Localization of dural fistulas using metrizamide digital subtraction fluoroscopic cisternography

✓ Demonstration of the exact site of dural fistulas in cases of cerebrospinal fluid rhinorrhea is difficult. Previous reports have described the use of metrizamide cisternography combined with either hypocycloidal tomography or computerized tomography; however, direct, dynamic, real-time visualization of the fistula is difficult with instillation of a minimal dose of metrizamide using those methods. A digital video subtraction fluoroscopy system can visualize the actual site of the fistula directly and dynamically using only a small amount of metrizamide.

Intermittent Cerebrospinal Liquorrhea

Eight patients with posttraumatic intermittent rhinoliquorrhea were examined in the dry non-drop period, seven of them with CT metrizamide cisternography. The evidence of fracture of the skull base in combination with protruding soft tissues into the sinuses, a local deformity of basal sulci, and pooling of contrast medium in a dural pouch or herniated soft tissue plug will localize the site of leakage. There is no need for special maneuvers such as raising the intracranial pressure in order to initiate flow of the cerebrospinal fluid. Criteria for localizing the leakage are discussed.

Localisation of a CSF fistula by metrizamide CT cisternography

Localisation of a cerebrospinal fluid fistula in the nasal region is difficult. Lack of a suitable roentgen contrast medium for intrathecal use has earlier restricted theutility of cisternography. Metrizamide cisternography and CT have recently proved to be well tolerated and effective in revealing CSF fistulae. A case report of operatively treated CSF rhinorrhea recurring after three years is presented. With the help of CT metrizamide cisternography, the fistula could finally be localised in the sphenoidal sinus. The re-operation confirmed this finding. The technique of cisternography is described.

Recurrent Bacterial Meningitis: Coronal Thin-Section Cranial Computed Tomography to Delineate Anatomic Defects

Three patients with histories of recurrent bacterial meningitis were previously examined with skull and sinus radiographs, routine cranial computed tomography, intrathecal radioisotope tracer studies, and immunologic evaluation. None of these studies were diagnostic. Pneumococcal vaccine and prophylactic penicillin therapy were ineffective in preventing recurrent episodes in two cases. Thin-section (2-mm) direct coronal computed cranial tomography demonstrated anatomic defects in all three patients. The use of metrizamide cisternography was not necessary to diagnose the defects. All patients had basiethmoidal encephaloceles which were repaired surgically. Direct coronal computed tomography offers a relatively easy noninvasive method for delineating anatomic abnormalities in patients with recurrent meningitis.

Symptomatic Rathke's Cleft Cysts Located Entirely in the Suprasellar Region: Review of Diagnosis, Management, and Pathogenesis

Three cases of an entirely suprasellar symptomatic Rathke's cleft cyst, two of which were associated with normal sella turcicas, are reported. In all cases, the cysts caused compression of the optic chiasm, and two produced hypothalamic dysfunction. The diagnosis of these entirely suprasellar masses was enhanced by metrizamide cisternography. Two cases were treated by frontal craniotomy and one was treated transsphenoidally, with good results in all cases. The radiology, pathology, and surgical treatment of these unusual cases is presented. An embryological pathogenesis for the occurrence of an entirely suprasellar Rathke's cleft cyst is discussed.

Posttraumatic cerebrospinal fluid cyst of the orbit

✓ A 27-year-old man sustained a fracture of the orbital roof and a basofrontal dural tear in a motor-vehicle accident. One week later, he developed an orbitocranial dural fistula manifested by an orbital cyst, pulsatile proptosis, and serous drainage from the eye. Specific diagnosis was established only after computerized tomography metrizamide cisternography demonstrated direct communication of the orbital cyst with the subarachnoid space. The pertinent literature is reviewed.

Neuroepithelial Cysts of the Posterior Fossa: Pathogenesis and Report of Two Cases

We present two cases of simple neuroepithelial cyst-one at the cerebellopontine angle and the other in the pontine brain stem-in which a basement membrane was detected. The pathogenesis of these cysts, their diagnosis using computed tomography-metrizamide cisternography and nuclear magnetic resonance imaging, and their surgical treatment by fenestration and drainage are discussed.