metrizamide and Rupture--Spontaneous

Epidermoid cysts originating in the paramedian basal cisterns of the posterior fossa are congenital lesions that grow to a large size through slow accumulation of desquamated epithelium. These lesions grow between and ultimately displace cranial nerves, vascular structures, and the brain stem, causing a long course of progressive neurological deficits. The onset of symptoms usually occurs during the fourth decade of life. Epidermoid cysts are easily diagnosed with computerized tomography scans, which characteristically show a low-density extra-axial pattern. The primary surgical objective is to decompress the mass by evacuating the cyst contents and removing nonadherent portions of the tumor capsule; portions of the capsule adherent to vital structures should be left undisturbed. Aseptic meningitis is the most common cause of postoperative morbidity, and its incidence may be minimized by intraoperative irrigation with steroids followed by systemic therapy with dexamethasone. Symptomatic recurrences that occur many years after surgery should be managed with conservative reoperation.

Topics: Adult; Aged; Brain Diseases; Cranial Fossa, Posterior; Epidermal Cyst; Female; Humans; Male; Meningitis, Aseptic; Methods; Metrizamide; Middle Aged; Postoperative Complications; Rupture, Spontaneous; Tomography, X-Ray Computed

Spontaneous ventriculocisternostomy rarely occurs in obstructive hydrocephalus. The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300 mmH2O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. In the literature, arrest of hydrocephalus was noted in 50 per cent of 14 cases of obstructive hydrocephalus with spontaneous ventriculocisternostomy. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy.

Topics: Adult; Cerebral Ventriculography; Humans; Hydrocephalus; Iothalamate Meglumine; Male; Metrizamide; Pneumoencephalography; Rupture, Spontaneous; Subarachnoid Space; Tomography, X-Ray Computed

The authors report a case of a dermoid cyst in the right anterior cranial fossa, which communicated spontaneously with both the subarachnoid space and the lateral ventricle. The communication was demonstrated by metrizamide computed tomographic cisternography before operation and was verified during operation.

Topics: Brain Neoplasms; Cerebral Ventricles; Dermoid Cyst; Humans; Male; Metrizamide; Middle Aged; Rupture, Spontaneous; Subarachnoid Space; Tomography, X-Ray Computed