Microsurgical Findings of Tolosa-Hunt Syndrome

Background Tolosa-Hunt syndrome (THS), a nonspecific chronic inflammation of the cavernous sinus, is a rarely needed surgical manipulation, even for diagnosis, because corticosteroid therapy is markedly effective against this condition. Methods A 59-year-old man presented with left trigeminal neuralgia and right abducens nerve palsy 2 months after the improvement of right oculomotor nerve palsy by corticosteroid therapy. Radiological examinations showed a mass lesion in the left cavernous sinus. The clinical course indicated THS; however, hematological examination showed a positive tuberculous test. We performed a biopsy to rule out tuberculoma in the cavernous sinus. Results The biopsy was via a left frontotemporal interdural approach. The dura propria over the cavernous sinus was thickened and tightly adhered to the inner layer. The cavernous sinus was occupied by whitish elastic-hard tissue, and it was partially resected through the anterolateral triangle. Histopathological examination showed thick fibrous tissue with numerous degenerated cells and partial inflammatory cell infiltrations without any findings of tuberculoma. The final diagnosis was THS, and corticosteroid therapy was effective despite the chronic fibrous change of the cavernous sinus lesion. Conclusions This article presents details of surgical findings of THS that have not been demonstrated in any previous reports.