Contrast-induced encephalopathy (CIE)

David Goldemund M.D.
Updated on 05/01/2024, published on 08/12/2021

  • contrast-induced encephalopathy (CIE) is a rare neurological complication that occurs during or after the use of a contrast media in various angiographic procedures
    • such as coronary angiography, diagnostic cerebral DSA, carotid angioplasty, and EVT in acute stroke patients    (Chu, 2020)
    • it has been reported with the use of different contrast agents, but the hyperosmolar ones pose a higher risk (up to 4%)
  • transient symptoms
  • incidence 0.1-3%    (Chu, 2020)
  • generally good prognosis, spontaneous resolution of symptoms occurs within minutes to a few days

Etiopathogenesis of contrast-induced encephalopathy

  • CIE is provoked by intraarterial administration of an iodinated contrast agent
    • not reported after intravenous administration
  • the exact mechanism is not clear; probably a combination of blood-brain barrier (BBB) disruption and direct neurotoxicity from the contrast agent results in altered neuronal excitability and dysfunction   (Leong, 2012) (Yu, 2011)
    • the occipital lobes have increased BBB permeability; therefore, changes are most common here [Muruve, 1996]
  • predisposing factors:
    • hypertension
    • nephropathy with reduced contrast agent clearance
    • impaired cerebral autoregulation
    • large amount of contrast agent (usually > 100 mL)
    • application into the vertebrobasilar territory (selective DSA)
    • history of stroke (the previous stroke may disrupt the BBB in the same or adjacent vascular territory, facilitating contrast leakage and causing tissue reaction and cerebral edema)

Clinical presentation

  • development during the endovascular procedure or within hours following intraarterial contrast administration
  • may cause the following focal symptoms or encephalopathy:
  • CIE should be suspected in acute stroke patients who exhibit clinical deterioration, contrast enhancement, and edematous changes on imaging after EVT (particularly in patients with renal impairment or a history of stroke)
  • resolution typically occurs within 24 hours to a few days

Diagnostic evaluation

  • NCCT+CTA/MRI+MRA are used to rule out thromboembolism or bleeding (especially after EVT in acute stroke patients)
  • NCCT
    • normal
    • cortical or subcortical enhancement due to contrast leakage
    • vasogenic edema with potential mass effect
  • dual-energy CT may help to differentiate contrast enhancement from hemorrhage
  • MRI shows cortical hyperintensities on T2, FLAIR, and DWI, but ADC is negative! (differentiation from ischemia)
  • GRE or SWI can differentiate subtle hemorrhage from contrast enhancement

Differential diagnosis


  • hydrate with crystalloids
  • provide symptomatic treatment (e.g., antiseizure medication, anxiety control, blood pressure control)
  • the use of corticosteroids may have a probable effect  [Chisci, 2011]


  • complete recovery usually occurs within a few days
  • permanent neurological deficits are rare

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Contrast-induced encephalopathy (CIE)