Obstructive hydrocephalus

This patient has severe obstructive hydrocephalus due to a tumour of the tectal plate . The patient was treated by third ventriculostomy. The immediate preoperative image on the left shows marked dilatation of the lateral and third ventricles. The corpus callosum is thinned and elevated. The fornices are depressed. The floor of the 3rd ventricle is plastered to the skull base, obliterating the suprasellar cistern. The infundibular and optic recesses are rounded. The pineal recess is also rounded, but the suprapineal recess appears deficient or ballooned. There is a cystic structure (large grey arrows) interposed between the tentorium cerebelli and the superior cerebellum, with marked mass effect. There is marked tonsillar herniation, which is probably due to a combination of posterior fossa mass effect and a Chiari type I malformation.

Immediate postoperative imaging (right) shows reduction in the degree of hydrocephalus. The suprasellar cistern is no longer effaced, and the infundibular recess is sharper. The optic and pineal recesses remain rounded, although there is a definite improvement. The posterior fossa cystic structure has also reduced in size, consistent with a communication with the third ventricle - the cyst actually represents a herniation via the suprapineal recess. The tonsillar herniation has improved, as has effacement of CSF at the craniocervical junction.

Reference

Osborn AG, Blaser SI, Salzman KL. Brain: Top 100 Diagnoses Amirsys 2004

Chronic obstructive hydrocephalus with fenestration of the septum pellucidum

Tectal glioma in an 18 year old. Note features of chronic hydrocephalus.

Image courtesy of Dr Frank Gaillard

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From the case: Aqueductal stenosis

From the case: Arachnoid cyst (posterior fossa) with hydrocephalus

From the case: Tectal Plate Low Grade Glioma with Hydrocepalus

From the case: Tectal Plate Low Grade Glioma with Hydrocepalus

From the case: Tectal Plate Low Grade Glioma with Hydrocepalus