Tolosa-Hunt Syndrome - Cranial Neuroimaging Findings

The etiology of Tolosa-Hunt Syndrome (THS) is still unknown. The initial standard magnetic resonance imaging (MRI) may not be sufficient for diagnosis, so dynamic contrast-enhanced MRI may be necessary to demonstrate the presence of lesions.

Seven patients diagnosed with THS according to the International Headache Society criteria (beta version) were included into the study. Patients were assessed in terms of type, age, symptoms and findings, accompanying disease, localization of the determined lesion, response to treatment, and clinical progress. The "Tolosa-Hunt protocol" was applied in all patients, and the cavernous sinuses, orbital apices, and orbits were evaluated. The parameters used for the patients were as follows: Turbospin echo T1 and T2 weighted sequences on the axial plane, turbospin echo fat-saturated T2 weighted sequence on the coronal plane, turbospin echo T2 weighted sequence on the sagittal plane, spin echo fat-saturated T1 sequences repeated on the axial and coronal planes followed by intravenous administration of gadolinium. In all sequences the slice thickness was 3 mm.

Four of seven cases diagnosed with THS were males, and the average age of the patients was 45.7±18.1 years (range 25-69 years). A follow-up MRI in patient 5 after three months showed decreased signal intensity and enhancement of the affected cavernous sinus.

Conventional MRI may be insufficient to show the granulomatous inflammation, and an MRI method referred to as the Tolosa-Hunt protocol should be applied to those who are thought to have THS.