Ventriculoperitoneal shunt overdrainage

Background

• Overdrainage -> tissue occluding the orifices of the proximal shunt apparatus
  • As pressure increases the occluding tissue diesengages allowing drainage to resume
  • Leads to cyclic increased ICP complaints that worsen when patient stands
  • Newer valve devices with antisiphon features make this less common

Clinical Features

• Vague symptoms of dizziness, visual distubances
• Worsened with standing/exertion

Differential Diagnosis

Ventriculoperitoneal shunt problems

• Ventriculoperitoneal shunt obstruction
• Ventriculoperitoneal shunt overdrainage (Slit Ventricle Syndrome)
• Ventriculoperitoneal shunt infection
• Ventriculoperitoneal shunt mechanical failure

Evaluation

• CT Head necessary for shunt placement workup and overdrained ventricles
• Patients at higher risk for subdural hematomas

Disposition

• Admission for shun revision versus valve adjustment