Seizure as a manifestation of intracranial hypotension in a shunted patient.

The authors describe a child with a ventriculo-peritoneal shunt in place for 5 years who presented with 'postural' seizures (seizures on sitting upright, which resolved on recumbency). On shunt tap, the cerebrospinal fluid was obtained freely, but required gentle aspiration with a syringe in the recumbent position, suggesting very low intracranial pressure. Contrast magnetic resonance imaging showed pachymeningeal enhancement and enlargement of the pituitary gland diagnostic of intracranial hypotension along with well-decompressed ventricles. At the time of revision of the shunt, no evidence of malfunction was found and the valve was changed to one with a higher opening pressure. Following this, she became asymptomatic and seizure free. This case illustrates the fact that following shunting, intracranial hypotension may also predispose to seizures, and should be kept in mind while managing these patients.