Episodic neurologic dysfunction with migraine and reversible imaging findings after radiation.

Reported are three adults who developed frequent episodes of a complex neurologic syndrome years after radiation therapy for a brain tumor. MRI and [(18)F]fluorodeoxyglucose PET performed during the episodes demonstrated dramatic gyral thickening with enhancement and intense hypermetabolism in symptomatic regions that resolved on follow-up studies. EEG during episodes showed only slowing. The differential diagnosis and imaging findings are reviewed.