Possibility of arterial spin labeling perfusion magnetic resonance imaging sequences with steroid therapy for Tolosa-Hunt syndrome: A case report and review of literature

BACKGROUND: The diagnostic criteria for Tolosa-Hunt syndrome (THS) were updated in 2013 in the 3(rd) Edition of the International Classification of Headache Disorders. It is now possible to diagnose THS based on the presence of granulomatous inflammation demonstrated on magnetic resonance imaging (MRI) without confirmation by biopsy. No previous study has reported the use of arterial spin labeling (ASL) perfusion MRI for diagnosing THS. Here, we report a case of THS in which ASL was used in the initial identification and to monitor therapeutic response following steroid therapy. CASE DESCRIPTION: An 86-year-old man was complaining chiefly of the left orbital pain, as well as occipital pain, nausea, epiphora, and diplopia. Neurologically, his eye movements showed left adduction disorder and palsy of the right cranial nerve III. Magnetic resonance angiography revealed no abnormality in the left internal carotid artery. Contrast-enhanced MRI showed a region of slightly high signal in the left cavernous sinus. ASL was obtained using pCASL (TR/TE, 9000/98. 48 ms; postlabeling delay: 1525 ms; axial plane) revealed hyperperfusion from the intercavernous sinus to the vicinity of the left cavernous sinus due to a local increase in cerebral blood flow. The symptoms disappeared on day 62 of the treatment and he was in complete remission. Follow-up ASL was performed every other month showed reduced perfusion as the symptoms improved and confirmed the absence of a tumor over the follow-up period. CONCLUSION: This simple technique will play an important role in confirming no recurrence after steroid therapy treatment.