Iodinated Contrast Encephalopathy after Coil Embolization of Unruptured Aneurysms

Iodinated contrast encephalopathy is known as one of the rare complications of cerebral angiography and neurovascular intervention. The mechanism and causes of contrast encephalopathy are not understood well. In this case, we experienced transient neurological deficit following coil embolization of unruptured aneurysms. A 67-year-old woman with two unruptured aneurysms of internal carotid artery underwent endovascular coil embolization. During the procedure, she presented transient hemiparesis and aphasia. After the treatment, she presented the symptom again, and computed tomography scan showed cortical edema and subarachnoid leakage of contrast agent. Magnetic resonance imaging excluded cerebral infarction. The neurological symptom resolved completely within 24 h after the treatment, and she was diagnosed as the contrast encephalopathy. In our case, we speculated that contrast encephalopathy has occurred subsequently to the transient cerebral ischemia. Iodinated contrast encephalopathy may have induced with neurovascular intervention following cerebral ischemia and increased use of contrast agent. We should consider iodinated contrast encephalopathy when a patient presents hemiparesis and aphasia such as that caused by acute stroke during neurovascular intervention.