The usefulness of ultrasonographic assessment of ventricle-peritoneal shunt function in the case of a Chiari type 2 malformation

A patient with a Chiari type 2 malformation underwent repair of a myelomeningocele 3 days after birth and received a ventricle-peritoneal shunt for congenital hydrocephalus 70 days after birth at another hospital. Later, he was brought to our hospital because of suspected shunt malfunction. A new shunt system was inserted when the patient was 18 months of age. We used transcranial sonography (TCS) to measure the cerebral ventricle size in preparation for postoperative shunt pressure adjustment. We had a problem in controlling the shunt function between the old tube and the new tube. By using TCS, we could immediately confirm the change in the ventricle size after pressure adjustment without frequent examinations by computed tomography or magnetic resonance imaging. The child’s mother was later found to have Munchausen syndrome by proxy. The clue to this diagnosis was the dissociation between the mother’s complaints and the child’s actual status, including the child’s shunt function assessed by TCS.