"There is no way to cure or prevent hydrocephalus. For the past forty years the most effective treatment has been the surgical insertion of a shunt. The one you've brought is a bit outdated, but it's real y pretty typical.

"Most shunts are just flexible tubes placed into the ventricles to divert the flow of CSF. They consist of a system of tubes with a valve to control the rate of drainage and to prevent back flow. The early ones diverted the accumulated CSF into a vein in the neck, then into the right atrium of the heart. Those are cal ed ventriculo-atrial, or VA shunts. Some VA shunts are stil used, but there are problems associated with them, including infection, and, though rare, heart failure due to blockage of blood vessels within the lungs by particles of blood clot flaking off the shunt's catheter tip. Most shunts now drain into the peritoneal cavity. They're cal ed VP shunts."

She indicated the device I'd pul ed from the skul .

"This is a VP shunt. In the living patient you would have been able to feel the bottom tube running under the skin that overlies the ribs. That part of the device is missing."

I waited for her to go on.

"The peritoneal cavity is large and can usual y handle any amount of fluid delivered by the shunt. Another advantage of draining into the abdomen is that the rhythmic contractions of the intestinal organs move the tip of the catheter around. That motion prevents its becoming blocked or sequestered in scar tissue.

"When do these things go in?"

"As soon as hydrocephalus is diagnosed. As much as thirty-six inches of tubing can be placed in the abdomen of a neonate. As the child grows, the tubing unwinds to accommodate the increased length of the torso."

"I found a smal hole in the skul , near the parieto-temporal junction."

"That's a burr hole. It's dril ed during surgery to insert the upper end of the shunt into the brain. They're usual y made behind the hairline, either at the top of the head, behind the ear, or in the back."

Russel 's eyes flicked to a round metal clock on her desk, then back to mine. I was anxious to learn what difficulties might be caused by hydrocephaly, but knew the woman's time was limited. That research would be up to me.

I gathered my jacket and she returned the shunt to its jar, curling the paper and al owing the device to slide gently into place. We rose simultaneously and I thanked her for her help.

"Do you have any idea who your young lady is?" she asked.

"Not yet."

"Would you like me to send you some reading material on hydrocephalus? There are problems associated with the condition that you might find helpful."

"Yes, very much. Thank you."

Chapter 12