[The diagnostic method of localization of cerebrospinal fluid rhinorrhea by digital video subtraction system]

Demonstration of the exact site of the dural fistula in cerebrospinal fluid rhinorrhea is difficult. Previous reports present the methods of metrizamide cisternography combined with both hypocycloid tomography and computed tomography. But in these methods, direct, dynamic, actual and real-time visualization of the fistula with minimal dose of metrizamide is rather difficult. By using digital video subtraction system (Philips DVI-2CV), we could visualize the direct, dynamic and actual site of fistula with small amount of metrizamide instilled into the suboccipital subarachnoid space with the patient prone position. We report a successful case of traumatic cerebrospinal fluid rhinorrhea drained through the bony defect at the planum sphenoid into the posterior ethmoid sinus. This is the first report to deal with the usefulness of digital video subtraction system for exact localization of cerebrospinal fluid rhinorrhea. We emphasize the usefulness of metrizamide cisternography by the digital video subtraction system combined with the metrizamide computed tomographic cisternography for the precise localization of dural fistula.