Transient cerebral ischemic attacks and related syndromes (G45)
ICD-10 code group G45 covers transient cerebral ischemic attacks and related syndromes, which are brief episodes of reduced blood flow to the brain causing temporary neurological symptoms. These codes are used to classify conditions involving sudden but short-lived brain ischemia without permanent damage.
The detailed codes within the G45 section specify different types of transient ischemic events. For example, G45.0 represents vertebro-basilar artery syndrome, encompassing terms like vertebrobasilar artery syndrome and acute cerebral ischemia. G45.1 identifies carotid artery syndrome (hemispheric), also known as carotid territory transient ischemic attack. G45.3 relates to amaurosis fugax, a temporary vision loss often linked to carotid insufficiency. G45.4 captures transient global amnesia, which involves temporary loss of memory. Other codes like G45.8 cover less common syndromes such as subclavian steal syndrome. The unspecified code G45.9 is used when the transient ischemic attack type is not clearly documented. Medical coders rely on these to accurately classify and document transient cerebral ischemic events based on symptoms and affected arteries.
Diseases of the nervous system (G00–G99)
Episodic and paroxysmal disorders (G40-G47)
G45 Transient cerebral ischemic attacks and related syndromes
- G45.0 Vertebro-basilar artery syndrome
- G45.1 Carotid artery syndrome (hemispheric)
- G45.2 Multiple and bilateral precerebral artery syndromes
- G45.3 Amaurosis fugax
- G45.4 Transient global amnesia
- G45.8 Other transient cerebral ischemic attacks and related syndromes
- G45.9 Transient cerebral ischemic attack, unspecified
Transient cerebral ischemic attacks and related syndromes (G45)
Instructional Notations
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Clinical Terms
The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.
Amaurosis Fugax
Transient complete or partial monocular blindness due to retinal ischemia. This may be caused by emboli from the CAROTID ARTERY (usually in association with CAROTID STENOSIS) and other locations that enter the central RETINAL ARTERY. (From Adams et al., Principles of Neurology, 6th ed, p245)
Subclavian Steal Syndrome
A clinically significant reduction in blood supply to the BRAIN STEM and CEREBELLUM (i.e., VERTEBROBASILAR INSUFFICIENCY) resulting from reversal of blood flow through the VERTEBRAL ARTERY from occlusion or stenosis of the proximal subclavian or brachiocephalic artery. Common symptoms include VERTIGO; SYNCOPE; and INTERMITTENT CLAUDICATION of the involved upper extremity. Subclavian steal may also occur in asymptomatic individuals. (From J Cardiovasc Surg 1994;35(1):11-4; Acta Neurol Scand 1994;90(3):174-8)
