Elsevier

World Neurosurgery

Volume 126, June 2019, Pages 341-345
World Neurosurgery

Case Report
Arterial Spin Labeling Magnetic Resonance Imaging to Diagnose Contrast-Induced Vasospasm After Intracranial Stent Embolization

https://doi.org/10.1016/j.wneu.2019.03.069Get rights and content

Background

Contrast-induced encephalopathy (CIE) is a rare and misdiagnosed complication of intravascular injection of contrast, responsible for arterial vasospasm and neurologic effects. Conventional radiologic findings are not in themselves specific for cerebral vasospasm diagnosis. We present a case in which arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) was useful in early diagnosis of CIE.

Case Description

A 56-year-old woman was admitted for elective flow-diverter embolization of a recanalized left supra-ophthalmic internal carotid artery aneurysm; at 4 hours postprocedure, she acutely developed sensitive aphasia and right arm paresis. Although no-contrast computed tomography and MRI with fluid-attenuated inversion recovery and diffusion-weighted imaging sequences did not demonstrate acute ischemic/hemorrhagic cerebral foci or cortical edema, ASL showed decreased cerebral blood flow (CBF) in the insular-temporal-parietal anterior lobe, suspected for hypoperfusion due to vasospasm, which was not confirmed by subsequent emergent digital subtraction angiography. At 16 hours, because of worsening symptoms, patient underwent an additional MRI, which showed slight insular cortical edema on fluid-attenuated inversion recovery and corresponding slight restricted diffusion-weighted imaging with a severe reduction in CBF value; at this time, emergent digital subtraction angiography demonstrated distal arterial vasospasm of left middle cerebral artery, and vasospasm therapy was started. Within 48 hours of symptom onset, the patient gradually improved to a complete neurologic recovery, with normalization of CBF values in the concerning cerebral region.

Conclusions

CIE should always be considered in patients with focal neurologic deficits after iodinate contrast exposure. ASL perfusion MRI with CBF maps could be a promising tool for prompt, early confirmation of underlying vasospasm, as cortical edema and distal vasospasm could not be detected on conventional radiologic imaging.

Introduction

Contrast-induced encephalopathy (CIE), also known as iodinated contrast encephalopathy, is a rare and misdiagnosed complication of intravascular injection of iodinated contrast.1, 2 Neurotoxicity from iodinated contrast agents leads to neurologic deficits, which may mimic acute stroke or transient ischemic attack. Although the underlying mechanism of injury is not well understood, it has been postulated that a combination of chemotoxic effects from contrast hyperosmolarity together with direct neurotoxicity of the contrast agent itself are responsible for arterial vasospasm, cortical edema, and neurologic effects.3, 4 Patients usually develop neurologic symptoms shortly after the exposure (2–12 hours), which vary according to the part of the brain affected (encephalopathy, convulsions, cortical blindness, and focal neurologic deficits).5, 6

Imaging is essential in confirming the diagnosis and in excluding thromboembolic and hemorrhagic complications after iodinated contrast exposure. The typical noncontrast computed tomography (CT) findings are hyperdensity of the cerebral sulci similar to subarachnoid hemorrhage and subcortical edema. On magnetic resonance imaging (MRI), hyperintense foci can be seen on fluid-attenuated inversion recovery (FLAIR) T2-weighted sequences and diffusion-weighted imaging (DWI), depending on time of onset.7, 8, 9

For the first time in literature, we report a case of acute CIE after flow-diverter stenting embolization of a recanalized intracranial aneurysm, in which only the additional use of arterial spin labeling (ASL) perfusion sequences allowed early diagnosis of distal intracranial arterial vasospasm with no signs of cortical edema in conventional CT and MRI and no vasospasm in digital subtraction angiography (DSA).

Section snippets

Case Report

A 56-year-old woman with a history of hypertension and endovascular coil embolization of a 5-mm ruptured right supra-ophthalmic internal carotid artery aneurysm 6 months previously underwent a follow-up angiography, which demonstrated a recanalization of the treated aneurysm, with a 3-mm neck. The patient underwent elective flow-diverter (Pipeline 3.75−18 mm) embolization (Medtronic, Minneapolis, Minnesota, USA) of the recanalized supra-ophthalmic internal carotid artery aneurysm, with no

Discussion

Although most patients with CIE fully recover within 72 hours, a minority (approximately 15%) have persistent neurologic deficit or die of cerebral edema.2 For this reason, the condition should be early recognized to avoid potential harmful effect.

In our case, CIE was related to cerebral angiography in which a flow-diverter stent was positioned in a recanalized supra-ophthalmic aneurysm. The patient gradually developed global aphasia, right hemiparesis, left look deviation, and VII cranial

Conclusions

CIE is a rare complication of endovascular treatment for cerebrovascular diseases and always should be considered in patients with focal neurologic deficits after contrast exposure. ASL perfusion MRI with CBF maps could be a promising tool for prompt and early diagnosis of hypoperfusion due to vasospasm in CIE, when conventional CT/MRI and DSA still do not demonstrate cortical edema and distal vasospasm, respectively.

References (17)

  • M. Fischer-Williams et al.

    Transient cortical blindness. An unusual complication of coronary angiography

    Neurology

    (1970)
  • S. Leong et al.

    Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature

    Interv Neuroradiol

    (2012)
  • E.C. Haley

    Encephalopathy following arteriography: a possible toxic effect of contrast agents

    Ann Neurol

    (1984)
  • J. Yu et al.

    New insights into the risk factors of contrast-induced encephalopathy

    J Endovasc Ther

    (2011)
  • A. Torvik et al.

    Neurotoxicity of water-soluble contrast media

    Acta Radiol

    (1995)
  • B.N. Alp et al.

    Transient cortical blindness after coronary angiography

    J Int Med Res

    (2009)
  • L. Guimaraens et al.

    Transient encephalopathy from angiographic contrast: a rare complication in neurointerventional procedures

    Cardiovasc Intervent Radiol

    (2010)
  • G. Lantos

    Cortical blindness due to osmotic disruption of the blood-brain barrier by angiographic contrast material: CT and MRI studies

    Neurology

    (1989)
There are more references available in the full text version of this article.

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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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