About shunt systems
Shunt systems come in a variety of models but always have two similar components: a catheter, the tubing that transports and diverts the CSF from the ventricles to either the abdominal cavity or right atrium, and a valve that regulates the pressure or flow of CSF from the ventricles. The catheter component of the shunt system is divided into proximal and distal limbs. The proximal limb is inserted into the ventricles (central fluid cavities of the brain) and the distal limb into the abdominal cavity (in the case of a ventriculo-peritoneal shunt). Other sites may be used for implantation of the distal catheter limb. The interposed valve serves to regulate CSF flow and may be fixed pressure or programmable. Surgeons have the option of implanting either type of valve. Multiple factors may influence their decision.
Many shunt systems also have a flexible flushing chamber called a reservoir. The reservoir may be housed within the shunt system or added as a component along with the shunt system. The reservoir may be accessed percutaneously (through the skin, typically with a fine needle) by the surgeon. This allows for sampling of CSF to rule out infection and allows for assessment of shunt patency (to rule out blockage or malfunction).
Shunt systems are completely INTERNAL to the body. They remain indefinitely unless there is need for removal (in the event of infection) or revision.
The Triad of NPH
- Gait ataxia: the primary symptom of NPH; an imbalanced, wide-based walk or “shuffle.” Patients claim that their feet feel “stuck to the ground.” Classically the gait is characterized as “magnetic.”
- Urinary incontinence: an inability to control one’s urine
- Dementia: cognitive decline with associated memory loss