Transient binocular visual loss: a rare presentation of ventriculoperitoneal shunt malfunction.

The authors report the case of a 27-year-old male with ventriculoperitoneal shunt (VPS) for hydrocephalus presenting with episodic transient binocular visual loss (TBVL) and headache. Complete physical, bedside shunt examination and funduscopy were unremarkable. Laboratory investigation, shunt series and imaging studies failed to reveal any acute abnormalities. Interrogation of the shunt system identified a valve malfunction which was corrected with resultant symptomatic relief and the patient was discharged home in stable condition. VPS malfunction occurs secondary to infection or mechanical failure such as obstruction, tubing fracture, shunt migration and over drainage. Resultant raised intracranial pressure leads to symptoms of headache, nausea, vomiting and gait abnormalities. Visual defects including blindness has been occasionally reported from shunt malfunction. Rare complications include cerebrospinal fluid oedema, colonic perforation, paraparesis and parkinsonism. TBVL due to shunt malfunction remains an uncommon presentation and requires a high index of clinical suspicion while evaluating these patients.