Vestibular First on Instagram: "Seeing right-beating nystagmus after head shake? Here’s what it tells us! The head shake test is a valuable bedside screening tool to detect subtle vestibular asymmetries that may not be apparent during a basic oculomotor exam. In a normally functioning vestibular system, symmetric input from both sides cancels out any nystagmus. However, when one vestibular system is not working as well as the other, the asymmetry in neural firing leads to a temporary imbalance,