Central Acute Vestibular Syndrome Due to Posterior Fossa Hemorrhage

This is a patient presenting with the acute vestibular syndrome (AVS, e.g., acute prolonged vertigo, spontaneous nystagmus) whose HINTS (Head Impulse, Nystagmus, Test of Skew) testing indicated a central etiology based on negative (normal) head impulse testing (HIT). Nystagmus was unidirectional and there was no skew deviation, which are both suggestive of a peripheral etiology. However, if any of the 3 ocular motor/vestibular tests suggest a central localization, the etiology must be assumed to be central until proven otherwise. The HIT is highly suggestive of a central etiology in the AVS when negative, whereas a + HIT can be seen occasionally with central as well as with peripheral etiologies. In his case, a right middle cerebellar peduncle hemorrhage was seen on MRI.