A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
An 82-year-old male visits his primary care physician for a check-up. He reports that he is in his usual state of health. His only new complaint is that he feels as if the room is spinning, which has affected his ability to live independently. He is currently on lisinopril, metformin, aspirin, warfarin, metoprolol, and simvastatin and says that he has been taking them as prescribed. On presentation, his temperature is 98.8°F (37°C), blood pressure is 150/93 mmHg, pulse is 82/min, and respirations are 12/min. On exam he has a left facial droop and his speech is slightly garbled. Eye exam reveals nystagmus with certain characteristics. The type of nystagmus seen in this patient would most likely also be seen in which of the following diseases?
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A
Aminoglycoside toxicityIncorrect. Aminoglycoside toxicity damages vestibular hair cells, producing peripheral nystagmus that suppresses with fixation — different from the central pattern of a brainstem stroke.
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B
Benign paroxysmal positional vertigoIncorrect. BPPV produces brief positional rotary nystagmus that fatigues with repetition — a peripheral pattern.
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C
Meniere diseaseIncorrect. Meniere disease causes peripheral nystagmus with episodic vertigo, hearing loss, and tinnitus.
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D
Multiple sclerosisCorrect. MS produces central nystagmus (often with INO) from brainstem demyelination, the same central pattern as in this patient's brainstem stroke.
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E
Vestibular neuritisIncorrect. Vestibular neuritis causes acute unidirectional peripheral nystagmus that suppresses with fixation, unlike the central nystagmus pattern of this patient's brainstem stroke.
↑ Tap an answer to reveal the reasoning
Answer: D. An 82-year-old on warfarin with facial droop, garbled speech, vertigo, and nystagmus has an acute stroke. Central (brainstem/cerebellar) causes of vertigo produce a vertical or pure-torsional nystagmus that does not suppress with visual fixation and may change direction with gaze. Among the answer choices, multiple sclerosis is the prototypical central cause that produces internuclear ophthalmoplegia (impaired adduction of the ipsilateral eye with nystagmus of the abducting contralateral eye) and other central nystagmus patterns.
Peripheral causes (BPPV, vestibular neuritis, Meniere's, aminoglycoside ototoxicity) produce horizontal/rotary nystagmus that fatigues, suppresses with fixation, and is unidirectional. The patient's brainstem stroke with focal neurologic deficits indicates a central process, so the matching pathology among the choices is MS, which also causes central nystagmus from brainstem demyelination.
Key clue: peripheral nystagmus suppresses with fixation; central nystagmus does not. Vertical or direction-changing nystagmus is essentially always central.
**Why each option:**
**A.** Aminoglycoside toxicity damages vestibular hair cells, producing peripheral nystagmus that suppresses with fixation — different from the central pattern of a brainstem stroke.
**B.** BPPV produces brief positional rotary nystagmus that fatigues with repetition — a peripheral pattern.
**C.** Meniere disease causes peripheral nystagmus with episodic vertigo, hearing loss, and tinnitus.
**D.** Correct — MS produces central nystagmus (often with INO) from brainstem demyelination, the same central pattern as in this patient's brainstem stroke.