Here’s what to be aware of when it comes to potential magnetic interference for your patients who have VP shunts.
Hydrocephalus is the medical term for a condition that is commonly called “water on the brain.” It is a combination of the Greek word “hydro,” which means water and “cephal” which means head. But the liquid involved in hydrocephalus is not really water at all, it is cerebrospinal fluid or CSF.
Hydrocephalus occurs when the delicate balance of CSF production and absorption is disrupted, and CSF builds up within cavities called ventricles inside the brain. This build-up of CSF causes the brain to swell, and for pressure to increase inside the skull, resulting in potential neuron damage.
What Are the Different Types of Hydrocephalus?
Congenital hydrocephalus is caused by a brain malformation or birth defect that causes excessive CSF to accumulate in brain cavities, called the subarachnoid space. Congenital hydrocephalus is often diagnosed before birth through routine ultrasound.
Acquired hydrocephalus develops after birth as a result of a neurological condition or injury such as hemorrhage, meningitis, head trauma, tumors and cysts.
Communicating hydrocephalus describes when the flow of CSF is blocked after it exits the ventricles but can still flow between the ventricles, which remain open.
Non-communicating hydrocephalus, also called obstructive hydrocephalus, occurs when the flow of CSF is blocked between structures of the brain. This type of hydrocephalus is often caused by a condition known as aqueductal stenosis, which describes a narrowing of the Sylvius, a small passage between the ventricles in the middle of the brain.
Normal pressure hydrocephalus (NPH) is a form of communicating hydrocephalus that is most common among people over the age of 55. This type of hydrocephalus can be caused by bleeding in the brain’s CSF, head trauma, infection, tumor, or a complication of surgery. Yet many people develop NPH when none of these factors are present. NPH causes problems with gait, bladder control, and cognitive function – symptoms often mistaken for Alzheimer’s disease.
How Many People Have Hydrocephalus?
When cases of spina bifida are included, congenital hydrocephalus occurs in as many as 2 to 5 births per 1,000 births. The number of people with acquired hydrocephalus is not known.
The Hydrocephalus Associations estimates that 1 million American have some type of hydrocephalus. Furthermore, the National Hydrocephalus Foundation found that there are approximately 75,000 discharges a year from U.S. hospitals with a diagnosis of hydrocephalus.
How Is Hydrocephalus Diagnosed?
To diagnose hydrocephalus before birth, healthcare professionals usually perform ultrasound examinations of pregnant women to see how the fetus is developing. During an ultrasound, the healthcare professional looks at many things, including the developing brain and spine of the fetus. Hydrocephalus can be diagnosed as early as 13 weeks gestation. Although abnormal changes in the ventricles of the brain are easier to see at 20 to 24 weeks gestation.
To diagnose hydrocephalus acquired later in life, patients will undergo a neurological exam as well as imaging techniques such as a CT scan or MRI – and on occasion, a pressure-monitoring system. In some case, an MRI can show where the CSF blockage has occurred and can help determine the most appropriate treatment.
How Is Hydrocephalus Treated?
Although hydrocephalus cannot be cured or prevented, effective treatments are available to help people with hydrocephalus live happy, productive and fulfilling lives. One effective treatment for hydrocephalus is the surgical placement of a shunt. A shunt is a one-way valve that allows excess CSF that has built-up inside the brain to drain out into another part of the body, such as the abdomen or heart. To drain excess CSF, the proximal shunt catheter is inserted into an opening inside the brain called a ventricle.
Another treatment option is endoscopic third ventriculostomy (ETV), sometimes referred to as a “3V” or “third-vent,” to improve the flow of CSF out of the brain. ETV is performed by making a small hole in one of the ventricles in the brain where CSF is produced, so the CSF can flow more easily and be absorbed. Only select patients may be a good candidate for ETV treatment and the procedure is typically performed in children over the age of two.
In some cases when the patients is under two years old, ETV may be performed in addition to a procedure called choroid plexus cauterization (CPC). In this treatment, a neurosurgeon uses a device to burn or cauterize the choroid plexus, a vascular tissue within the ventricles of the brain that is the source of CSF production.
Are There Drug Treatments for Hydrocephalus?
Although there are currently no drugs for the treatment of hydrocephalus, some medications have been used to help alleviate certain symptoms associated to hydrocephalus. You should discuss this option with your physician.
Who Should I Contact to Help Me Further?
Neurologists and neurosurgeons are highly qualified to answer your questions about hydrocephalus. You can also get helpful information from support groups and organizations such as the Hydrocephalus Association, which provides guidance on the types of treatments available and how to prepare for brain surgery as well as for any complications that arise from treatment.