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Contrast-induced encephalopathy mimicking subarachnoid hemorrhage in the intensive care unit

Contrast-induced encephalopathy

Article information

J Neurocrit Care. 2025;17(1):39-40
Publication date (electronic) : 2025 June 26
doi : https://doi.org/10.18700/jnc.250013
Maria Eduarda Slhessarenko Fraife Barreto, MD1orcid_icon, Gabriel Pinheiro Martins de Almeida e Souza, MD1, Lara Santos Machado, MD1, Carlos Eduardo Cunha Hipolito, MD2, João Brainer Clares de Andrade, MD, PhD,1orcid_icon
1Division of Vascular Neurology, Department of Neurology, Universidade Federal de São Paulo, São Paulo, Brazil
2Department of Intensive Medicine, Universidade Federal de São Paulo, São Paulo, Brazil
Correspondence: João Brainer Clares de Andrade, MD, PhD Division of Vascular Neurology, Department of Neurology, Universidade Federal de São Paulo, Rua Napoleão de Barros 715, São Paulo 04024-002, Brazil Tel: +55-11-5576-4848, E-mail: joao.brainer@unifesp.br
Received 2025 May 30; Accepted 2025 June 5.

A 57-year-old woman underwent elective cerebral arteriography for evaluation of a known aneurysm located at the M1-M2 bifurcation of the right middle cerebral artery. During the procedure, the patient developed acute speech disturbance and right-sided weakness, without associated headaches, nausea, or vomiting. On neurological examination, the patient was lethargic and mildly confused, with Broca’s aphasia, leftward gaze deviation, and right hemiparesis. A non-contrast head computed tomography performed immediately after symptom onset revealed spontaneous hyperdensity within the subarachnoid space of the left hemisphere, consistent with subarachnoid hemorrhage (Fig. 1). The patient was promptly started on intravenous hydration and admitted to the intensive care unit (ICU) for close neurological monitoring. Several hours after admission, a single generalized seizure occurred, effectively managed with intravenous phenytoin; no maintenance anticonvulsive therapy was required. Infectious and metabolic evaluations were unremarkable. The patient remained under intensive supportive care and made a full neurological recovery within 48 hours. This case highlights the importance of recognizing contrast-induced encephalopathy as a stroke mimic [1], particularly in ICU settings, to avoid misdiagnosis and guide appropriate management [1-3].

Fig. 1.

(A) Initial non-contrast cranial computed tomography (CT) scan demonstrating asymmetric cortical spontaneous hyperdensity within the subarachnoid space of the left hemisphere, predominantly affecting the left parietal and occipital lobes. White arrow indicates the contrast distributed in the subarachnoid space. No associated mass effect or midline shift is observed. (B) Follow-up CT scan obtained 48 hours later reveals complete resolution of these findings. In conjunction with the clinical context, these imaging features support the diagnosis of contrast-induced-encephalopathy.

Notes

Ethics statement

The study was exempted from institutional review board (IRB) review. According to our local IRB rules, case reports do not need to be approved if informed consent from the patient was obtained. Informed consent was obtained from the patient.

Conflict of interest

No potential conflict of interest relevant to this article.

Author contributions

Conceptualization: MESFB. Methodology: MESFB. Formal analysis: JBCA. Data curation: MESFB, CECH. Visualization: GPMAS. Project administration: LSM. Writing - original draft: GPMAS, CECH. Writing - review & editing: JBCA.

References

1. Li J, Qi G, Zhang H, Chen G, Wang S, Yan M, et al. Contrast-induced encephalopathy mimicking stroke after a second cerebral DSA: an unusual case report. BMC Neurol 2021;21:430. 10.1186/s12883-021-02457-5. 34740313.
2. Saha A, Mitra S. Contrast-induced encephalopathy: a clinical conundrum. Cureus 2022;14:e31360. 10.7759/cureus.31360. 36523732.
3. Harada Y, Kairamkonda SR, Ilyas U, Pothineni NV, Samant RS, Shah VA, et al. Pearls & oy-sters: contrast-induced encephalopathy following coronary angiography: a rare stroke mimic. Neurology 2020;94:e2491–4. 10.1212/wnl.0000000000009590. 32381554.

Article information Continued

© 2025 The Korean Neurocritical Care Society

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Fig. 1.

Fig. 1.

(A) Initial non-contrast cranial computed tomography (CT) scan demonstrating asymmetric cortical spontaneous hyperdensity within the subarachnoid space of the left hemisphere, predominantly affecting the left parietal and occipital lobes. White arrow indicates the contrast distributed in the subarachnoid space. No associated mass effect or midline shift is observed. (B) Follow-up CT scan obtained 48 hours later reveals complete resolution of these findings. In conjunction with the clinical context, these imaging features support the diagnosis of contrast-induced-encephalopathy.