Ophthalmoplegic migraine with reversible enhancement of intraparenchymal abducens nerve on MRI.

We describe a patient with ophthalmoplegic migraine and right abducens nerve palsy, in whom serial magnetic resonance imaging showed a transient, gadolinium-enhancing lesion in the right lower pons, during both headache and the headache-free period. The enhancing linear lesion was felt to represent intraparenchymal fibers of the affected abducens nerve. The possible pathophysiology of this unique finding is discussed.