Critical Vertebrobasilar Insufficiency From Left Intracranial Vertebral Artery Stenosis With Contralateral Hypoplasia Presenting as Recurring Vertigo: Urgent Stenting to Prevent the Progression of a Posterior Circulation Stroke.

A 67-year-old man with a history of hypertension and untreated dyslipidemia presented with a four-day history of frequent episodic vertigo associated with nausea and vomiting. The patient experienced up to 20 episodes of spinning vertigo per day, each lasting several minutes, without provocation by head movement. MRI confirmed acute infarcts in the right posterior cerebral and cerebellar territories, and CTA revealed severe stenosis of the left vertebral artery V4 segment, with a hypoplastic right vertebral artery. Given refractory symptoms despite dual antiplatelet therapy and permissive hypertension, urgent intracranial balloon angioplasty and balloon-mounted drug-eluting stent placement was performed. The patient recovered completely without further dizziness or neurological deficit. This case emphasizes that recurrent atypical vertigo and brief syncope may be warning signs of vertebrobasilar insufficiency, especially in the context of vertebral artery stenosis with limited collateral flow. Timely vascular imaging and intervention can prevent subsequent debilitating brainstem stroke.