The Australian Diagnostic Criteria for Contrast-Induced Encephalopathy.Neuroradiology • November 10, 2024
Frederick Mariajoseph, Leon Lai, Adrian Praeger, Ronil Chandra, Justin Moore, Hamed Asadi, Laetitia De Villiers, Tony Goldschlager, Calvin Gan, Kevin Zhou, Albert Ho Chiu, Ferdinand Miteff, Ramon Banez, Thanh Phan, Davor Pavlin Premrl, Winston Chong, Sophie Dunkerton, Anoop Madan, Lee-anne Slater
Background: Contrast-induced encephalopathy (CIE) is a recognised complication of contrast administration, however diagnosis remains challenging due to its symptom overlap with other neurological conditions and the absence of formal diagnostic criteria.
Methods: A modified Delphi study was performed. Consultant physicians with active clinical experience with CIE patients were invited from neurovascular centres in Australia. Initial diagnostic items were derived from an extensive literature review and analysis of local institutional cases across Australia. Three Delphi rounds were conducted. Consensus was defined as ≥ 75% agreement.
Results: Seventeen neurovascular specialists from nine neurovascular centres participated (81.0% response rate) between May 2024 and July 2024. In round 1, 15 diagnostic items were presented to participants, which were revised and one additional criteria suggested. In round 2, 14/16 diagnostic items achieved consensus. In round three 14/14 items achieved consensus. Ultimately, a 14-item diagnostic criteria was developed based on participant consensus. The absolute criteria exclude CIE if symptom onset is more than 24 h after contrast administration, or if symptoms can be explained by vessel occlusion/territory ischaemia, intracranial haemorrhage, epilepsy, metabolic derangement, intracranial malignancy or head trauma. The supporting criteria indicate that CIE is more probable if symptoms are reversible, correspond with the distribution of contrast administration, or are associated with reversible contrast staining, cerebral oedema or cortical/subcortical MRI signal change.
Conclusions: This study proposes a 14-item diagnostic criteria for CIE based on expert consensus in Australia. Further research is needed to refine CIE as a clinical entity.
Treatment of contrast induced encephalopathy: multicenter cohort study and proposed treatment algorithm.Journal Of Neurointerventional Surgery • April 21, 2025
Frederick Mariajoseph, Leon Lai, Adrian Praeger, Justin Moore, Ronil Chandra, Hamed Asadi, Peter Fawzy, Laetitia De Villiers, Tony Goldschlager, Albert Ho Chiu, Boaz Kim, Ferdinand Miteff, Ramon Martin Bañez, Davor Pavlin Premrl, Winston Chong, Robert Fang, Kate Mahady, Sophie Dunkerton, Brendan Steinfort, Bjoern Picker, Lee-anne Slater
Background: Contrast induced encephalopathy (CIE) is an increasingly recognized but uncommon complication of endovascular procedures. Despite increased reports, there is limited evidence to guide clinical management. We sought to identify commonly used treatments for CIE and propose management strategies to aid clinical decision making.
Methods: A retrospective multicenter study was conducted across 10 neurovascular centers in Australia. Cases were included based on previously proposed diagnostic criteria for CIE. Clinical features, treatments, and outcomes were extracted and analyzed. Descriptive statistics were used to characterize management strategies, and associations with clinical outcomes were assessed using Fisher's exact and χ2 tests.
Results: 56 patients were identified (median age 65 years; 80.4% women). Common interventions included corticosteroids (66.1%), intravenous fluids (66.1%), and antiseizure medications (prophylactic 51.8% and therapeutic 12.5%). Half required intensive care admission for neurological monitoring. Complete recovery was achieved in 87.5% of cases. Corticosteroid administration was significantly associated with symptom resolution within 72 hours (OR 4.51, 95% CI 1.19 to 17.85, P=0.022), while intravenous fluids showed a non-significant trend toward shorter symptom duration (OR 2.25, 95% CI 0.64 to 8.15, P=0.170).
Conclusions: CIE generally carries a favorable prognosis. Corticosteroids appeared to shorten symptom duration and may be considered in management. Based on our findings and the existing literature, we propose a treatment algorithm to guide clinicians. Prospective validation is warranted.
Nationwide multicenter experience of contrast-induced encephalopathy following neurointervention: clinical course and outcomes.Journal Of Neurointerventional Surgery • April 15, 2025
Frederick Mariajoseph, Leon Lai, Adrian Praeger, Justin Moore, Ronil Chandra, Hamed Asadi, Peter Fawzy, Laetitia De Villiers, Tony Goldschlager, Calvin Gan, Kevin Zhou, Albert Ho Chiu, Boaz Kim, Ferdi Miteff, Ramon Martin Bañez, Davor Pavlin Premrl, Winston Chong, Robert Fang, Kate Mahady, Sophie Dunkerton, Brendan Steinfort, Bjoern Picker, Lee-anne Slater
Background: Contrast-induced encephalopathy (CIE) is an increasingly observed complication following neurointervention, but remains poorly defined with limited evidence for clinical decision-making. We sought to characterize the stereotypical clinical features of CIE in a nationwide, multicenter cohort.
Methods: A multicenter cohort study was conducted between 10 neurovascular sites across Australia. Patients were screened according to the previously proposed Australian diagnostic criteria. Descriptive analysis was conducted to characterize the clinical course and outcomes of CIE, and associations between clinical and radiological variables on patient outcomes were analyzed using Fisher's exact and χ2 tests.
Results: A total of 56 patients (median age 65 years) were included. The median contrast volume was 170 mL (IQR 140-229). Median time to symptom onset was 6 hours (IQR 1-12), with frequent symptoms including motor deficit (55.4%), dysphasia (39.3%), and confusion (35.7%). Common radiological findings included sulcal effacement (45.5%) and subarachnoid contrast staining (30.9%) on CT. Hemianopia (p=0.001) and cortical blindness (p=0.018) were associated with posterior circulation interventions, while motor deficit was correlated with anterior circulation interventions (p=0.001). At discharge, 87.5% of patients achieved complete resolution of symptoms, of which 69.4% achieved complete recovery within 72 hours.
Conclusions: CIE is a recognized complication of neurointervention. Symptoms occur within hours of contrast administration and correlate with the territory of contrast administration. Most patients achieve complete symptom resolution. Ongoing investigation is required to further define CIE as a clinical entity.
Incidence of contrast-induced neurotoxicity following endovascular treatment of unruptured intracranial aneurysms: a single-centre cohort study.Acta Neurologica Belgica • August 04, 2024
Frederick Mariajoseph, Leon Lai, Justin Moore, Ronil Chandra, Tony Goldschlager, Adrian Praeger, Daniel Yu, Lee-anne Slater
Background: Contrast-induced neurotoxicity (CIN) is a recognised complication of endovascular procedures and has been increasingly observed in recent years. Amongst other clinical gaps, the precise incidence of CIN is unclear, particularly following intracranial interventional procedures.
Methods: A retrospective study of consecutive patients undergoing elective endovascular treatment of unruptured intracranial aneurysms (UIAs) was performed. Patients with previously ruptured aneurysms were excluded. The primary aim of this study was to determine the incidence of CIN following endovascular UIA treatment. Our secondary aim was to isolate potential predictive factors for developing CIN.
Results: From 2017 to 2023, a total of 158 patients underwent endovascular UIA treatment, with a median age of 64 years (IQR: 54-72), and 70.3% of female sex. Over the study period, the crude incidence of CIN was 2.5% (95% CI: 0.7 - 6.4%). The most common clinical manifestation of CIN was confusion (75%) and seizures (50%). Statistical analysis was conducted, and prolonged procedural duration was found be significantly associated with developing CIN (OR 12.55; p = 0.030).
Conclusions: Clinicians should be aware of the risk of CIN following endovascular neurointervention, particularly following technically challenging cases resulting in prolonged procedural time.
Neuroradiological features of contrast-induced neurotoxicity: A systematic review and pooled analysis.Journal Of Clinical Neuroscience : Official Journal Of The Neurosurgical Society Of Australasia • April 19, 2024
Frederick Mariajoseph, Daniel Yu, Leon Lai, Justin Moore, Tony Goldschlager, Ronil Chandra, Adrian Praeger, Lee-anne Slater
Background: Contrast-induced neurotoxicity (CIN), is an increasingly recognised complication of endovascular procedures, presenting as a spectrum of neurological symptoms that mimic ischaemic stroke. The diagnosis of CIN remains a clinical challenge, and stereotypical imaging findings are not established. This study was conducted to characterise the neuroimaging findings in patients with CIN, to raise diagnostic awareness and improve decision making.
Methods: We performed a systematic review of PubMed and Embase databases from inception (1946/1947) to June 2023 for reports of CIN following administration of iodinated contrast media. Studies with a final diagnosis of CIN, which provided details of neuroimaging were included. All included cases were pooled and descriptive analysis was conducted.
Results: A total of 84 patients were included, with a median age of 64 years. A large proportion of patients had normal imaging (CT 40.8 %, MRI 53.1 %). CT abnormalities included cortical/subarachnoid hyperattenuation (42.1 %), cerebral oedema/sulcal effacement (26.3 %), and loss of grey-white differentiation (7.9 %). Frequently reported MRI abnormalities included brain parenchymal MRI signal change (40.8 %) and cerebral oedema (12.2 %), most commonly observed on FLAIR sequences (26.5 %). Characterisation of imaging findings according to anatomical location and clinical symptoms has been conducted.
Conclusions: Neuroimaging is an essential part of the diagnostic workup of CIN. Analysis of the anatomical location and laterality of imaging abnormalities may suggest relationship between radiological features and actual clinical symptoms, although this remains to be confirmed with dedicated study. Radiological abnormalities, particularly CT, appear to be transient and reversible in most patients.