Cerebral infrc due to unsp occls or stenosis of precerb art

This diagnosis code signifies a cerebral infarction (ischemic stroke) resulting from a blockage or narrowing in a precerebral artery other than the carotid or vertebral arteries, where the specific type of occlusion or stenosis is not documented. It indicates brain tissue death caused by insufficient blood flow due to an unspecified obstruction in an extracranial artery supplying the brain.

Use this code when documentation confirms an ischemic stroke due to occlusion or stenosis of a precerebral artery (e.g., subclavian, innominate) but does not specify the nature of the occlusion (e.g., thrombosis, embolism, atherosclerosis). This code is appropriate when the physician's notes clearly state "cerebral infarction due to unspecified occlusion of other precerebral artery" or similar.

• Ensure the documentation specifies "unspecified" occlusion/stenosis and "other" precerebral arteries to differentiate from carotid or vertebral involvement.
• Do not use if the specific type of occlusion (e.g., thrombosis, embolism) is known; instead, use a more specific code from the I63.0-I63.4 series.
• Always sequence this code after any acute stroke codes (I60-I62) if applicable, or as the primary diagnosis if it's the reason for the encounter.