Digital Subtraction Cystography for Detection of Communicating Holes of Spinal Extradural Arachnoid Cysts

OBJECTIVE: The purpose of this study was to demonstrate the usefulness of digital subtraction cystography to identify communicating holes between a spinal extradural arachnoid cyst (SEAC) and the subarachnoid space prior to cyst removal and hole closure. MATERIALS AND METHODS: Six patients with SEAC were enrolled in this retrospective study. Digital subtraction cystography and subsequent CT myelography were performed for every patient. The presence and location of the communicating holes on cystography were documented. We evaluated the MRI characteristics of the cysts, including location, size, and associated spinal cord compression; furthermore, we reviewed cystographic images, CT myelograms, procedural reports, and medical records for analysis. If surgery was performed after cystography, intraoperative findings were compared with preoperative cystography. RESULTS: The location of the communicating hole between the arachnoid cyst and the subarachnoid space was identified by digital subtraction cystography in all cases (n = 6). Surgical resection of SEAC was performed in 4 patients, and intraoperative location of the communicating hole exactly corresponded to the preoperative identification. CONCLUSION: Fluoroscopic-guided cystography for SEAC accurately demonstrates the presence and location of dural defects. Preoperative digital subtraction cystography is useful for detection of a communicating hole between a cyst and the subarachnoid space.

Septated Extradural Arachnoid Cyst in Thoracolumbar Spine Causing Myelopathy

Spinal extradural arachnoid cyst is uncommon and rarely cause neural compression. We report a rare case of severe cord compression due to septated spinal extradural arachnoid cyst. A 35-year-old woman has developed back pain 3 months prior to her visit, but recently motor weakness and urinary incontinence occurred. Magnetic resonance images showed an extradural cyst posterior to the cord, which was flattened and displaced from T12 to L2. Urgent decompressive laminectomy and cyst removal was performed. Histopathological examination confirmed that cyst wall was formed by nonspecific fibrous connective tissue without a single-cell layer of inner arachnoid lining. Motor weakness and voiding difficulty were recovered completely after operation.