Middle cerebral artery syndrome

This code describes the neurological deficits resulting from an ischemic stroke or other vascular compromise affecting the middle cerebral artery (MCA) territory. These deficits typically include contralateral hemiparesis, hemisensory loss, and often aphasia (if the dominant hemisphere is affected) or neglect (if the non-dominant hemisphere is affected). It represents the clinical manifestation of MCA occlusion or stenosis.

Use this code when documentation clearly indicates a diagnosis of middle cerebral artery syndrome, often following an acute ischemic event. Supporting documentation should detail the specific neurological deficits localized to the MCA distribution, such as right-sided weakness and expressive aphasia due to a left MCA stroke. This code is appropriate for both acute and chronic phases of the syndrome.

• Ensure documentation specifies "syndrome" or clearly links the neurological deficits to the middle cerebral artery.
• Do not confuse with codes for specific types of stroke (e.g., I63.x for cerebral infarction) unless the syndrome is explicitly diagnosed.
• Sequence this code after the underlying cause (e.g., cerebral infarction, embolism) if known and still active, or as a primary diagnosis for the long-term sequelae.