Which type of nystagmus occurs due to fluid motion in the vestibular system?

Caloric nystagmus is a specific type of nystagmus that occurs when there is fluid motion in the vestibular system, particularly due to temperature changes in the inner ear. When warm or cold fluid is introduced into the ear, it causes a differential in temperature, which in turn affects the vestibular system. This leads to changes in the signals sent to the brain regarding balance and spatial orientation. When the vestibular system detects this change, it can trigger involuntary eye movements, which is the nystagmus observed.

This phenomenon is often tested in clinical settings to evaluate the function of the vestibular system. The responses can indicate whether there is a normal functioning of the vestibular pathways. Understanding caloric nystagmus is crucial for diagnoses related to balance disorders and other issues associated with inner ear function.

In contrast, other forms of nystagmus listed in the options arise from different mechanisms. For example, positional alcohol nystagmus is related to the effects of alcohol on the inner ear, which does not directly involve the kind of fluid motion associated with caloric nystagmus. Similarly, rotational nystagmus is linked to spinning movements rather than temperature-induced fluid motion, while repetitive nystag