Which condition presents with vertigo, diplopia, nystagmus, and ataxia and may include a drop attack due to transient cessation of blood flow?

• A. Posterior circulation
• B. Carotid artery TIA
• C. Transitional global amnesia
• D. Basilar artery TIA

Answer: (D)

When symptoms point to brainstem and cerebellar involvement, it suggests a posterior circulation issue. Vertigo, diplopia, nystagmus, and ataxia arise from disruption of vestibular pathways, cranial nerve circuits, and cerebellar connections that the basilar artery supplies. A transient ischemic attack in the basilar artery territory can briefly impair these brainstem regions, producing this cluster of signs. The drop attack—a sudden fall with little warning or loss of postural tone—fits basilar artery ischemia because the brainstem controls many aspects of tone and posture; transient hypoperfusion can cause a rapid, brief loss of balance leading to a fall without lasting weakness.

In contrast, carotid artery TIAs usually produce cortical signs like unilateral weakness or numbness, aphasia, or monocular vision loss, not a combination of brainstem and cerebellar symptoms. Transitional global amnesia presents mainly with sudden-onset amnesia and lacks these focal brainstem signs. So the presentation most consistent with basilar artery TIA is the one described.