an upper motor neuron lesion in the leg, which sign would support this finding?
- Decreased or absent knee jerk reflex
- Positive Babinski sign (upgoing plantar response) (Correct answer)
- Fasciculations in the quadriceps
- Flaccid tone in the lower limb
Correct answer: Positive Babinski sign (upgoing plantar response)
The Babinski sign (upgoing great toe with fanning of other toes on plantar stimulation) indicates an UMN lesion causing disinhibition of primitive reflexes; absent reflexes and flaccidity suggest LMN lesions.
Question 6: A patient complains of double vision that is worse when looking to the right. On examination, the left eye fails to adduct on rightward gaze, but convergence is intact. This is most consistent with:
- Left CN VI palsy
- Right CN III palsy
- Left internuclear ophthalmoplegia (INO) (Correct answer)
- Bilateral CN VI palsy
Correct answer: Left internuclear ophthalmoplegia (INO)
Internuclear ophthalmoplegia causes failure of adduction of the ipsilateral eye on lateral gaze due to a medial longitudinal fasciculus (MLF) lesion, with preserved convergence.
Question 7: When assessing sensation, a patient can feel light touch but reports that a tuning fork (128 Hz) feels identical on both sides of a bony prominence. What does this indicate?
- Normal vibration sense bilaterally
- Loss of vibration sense requiring posterior column investigation (Correct answer)
- Hyperesthesia suggesting peripheral nerve irritation
- Intact proprioceptive pathways
Correct answer: Loss of vibration sense requiring posterior column investigation
A patient should perceive vibration clearly on bony prominences; if the sensation is the same on both sides when one side is expected to be dampened, it suggests impaired vibration sense and posterior column dysfunction.
OSCE Neurological Assessment 5
A patient presents with loss of pain and temperature on the left side of the body and loss of proprioception and vibration on the right side.
This crossed sensory pattern is called: