Contrast-Induced Neurotoxicity Following Mechanical Thrombectomy for Acute Left MCA Occlusion: A Reversible Radiological Mimic of Intracranial Haemorrhage.

Introduction: Neurotoxicity due to contrast extravasation and disruption of the blood-brain barrier is a rare event in neuroendovascular procedures called contrast-induced neurotoxicity (CIN). Although a correct diagnosis may be difficult after mechanical thrombectomy, radiologically, CIN may be similar to haemorrhage or malignant oedema. Case description: A 59-year-old male with a history of hypertension, paroxysmal atrial fibrillation and recent non-ST-elevation myocardial infarction presented with acute ischemic stroke secondary to distal left middle cerebral artery occlusion. There was successful reperfusion with mechanical thrombectomy. The immediate post-procedure computed tomography scan revealed hyper attenuation of the left frontotemporal gyral with oedema, but no evidence of haemorrhage, which matched with the diagnosis of CIN. Rapid healing of hyper attenuation and evolution to a stable infarct was observed on serial computed tomography scans obtained over 24-48 hours. The patient needed prolonged ventilatory support, which was provided by a tracheostomy and there was no haemorrhagic transformation. Conclusion: This case serves as an example of a benign radiological mimic after thrombectomy, namely CIN. Understanding its imaging appearances and the need for serial CT imaging helps to prevent misdiagnosis and unnecessary discontinuation if anti-thrombotic treatment. There is no evidence of self-limitation and there is support for management of CIN. LEARNING POINTS: Mechanical thrombectomy can also cause rare and reversible side effects of contrast-induced neurotoxicity (CIN) that can mimic immediately post-procedure computed tomography (CT) scan findings of intracranial bleeding.Non-contrast CT imaging is crucial to rule out malignant cerebral oedema or haemorrhagic transformation of the stroke lesion, especially in the case of serial imaging, to avoid unnecessary interventions.In patients with cardioembolic stroke and high-risk, antithrombotic therapy can be continued at the time of recognition of CIN.