Occlusion and stenosis of basilar artery

This code identifies a narrowing or complete blockage of the basilar artery, a critical blood vessel at the base of the brain that supplies oxygenated blood to the brainstem, cerebellum, and posterior cerebrum. This condition can lead to severe neurological deficits due to compromised blood flow to these vital areas.

Assign this code when documentation explicitly states occlusion or stenosis of the basilar artery, often identified through imaging studies such as MRA, CTA, or conventional angiography. It is typically used in patients presenting with symptoms of vertebrobasilar insufficiency, such as vertigo, ataxia, diplopia, or sudden neurological deficits.

• Distinguish between acute and chronic occlusion/stenosis if specified in the documentation, as this code does not differentiate.
• Always code any associated neurological deficits or sequelae (e.g., stroke, transient ischemic attack) separately.
• Ensure the documentation clearly specifies the basilar artery; do not use for other intracranial or extracranial arterial occlusions/stenoses.