BACKGROUNDVentriculoatrial (VA) shunting has been superseded in popularity by the use of the peritoneal route (ventriculoperitoneal (VP)), mainly because of ease of insertion of the latter. However, a substantial number are still used, either as primary insertions or to replace a persistently failing VP shunt. 1 -3 In addition, a large but unknown number of patients with VA shunts remain in the community, usually without neurosurgical follow-up, 4 and may require medical attention at any time.VA shunt infections can be particularly diffi cult to diagnose because unlike VP shunt infections they often present long after shunt insertion with non-specifi c symptoms, and often to a specialty other than neurosurgery. Also, while VP shunt infection is often associated with distal obstruction, VA shunt infection does not usually compromise shunt function. Though Staphylococcus epidermidis is the most common cause of VA shunt infection it is also a universal skin commensal. Blood cultures are often negative or inconclusive and the signifi cance of a growth of S epidermidis can be diffi cult to determine. Ventricular cerebrospinal fl uid (CSF) aspirated from the shunt reservoir can also show no evidence of infection when only the shunt hardware is colonised, and there remains a diagnostic problem.Almost all VA shunt infections are contracted at the time of shunt insertion. S epidermidis is very adherent to shunt tubing, forming a biofi lm inside the shunt catheter, 5 -7 which periodically sheds into the bloodstream, repeatedly inoculating the patient. This causes a rising antibody titre to S epidermidis , which eventually leads to immune complex deposition and the problems that are associated with this, such as shunt nephritis. 8 If a VA shunt is infected for more than a year, immune complex disease can be the presenting problem, but it often manifests with non-specifi c or misleading symptoms such as vague joint or muscle pains, tiredness or skin rash. Here we present a patient with a VA shunt and non-specifi c symptoms and inconclusive laboratory results, where the diagnosis was eventually made with the assistance of serological testing.
CASE PRESENTATIONThe patient, a 38-year-old man with a Dandy Walker cyst and shunted hydrocephalus, had required several shunt revisions for malfunction and for infection as a child, the last one before this episode being at the age of nine, since when he had had a VP shunt. He was well until the age of 35, when he presented with headaches and abdominal pain. He underwent several revisions over the next year, but he continued to have abdominal pain so his shunt was revised to a VA shunt. The procedure was straightforward. He was asymptomatic when reviewed 3 months postoperatively. However, 7 months from the time of insertion he presented with severe headaches which were managed symptomatically. His symptoms resolved and he remained well for several months. After a further 4 months he presented with headaches and night sweats, and he was investigated for a possible shunt infection.
INVE...