Bilateral duplication of the abducens nerves: an incidental finding on magnetic resonance imaging.

Although anomaly of the abducens nerve, including duplication, has been reported in anatomical papers, no radiological report exists regarding a duplicated abducens nerve observed on magnetic resonance (MR) imaging. We encountered a case of bilateral duplication of the abducens nerves, which was found incidentally on MR scans from an 11-year-old boy. He did not have any symptoms of eye movement related to abducens nerve abnormality; thus, the duplication was considered to be a normal variant in this patient. Radiologists should be aware that duplication of the abducens nerve may occur and can be diagnosed on MR, particularly when diagnosing symptomatic patients or as a preoperative assessment for microsurgery of the nerve.