The criteria of the International Headache Society for Tolosa-Hunt syndrome need to be revised.

In 1988 the International Headache Society defined the diagnostic criteria of Tolosa-Hunt syndrome (THS) to include episode(s) of unilateral orbital pain for an average of 8 weeks if untreated, with associated paresis of one or more of the third, fourth, and sixth cranial nerves. Cranial nerve paresis may coincide with the onset of pain or follow it within a period of up to 2 weeks, and the pain must be relieved within 72 h after the initiation of corticosteroid therapy. Other causative lesions must be excluded by neuroimaging. On the basis of the history and neuroradiological findings of six patients we show the pitfalls in diagnosing THS with these criteria. We propose a revision of the criteria: Other causative lesions must be excluded by neuroimaging, especially of the region of the cavernous sinus and the orbita, and by blood and CSF examinations. Since imaging techniques have dramatically improved, it is now possible to visualize the inflammatory tissue in THS. Positive magnetic resonance imaging or computed tomography findings compatible with inflammatory tissue neither exclude nor confirm THS and remain suspect until a malignant tumor or inflammation other than THS is excluded. Clinical and radiological follow-up examinations must be performed for at least 2 years, even in patients with negative findings on magnetic resonance imaging at onset.