A hydrocephalus shunt is a medical device that some physicians use to treat patients with hydrocephalus. People with hydrocephalus, also known as water on the brain, typically have an accumulation of cerebrospinal fluid inside the skull that causes the brain to swell. Patients with this disorder may use a hydrocephalus shunt to drain cerebrospinal fluid away from the brain. Cerebrospinal fluid supplies the brain with important nutrients and removes waste products. Many people with hydrocephalus have a blockage in the normal flow of this fluid or excessive production of the fluid.
In most cases, a hydrocephalus shunt consists of a shunt catheter, a valve and a reservoir. The hydrocephalus shunt catheter is a narrow tube that is typically implanted in an area of the brain above a blockage. A catheter is usually connected to a valve that is set to control the rate at which the shunt withdraws fluid from the brain. Fluid in the shunt is normally stored in a reservoir before it is released in another part of the body, usually into the abdomen, lung cavity or heart atria. A fixed hydrocephalus shunt is typically set at one flow rate, and a programmable shunt usually allows a physician to change the rate of fluid flow with a magnetic device during an office visit.
Surgical placement of a hydrocephalus shunt may cause some complications. In some cases, a blockage can form in an implanted shunt and may cause vomiting or headaches. Physicians are able to eliminate a blockage without replacing a shunt in some instances. Other possible shunt placement complications can include tube separation, kinking or infections such as encephalitis or meningitis. Nerve damage, cognitive impairment and physical disabilities may occur in some hydrocephalus patients with shunts.
Hydrocephalus in unborn babies may be caused by infections that occur during pregnancy or a birth defect such as myelomeningocele, a condition that generally results in a partial opening of the spinal column. Young children can develop hydrocephalus from central nervous system infections, brain or spinal cord tumors and brain injuries. Some adults may develop hydrocephalus, although it is generally more common in children.
Infants with hydrocephalus have a downward gaze, vomiting or irritability in many cases. The soft spot on an infant’s head may be larger than normal, and unusual sleepiness may occur with this condition. In some cases, children with this medical disorder experience changes in personality, headaches or loss of bladder control. Uncontrolled eye movements, shrill crying and loss of coordination as well as slow physical growth have been reported in some children with hydrocephalus.
In addition to a shunt, some patients with hydrocephalus may receive antibiotics to fight an infection. Doctors may remove a shunt in some cases of severe infections. Other treatments for this disorder include cauterizing or burning away areas of the brain that produce excessive amounts of cerebrospinal fluid. Physicians typically monitor symptoms as well as physical and mental development of hydrocephalus patients during periodic medical examinations.