Hydrocephalus is a condition characterized by the abnormal buildup of cerebrospinal fluid (CSF) within the brain’s ventricles. This excess fluid can cause the ventricles to widen, placing pressure on brain tissues. While there is currently no cure for hydrocephalus, it can be managed effectively with surgical intervention. The most common treatment involves the placement of a medical device known as a shunt, which helps to drain this accumulated fluid.
Understanding the Shunt System
A shunt is a flexible tube surgically placed to redirect excess cerebrospinal fluid from the brain for absorption elsewhere in the body. Most shunts consist of two catheters and a connecting valve, often with a reservoir. The proximal catheter is placed in a brain ventricle to collect fluid, connecting to a valve usually positioned under the scalp.
The valve regulates the amount, flow, and pressure of CSF leaving the brain, opening when intracranial pressure is too high. The distal catheter tunnels under the skin to an area like the abdomen, where fluid is naturally absorbed. Many shunts include a bulb-like reservoir, felt through the skin, allowing professionals to sample CSF, inject fluid, or measure pressure.
Types of Shunts
Shunts are categorized by where CSF is diverted. The most common is the ventriculoperitoneal (VP) shunt, draining fluid from brain ventricles into the abdominal peritoneal cavity. Another type is the ventriculoatrial (VA) shunt, directing fluid from the brain into the heart’s right atrium via a neck vein. Less common options include ventriculopleural (VPL) shunts, diverting fluid into the chest cavity, and lumboperitoneal (LP) shunts, draining from the spine to the abdomen.
Shunt valves come in fixed-pressure and adjustable-pressure types. Fixed-pressure valves are set at a specific pressure level during manufacturing. Adjustable-pressure (programmable) valves contain a magnet, allowing a neurosurgeon to non-invasively change settings after implantation using an external device. Newer adjustable valves may incorporate magnetic-resistant walls to prevent unintended changes from external magnetic fields like MRI machines.
Living with a Shunt
Individuals with a shunt can typically lead full and active lives with appropriate management. Regular medical follow-ups are important to ensure correct shunt function and monitor symptoms. These appointments often involve imaging studies to assess the shunt’s position and the size of the brain’s ventricles. While a shunt is generally designed to be a lifelong treatment, many individuals can participate in most daily activities, including school, work, and exercise.
Participation in contact sports may require careful consideration and discussion with a healthcare provider due to the potential for head trauma, which could damage the shunt. When traveling, it is advisable to carry medical identification that indicates the presence of a shunt, in case of an emergency. Additionally, individuals with adjustable-pressure shunts should be aware of strong magnetic fields, such as those from MRI machines, as they might alter the shunt’s settings, unless they have a magnet-resistant model. Prompt communication with the medical team about any concerns or changes in health status is always encouraged.
Recognizing Complications and Seeking Care
Despite their effectiveness, shunts can experience complications, most commonly malfunction and infection. Shunt malfunction occurs when the system stops draining fluid effectively, often due to a blockage, disconnection, or breakage of the tubing. Signs of a shunt malfunction can include symptoms similar to those of untreated hydrocephalus, such as worsening headaches, nausea, vomiting, and drowsiness or lethargy. Other indicators might include changes in vision, difficulty walking, or swelling along the shunt’s path.
Shunt infection is another serious complication, which can occur at any point after implantation, though it is more common shortly after surgery. Symptoms of an infection may include fever, redness or tenderness along the shunt’s tract, and general malaise. In some instances, fluid might leak from the surgical incision site. Over-drainage, where the shunt removes too much CSF, can also occur, potentially leading to severe headaches, nausea, and vomiting. This can cause the ventricles to collapse, risking tearing blood vessels and causing bleeding in the brain.
It is extremely important to recognize these signs and seek immediate medical attention if any complication is suspected. Delaying care can lead to worsening symptoms and potentially serious health consequences. Individuals with a shunt should have an emergency plan and know how to contact their neurosurgeon or a hospital equipped to handle shunt-related issues. Early detection and intervention are paramount for managing shunt complications and maintaining well-being.