A Case of Normal Volume Hydrocephalus

ABSTRACT

The normal volume hydrocephalus is a serious, late complication of cerebrospinal fluid shunting procedures. It is characterized by persistent symptoms of headaches, vomiting and/or lethargy in shunted patients and is associated with normal-sized or slightly decreased ventricles. The subependymal gliosis that has been described in experimental and human hydrocephalus was offered as an explanation for the increased elastance in this condition. This 21-yearold male was shunted at 13 years of age for hydrocephalus secondary to pineal gland tumor. He remained asymptomatic for approximately 7 years before admission, when headaches and vomiting developed. A brain CT showed nearly normal-sized ventricles and spinal tapping documented elevated intracranial pressure (300mg CSF). A metrizamide shuntgram suggested obstruction of distal abdominal shunt catheter. After a revision of the distal shunt catheter, the patient became asymptomatic. On follow-up brain CT, no significant decrease in ventricle size was noted.