Recurrent epileptic seizures following cardiac catheterization with iodixanol: a case report

BACKGROUND: Contrast-induced encephalopathy (CIE) is a rare complication of cardiac catheterization; clinical manifestations include cortical blindness, seizures and focal neurological deficits. In general, recurrent epileptic seizures following cardiac catheterization with iodixanol occur more rarely than do other complications. CASE PRESENTATION: Here, we report a case of a 76-year-old male patient who experienced unstable angina for nearly 10 months and was admitted to our hospital. Repeat cardiac catheterization was performed using iodixanol. At approximately 20 h after the first cardiac catheterization, his upper limbs began to exhibit slight trembling; the patient was conscious and could not control these movements. A total of 6 episodes occurred before the second cardiac catheterization was performed, with each episode lasting approximately 2 s. These symptoms were not treated. At approximately 2 h after the second cardiac catheterization, the symptoms became more severe, and the frequency of the episodes increased significantly; the symptoms had fully subsided at 6 h after the second operation. An electroencephalogram (EEG) demonstrated diffuse slowing with epileptiform abnormalities. Paroxysmal spike-wave and slow wave discharges were observed in the bilateral areas, and the abnormalities were marked in the frontal areas. These observations led us to conclude that the patient was experiencing epileptic seizures. During 6 months of monthly clinical follow-up visits after discharge, no abnormalities of the nervous system were found by cardiologists or neurologists, and the patient’s EEG was normal. No antiepileptic drugs were administered throughout this process. CONCLUSIONS: CIE, especially recurrent epileptic seizures, is a rare but often reversible complication of cardiac catheterization with iodixanol. Its symptoms can be mild and therefore are easily ignored by physicians. Early CIE detection may be achieved by EEG. Repeated exposure to contrast agents carries the risk of recurrent epileptic seizures.