Which findings differentiate central vertigo from peripheral vertigo, and what initial steps should be taken?

• A. Peripheral vertigo shows vertical nystagmus and limb ataxia.
• B. Central vertigo shows horizontal nystagmus and a positive Dix-Hallpike.
• C. A mixed description.
• D. Central vertigo shows vertical nystagmus with limb ataxia; peripheral vertigo shows horizontal nystagmus and a positive Dix-Hallpike; ensure safety and treat nausea.

Answer: (D)

The main idea is telling central from peripheral vertigo by looking at eye movements and associated neurological signs, and starting with safety and symptom relief right away. Central vertigo tends to show vertical nystagmus (upbeat or downbeat) and can have limb ataxia or other brainstem/cerebellar signs, reflecting a central source. Peripheral vertigo usually presents with horizontal or rotary nystagmus that is often fatigable and without limb ataxia, and the Dix-Hallpike test is used to diagnose BPPV, a common peripheral cause.

In this scenario, vertical nystagmus with limb ataxia points to central vertigo, while peripheral vertigo would more likely involve horizontal nystagmus and a positive Dix-Hallpike indicating BPPV. For initial management, ensure safety to prevent falls and treat nausea; further evaluation should be guided by the presence of red flags or new focal neurologic deficits, which would warrant urgent imaging and specialist consultation.