Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction

Abstract

It is probable that in obstructive hydrocephalus, at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain. Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.

Endoscopic Intraventricular Surgery for Treatment of Hydrocephalus and Loculated CSF Space in Children Less than One Year of Age

“…The observation that children younger than 1 year have a greater likelihood than older children to fail third ventriculostomy was not confirmed in the series of Cinalli et al [1, 2]. The only difference they found in regard to infant age was that failure in the children younger than 6 months usually occurred sooner after the procedure compared to older children.…”

“…Analysis of the outcomes and costs of the treatment of hydrocephalic infants reveals a significant number and percentage of complications and shunt revisions [1, 2, 12, 13, 14, 15]. It is estimated that about 25–40% of all shunts fail within 1 year of insertion, and that the failure rate in children younger than 1 year is even higher [16, 17].…”

“…Obstruction after ventriculostomy has been observed both radiographically and endoscopically and may take up to 2 years [1, 2]. …”

“…The procedure is safe and reliable and effectively controls hydrocephalus in about 70% of appropriately selected pediatric patients [1, 2]. The procedure is indicated in patients with obstruction due to primary aqueductal stenosis, toxoplasmosis and tectal, pineal or posterior thalamic tumors.…”

Pressure compensation in shunt-dependent hydrocephalus with CSF shunt malfunction

“…IV ventricular shunt malfunction which may not be reflected in pressure measurements from the lateral ventricles [1], and therefore we have included only those cases of hydrocephalus with a ventriculoperitoneal shunt where the measured ICP would normally be relied upon to decide if the shunt were functioning. This applied to 56 cases over a 3 year period, with pressure recordings and additional blood pressure measurements (Dynamap) being available in 48 of these patients, allowing the calculation of the CPP to be made.…”