A Case of Spontaneous Third Ventriculocisternostomy to the Interpeduncular Fossa.

Background: Triventricular hydrocephalus is caused by an obstruction of cerebrospinal fluid flow causing increased intracranial pressure (ICP). Common treatment options include ventricular shunting or endoscopic third ventriculocisternostomy. Spontaneous third ventriculocisternostomy is a rare phenomenon in patients with obstructive triventricular hydrocephalus. We present the case of a patient with triventricular hydrocephalus and evidence of spontaneous third ventriculocisternostomy.

Case Description: A 33-year-old female patient was referred to our outpatient clinic for triventricular hydrocephalus diagnosed on imaging. Magnetic resonance imaging (MRI) of her brain showed a triventricular obstructive hydrocephalus owing to a possible aqueductal stenosis. No clinical or diagnostic signs of elevated ICP were present. Repeat imaging showed no changes in cerebral ventricular size and MRI flow imaging demonstrated flow voids in the third ventricle extending through the floor of the third ventricle to the prepontine cistern. We concluded that the cause of hydrocephalus was likely to be a compensated aqueductal stenosis.

Conclusions: Spontaneous third ventriculocisternostomy is seen in patients with chronic hydrocephalus. MRI sensitive to flow artefacts can be useful in the diagnosis of patients with apparent compensated hydrocephalus, and phase-contrast imaging can prove cerebrospinal fluid flow across the stoma. Resolution of symptoms owing to elevated ICP is regularly observed in patients with a spontaneous ventriculocisternostomy.