Which sign is most consistent with a peripheral vestibular lesion?

• A. Spontaneous nystagmus that persists with fixation
• B. Direction-changing nystagmus with gaze
• C. Unidirectional, fatigable nystagmus with no skew deviation
• D. Bilateral symmetric caloric response

Answer: (C)

A peripheral vestibular lesion tends to produce a nystagmus that is unidirectional, fatigable, and without skew deviation. When one labyrinth is affected, the eye movement pattern beats in a single direction toward the healthy ear; this nystagmus often fatigues over time as the system adapts. The absence of a skew deviation means there isn’t a vertical misalignment pointing to brainstem or central involvement. In contrast, central patterns often show direction-changing nystagmus with gaze or spontaneous nystagmus that persists with fixation, and bilateral symmetric caloric responses suggest bilateral or central issues rather than a unilateral peripheral problem. So the described unidirectional, fatigable nystagmus with no skew deviation best fits a peripheral lesion.