MCOLES State Licensing Practice Exam

What type of nystagmus can be observed when a person is spinning around?

1. Resting Nystagmus

2. Optokinetic Nystagmus

3. Rotational Nystagmus

4. Horizontal Nystagmus

The correct answer is: Rotational Nystagmus

Rotational nystagmus is the type of nystagmus observed when a person is spinning around. This phenomenon occurs due to the effects of angular acceleration on the vestibular system. When someone spins, the fluid in the semicircular canals of the inner ear moves, causing the hair cells to bend and send signals to the brain about the motion. Once the spinning stops, the fluid continues to move for a brief period, which confuses the brain and can result in involuntary eye movements known as nystagmus, specifically characterized by a slow phase that follows the direction of spin and a quick phase that returns the eyes to the center. In contrast, resting nystagmus happens when the eyes move involuntarily even while the person is stationary, often associated with certain medical conditions affecting the vestibular system. Optokinetic nystagmus occurs in response to large, moving visual stimuli and is used in everyday situations, such as tracking objects in motion. Horizontal nystagmus refers specifically to eye movements that oscillate horizontally but does not encompass the specific response seen during rotational movements. These distinctions clarify why rotational nystagmus is the correct observation during spinning activities.