Pre-operative identification of a dural defect using T2*-reversed magnetic resonance imaging in a spinal extradural arachnoid cyst: A case report

Background: Spinal extradural arachnoid cysts (SEACs) are rare lesions that can cause progressive neurological symptoms due to spinal cord compression. Typically, these cysts are connected to the intradural subarachnoid space through a small defect in the dural sac. Surgical repair requires accurate identification of the dural defect; however, pre-operative localization remains challenging. We report a case of a SEAC in which the location of a dural defect was suggested preoperatively with the use of T2*-reversed magnetic resonance imaging (MRI). Case Description: A 62-year-old woman presented to our hospital with a known thoracic cystic lesion and worsening urinary frequency and neurological symptoms. She presented with lower-extremity hyperreflexia, right iliopsoas weakness, deep sensory disturbance in the right lower limb, urinary frequency, and headache. Pre-operative MRI demonstrated a cystic lesion extending from Th (thoracic) 12 to L (lumber) 1. Notably, T2*-reversed imaging suggested a dural defect at the right lateral aspect of Th12. The patient was diagnosed with a SEAC, and surgical exploration confirmed a dural defect at the predicted site, which was directly sutured. Postoperatively, the cyst markedly decreased in size, and the patient’s symptoms gradually improved. Conclusion: We report a case of a SEAC, focusing on pre-operative localization of a dural defect. This case suggests the potential usefulness of T2*-reversed MRI for pre-operative localization of dural defects in SEACs.