Oculomotor nerve schwannoma mimicking ophthalmoplegic migraine.

Ophthalmoplegic migraine (OM) is a rare variant of migraine characterized by recurrent attacks of severe headache followed by oculomotor nerve palsy. The recent revision of the International Headache Classification has reclassified OM from a subtype of migraine, defined as a functional headache, to the neuralgia category. We describe a case of an 11-year-old girl with pathologically confirmed oculomotor nerve schwannoma who had been suffering from symptoms mimicking OM. For five years, she has been under treatment for OM, an initial diagnosis which was corroborated by brain magnetic resonance imaging (MRI). Usually, most OM attacks occur during one period in a lifetime and remit completely. In contrast, however, her attacks became more frequent and were not controlled by medication. After surgery, the frequency of OM attacks was reduced. From this experience, we hypothesize that optic nerve tumor is one condition that can mimic OM, without apparent signs suggestive of intracranial mass. To our knowledge, this is the first report to describe a pathologically confirmed case of oculomotor nerve schwannoma mimicking OM.