I63.213

HCC Category Mapping

What This Code Means

A stroke caused by a blockage or narrowing of both vertebral arteries (major blood vessels in the neck that supply the back of the brain), where the exact cause of the blockage is not specified. This condition restricts blood flow to the brain and can result in permanent brain damage.

Coding Tips

• •This code requires documentation confirming bilateral (both sides) vertebral artery involvement; if only one side is affected, use a different code such as I63.211 or I63.212
• •The 'unspecified occlusion or stenosis' component means the documentation does not specify whether it's a complete blockage (occlusion) or partial narrowing (stenosis); if the type is documented, use a more specific code from the I63.21- subcategory

Clinical Significance

Cerebral infarction due to unspecified occlusion or stenosis of bilateral vertebral arteries is a rare and serious posterior circulation stroke where both vertebral arteries are compromised. Bilateral vertebral artery occlusion can lead to basilar artery insufficiency and brain stem ischemia. The unspecified mechanism component means documentation does not clarify whether the cause is thrombosis, embolism, or progressive stenosis.

Documentation Requirements

• ✓Imaging confirmation of posterior circulation cerebral infarction
• ✓Vascular imaging confirming bilateral vertebral artery occlusion or stenosis
• ✓Documentation explicitly stating bilateral involvement
• ✓Comprehensive neurological examination with brain stem and posterior circulation assessment
• ✓Evaluation for underlying causes (atherosclerosis, hypercoagulability, dissection)
• ✓Treatment documentation and prognosis

Commonly Confused Codes