Negative-Pressure Hydrocephalus Treated with a Modified Shunt System: A Case Report

A negative-pressure hydrocephalus (NePH) is a rare type of hydrocephalus characterized by the presence of negative intracranial pressure (ICP) and ventriculomegaly. Despite the low or negative ICP, patients with NePH often develop symptoms consistent with high ICP, and they frequently deteriorate. Several hypotheses have been proposed to demonstrate the underlying pathophysiology in NePH, but the exact mechanism still remains unclear. Multiple treatment options have been suggested, including the identification and repair of cerebrospinal fluid (CSF) leak, subatmospheric external ventricular drains (EVD), neck wrapping, or placement of CSF shunts. In this study, we present a case of a NePH patient refractory to the standard CSF shunt procedure and successfully treated with a modified ventriculoperitoneal shunt system. A negative-pressure hydrocephalus (NePH) is a rare type of hydrocephalus that is symptomatic despite the negative intracranial pressure (ICP). Because of the shortcomings of the existing shunt system that could not produce the necessary gradient for an effective cerebrospinal fluid (CSF) drainage in NePH patients, a refined method for CSF drainage is needed. We combined the traditional low-pressure valve with a distal catheter, which has no end hole and only has side slits, to prevent the CSF backflow and facilitate the siphon effect. Simultaneously, the active pumping of the shunt reservoir was also conducted to remove the excess CSF from the ventricular system. The treatment of NePH requires an appropriate reduction of excessive CSF until the CSF dynamics and brain compliance are restored. We suggest the use of this modified shunt system for NePH treatment, as it is easily modifiable and has sufficient effects.