Which sign is described as rhythmic, quick, oscillatory movements of the eyes?

• A. Inability to perform rapid alternating movements
• B. Movement decomposition
• C. Rhythmic, quick oscillatory eye movements
• D. Broad base of support during gait

Answer: (C)

Rhythmic, quick oscillatory eye movements describe nystagmus. It’s an involuntary eye movement pattern where the eyes drift slowly in one direction and then rapidly snap back with a quick corrective movement. Nystagmus can be horizontal, vertical, or rotary and points to disturbances in vestibulo-ocular pathways or in cerebellar/brainstem circuits. While it can be normal in certain situations, on exam it indicates a dysfunction of the vestibular system or central ocular motor control. In contrast, the other signs refer to different motor issues: difficulty with rapid alternating movements signals dysdiadochokinesia, movement decomposition describes breaking a movement into parts rather than a smooth sequence, and a broad base of support during gait indicates an ataxic gait.