2024 ICD-10-CM Diagnosis Code G45.8

Other transient cerebral ischemic attacks and related syndromes

ICD-10-CM Code:
Short Description:
Oth transient cerebral ischemic attacks and related synd
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Code Navigator:

Code Classification

  • Diseases of the nervous system
    • Episodic and paroxysmal disorders
      • Transient cerebral ischemic attacks and related syndromes

G45.8 is a billable diagnosis code used to specify a medical diagnosis of other transient cerebral ischemic attacks and related syndromes. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acute cerebral ischemia
  • Acute cerebral ischemia
  • Acute cerebrovascular insufficiency
  • Acute cerebrovascular insufficiency
  • Arterial steal syndrome
  • Arterial steal syndrome
  • Arterial steal syndrome
  • Arterial steal syndrome
  • Carotid territory transient ischemic attack
  • Cerebral steal syndrome
  • Left subclavian steal syndrome
  • Right subclavian steal syndrome
  • Subclavian steal syndrome
  • Vertebrobasilar territory transient ischemic attack

Clinical Classification

Clinical Information

  • 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)
  • Subclavian Steal Syndrome

    an uncommon neurovascular condition seen with exertion of the upper extremity. it is usually caused by atherosclerotic stenosis or occlusion of the subclavian artery proximal to the origin of the vertebral artery. in order to maintain adequate perfusion of the arm during exercise on the affected side, the narrowed subclavian artery siphons off retrograde blood flow from the ipsilateral vertebral artery. this is possible due to lower blood pressure distal to the site of narrowing and collateral circulation through the circle of willis. affected individuals may remain asymptomatic until the oxygen demand generated from upper extremity exercise requires a large enough compensatory volume of blood to be diverted from the vertebral artery to provoke vertebrobasilar insufficiency and its accompanying neurological sequelae. presenting clinical signs may include pain or numbness of the affected arm (with diminished pulses and a brachial systolic blood pressure differential of greater than 20 mmhg as compared to the opposite arm), vertigo, tinnitus, dysarthria, diplopia and syncope. notably, unlike cerebral infarction, the clinical course does not lead to chronic neurologic disability. prognosis for recovery of normal anterograde circulation is favorable following endovascular or surgical intervention.

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert G45.8 to ICD-9-CM

  • ICD-9-CM Code: 435.2 - Subclavian steal syndrom
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.
  • ICD-9-CM Code: 435.8 - Trans cereb ischemia NEC
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education

Transient Ischemic Attack

A transient ischemic attack (TIA) is a stroke that lasts only a few minutes. It happens when the blood supply to part of the brain is briefly blocked. Symptoms of a TIA are like other stroke symptoms, but do not last as long. They happen suddenly, and include:

  • Numbness or weakness, especially on one side of the body
  • Confusion or trouble speaking or understanding speech
  • Trouble seeing in one or both eyes
  • Difficulty walking
  • Dizziness
  • Loss of balance or coordination

Most symptoms of a TIA disappear within an hour, although they may last for up to 24 hours. Because you cannot tell if these symptoms are from a TIA or a stroke, you should go to the hospital right away.

TIAs are often a warning sign for future strokes. Taking medicine, such as blood thinners, may reduce your risk of a stroke. Your doctor might also recommend surgery. You can also help lower your risk by having a healthy lifestyle. This includes not smoking, not drinking too much, eating a healthy diet, and exercising. It is also important to control other health problems, such as high blood pressure and cholesterol.

NIH: National Institute of Neurological Disorders and Stroke

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.