Hydrocephalus in Adults

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    Hydrocephalus is an abnormal accumulation of fluid in cavities called ventricles inside the brain. Anyone at any age can be diagnosed with hydrocephalus. Vastly different from hydrocephalus diagnosed in infancy and early childhood, or adult-onset normal pressure hydrocephalus (NPH) found in older adults (typically age 60 and older), hydrocephalus in young and middle-aged adults is a unique and often confusing condition.

    This age group presents a host of challenges and opportunities for patients and medical professionals alike. The challenge goes far beyond routine or specialized medical care, encompassing psychosocial, emotional, and occupational issues.

    For more detailed information on hydrocephalus, visit About Hydrocephalus and Cerebrospinal Fluid Dynamics Relevant to Hydrocephalus.


    Hydrocephalus in Adults: Types and Causes

    There are four categories of adults living with hydrocephalus.

    Adults newly diagnosed with congenital hydrocephalus

    A neurosurgeon tells you that you have hydrocephalus and that you have had it since birth, but this is the first time you are ever hearing about the condition. This is not an unfamiliar story. Hydrocephalus that is present at birth is referred to as congenital hydrocephalus. Sometimes it does not cause symptoms until adolescence or adulthood even though it is a condition that existed at birth. It is unclear why hydrocephalus can remain dormant for many years only to cause symptoms later in life. Either the fluid slowly accumulates to a point where it results in brain dysfunction or chronic static enlargement of the fluid spaces causes a subtle ongoing injury that eventually erodes the brain’s ability to compensate. Such cases are sometimes classified as decompensated congenital hydrocephalus.

    At times asymptomatic hydrocephalus is identified on a head CT or MRI that was obtained for completely unrelated neurologic symptoms. For example, clinicians are often surprised to see hydrocephalus on brain imaging studies performed following mild head trauma. In these cases, the trauma had nothing to do with the hydrocephalus which would have been present all along. Likewise, many patients undergo brain imaging for headaches or dizziness when such symptoms are caused by unrelated problems such as migraine or inner ear disorders. Again, the hydrocephalus would have been identified had the scan been performed prior to the onset of the symptoms.

    Congenital hydrocephalus is caused by a complex interaction of genetic and environmental factors during fetal development. The most common causes of congenital hydrocephalus are:

    • Spina bifida
    • Aqueductal stenosis
    • Brain malformations

    Adults who acquire hydrocephalus

    Acquired hydrocephalus is the form of hydrocephalus that develops any time after birth. Both children and adults can be diagnosed with acquired hydrocephalus. The most common causes are:

    • Head injuries
    • Brain tumors
    • Intraventricular hemorrhage (brain bleed)
    • Meningitis or other infection of the brain or spinal cord

    Adults who are diagnosed and treated in childhood (Transitioning(ed) Adults)

    Prior to the shunt being available commercially to treat hydrocephalus, there was no widespread treatment for patients and poor long-term outcomes. Now children with the condition are growing up and transitioning into adulthood and adult medical care. For more detailed information, visit Life Transitions.

    Adults diagnosed over the age of 60

    Normal pressure hydrocephalus (NPH) occurs in older adults, typically diagnosed in individuals 60 and older. Normal pressure hydrocephalus is an accumulation of CSF that causes the ventricles in the brain to become enlarged, but there is little or no increase in the pressure within the ventricles. However, in some NPH patients CSF pressure does fluctuate from high to normal to low when monitored. In most cases of NPH, the cause of blockage to the CSF absorptive pathways is unclear; these cases are referred to as idiopathic NPH (iNPH). Secondary NPH is the term used to denote cases where a cause is apparent (e.g. trauma, tumor, stroke or meningitis).

    There are other classifications of hydrocephalus that you might hear when talking to your doctor, particularly around the time of diagnosis. These can include:

    For more detailed information, visit Types and Causes.


    Symptoms of Hydrocephalus in Young Adults

    The symptoms of hydrocephalus in young adults are similar in some ways to those of NPH in the elderly, but are often much more subtle. And yet they can have a most profound effect on patients’ lives, in the hardest cases rendering adults unable to work or to have difficulty functioning in day-to-day life.

    Sometimes, symptoms are disregarded as manifestations of a mid-life crisis or other psychological and emotional issues. Additionally, as symptoms worsen and the condition goes undiagnosed, one’s ability to function at home and work can be affected, and relationships and employment can be compromised.

    Symptoms reported include, but are not limited to, vision problems, balance and coordination issues, disturbances in gait, fatigue, chronic headaches, vertigo, syncope (fainting), nausea, and short-term memory issues.

    The degree of symptoms and their resultant effect varies widely among patients. If symptoms have been present for years, the patient may be more seriously disabled. Early diagnosis can be a factor in the successful resolution of symptoms.

    Nevertheless, as mentioned earlier, because hydrocephalus can be entirely asymptomatic, it is important to recognize that many patients with these symptoms may be suffering from other unrelated neurologic and psychiatric problems. Just observing hydrocephalus on a brain scan does not “guarantee” that it is a relevant diagnosis.


    How is Hydrocephalus Diagnosed in Young Adults?

    A diagnosis is made by using brain imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and through clinical neurological evaluation during a doctor visit. More tests are often performed in adults in order to diagnose the condition. These tests may include lumbar puncture, continuous lumbar CSF drainage, intracranial pressure (ICP) monitoring, measurement of cerebrospinal fluid outflow resistance, or isotope cisternography. Neuropsychological evaluation may also be recommended. The decision to order a particular test may depend on the specific clinical situation, as well as the preference and experience of the medical team.

    Not all of the tests listed are required in order to make a diagnosis.

    Computed tomography (CT scan) is a reliable procedure for diagnosing and assisting in the management of hydrocephalus. It is a sophisticated technique in which x-ray beams are passed through a patient’s body and pictures of the internal structures, in this case, the brain, are made by the computer.

    Unexpected enlargement of the ventricles is often the first clue that hydrocephalus in an adult may be present, but this finding alone is usually not a sufficient reason to proceed to surgical therapy. It is important to remember that hydrocephalus can be compensated (non-progressing) or uncompensated (progressing), and further testing is often needed. It is potentially harmful to put a shunt into a person with compensated hydrocephalus, just as it is potentially harmful not to put a shunt into a person with decompensated hydrocephalus.

    Magnetic Resonance Imaging (MRI), like the CT scan, is a diagnostic technique that produces images of the brain—but unlike CT scanning, MRI does not use x-rays/radiation. Instead, MRI uses radio signals and a very powerful magnet to scan the patient’s body, and the signals are then formed into pictures by a computer. MRI is a painless procedure and has no known side effects. There are two types of MRI scans: The Single Shot Fast Spin Echo (also called a ‘quick brain MRI), which takes about three minutes and rarely requires sedation, is used to assess ventricular size. The full MRI, which takes 30 to 60 minutes and may require sedation for those prone to claustrophobia or anxiety, shows more minute details.

    The radiologist will review the scans, write a report, and send the report on to the doctor.

    It is sometimes necessary to perform an MRI with and without contrast enhancement. An MRI with the addition of a chemical agent enhances and improves the quality of the MRI image, allowing the doctor to look for subtle signs of tumor or chronic infection which can cause adult-onset hydrocephalus and which may require additional treatment besides shunt surgery. Prior to the MRI, a doctor or technician will inject the dye agent either directly into your arm or through an IV. The MRI will then proceed as normal.

    Lumbar Puncture, or spinal tap, allows an estimation of CSF pressure and analysis of the fluid. Under local anesthetic, a thin needle is passed into the spinal fluid space of the low back. Removal of around 50 cc of CSF is done to see if symptoms are temporarily relieved. If the removal of CSF dramatically improves symptoms, even temporarily, then surgical treatment is likely to be successful. The absence of improvement following a lumbar puncture, however, does not eliminate the possibility of improvement with shunt surgery. It is well recognized that many patients who experience little or no improvement after the test may still improve with a shunt.

    This test is extremely important if the cause of the hydrocephalus is not obvious. Occult infections or tumors with CSF spread may be found from culturing and analyzing the CSF for tuberculosis or fungi.

    External lumbar drainage, also called lumbar catheter insertion or continuous lumbar drainage, is a variation of the lumbar puncture. A spinal needle is inserted in the spinal fluid space of the low back, then a thin, flexible tube (catheter) is passed into the spinal fluid and the needle is removed. The lumbar catheter allows for continuous and more accurate recording of spinal fluid pressure, or for continuous removal of spinal fluid over several days. External lumbar drainage is a test that can emulate the physiologic effect of a shunt operation to imitate the effect that a shunt would have. Patients who respond dramatically to such spinal fluid drainage are likely to respond to shunt surgery. Nevertheless, a small proportion of patients who do not improve with lumbar drainage can still benefit from shunt surgery. Lumbar catheter insertion requires hospitalization.

    Intracranial Pressure Monitoring (ICP) is a diagnostic test that helps your doctors determine if high or low CSF pressure is causing your symptoms. ICP monitoring requires admission to the hospital. Your surgeon will make a small hole called a burrhole in the skull and a small pressure monitor is inserted into the brain or ventricles to measure the ICP. The test measures the pressure in your head directly using a small pressure-sensitive probe that is inserted through the skull.

    Isotopic Cisternography involves having a radioactive isotope injected into the lumbar subarachnoid space (lower back) through a spinal tap. This allows the absorption of CSF to be evaluated over a period of time (up to 96 hours) by periodic scanning. This will determine whether the isotope is being absorbed over the surface of the brain or remains trapped inside the ventricles. Isotopic cisternography involves lumbar puncture and is considerably more involved than either the CT or MRI. This test has become less popular because a “positive” cisternogram result does not reliably predict whether a patient will respond to shunt surgery. Its utility in hydrocephalus in adults is not known.

    Neuropsychological Testing
    Neuropsychology is the study of brain-behavior relationships. When a patient’s primary problems include thinking, emotion, and behavior, a neuropsychological evaluation can be an important complement to clinical work in making a diagnosis. An evaluation can also help family members and physicians understand the impact of hydrocephalus on a patient’s everyday function.

    A neuropsychological assessment typically includes a thorough interview with the patient and one or more family members, as well as a close review of medical records and studies. A series of tests are administered to assess various aspects of cognitive function, including attention, memory, language, visual-spatial ability, and executive function (the ability to reason, plan, and modulate behavior). The ultimate goal is to understand how changes in brain structure and function are affecting the patient’s behavior.

    In the case of hydrocephalus in adults, neuropsychological testing can help serve as a tool to determine whether or not a patient would benefit from immediate surgical intervention or should simply be monitored for a longer period. Furthermore, the pattern of neuropsychologic impairment can help determine if a patient’s cognitive symptoms are consistent with hydrocephalus or are more likely due to another co-existing neurologic condition.

    At this point in the diagnostic process, it is important that a neurologist and a neurosurgeon become part of your medical team, along with your primary care physician. Their involvement from the diagnostic stage onward is helpful not only in interpreting test results and selecting likely candidates for shunting but also in discussing the actual surgery and follow-up care, as well as expectations of surgery.


    How is Hydrocephalus in Young Adults Treated?

    While there is currently no known way to prevent or cure hydrocephalus, there are three life-saving treatment options that require brain surgery.

    The most common treatment for hydrocephalus is a medical device called a shunt, a flexible tube, which is placed in the ventricular system of the brain and connected to a valve. A small hole called a burrhole is made in the skull and the tube is gently guided through the brain to the fluid-filled ventricles. The tube is left in the ventricle to take the cerebrospinal fluid (CSF) to another region of the body, most often the abdominal cavity, or heart, where it can be absorbed. The tube from the brain is connected to a valve that regulates how much fluid leaves the brain.

    A second surgical treatment option is called an Endoscopic Third Ventriculostomy (ETV). This is typically used for children over the age of 2 with non-communicating hydrocephalus; hydrocephalus caused by a blockage in the brain like aqueductal stenosis. Similar to the shunt surgery, a small hole is made in the skull and then an endoscope is gently guided through the brain into one of the lateral ventricles. With the use of a camera, the endoscope then passes down into the third ventricle and punctures the membrane on the floor of the third ventricle. This creates an alternative pathway for CSF to flow around the brain. A shunt is not needed. ETV is sometimes considered an option for the treatment of adults with decompensated congenital hydrocephalus.

    Not everyone is a candidate for ETV treatment. Learn more, watch our video.

    The third treatment option involves an ETV with the addition of a procedure called choroid plexus cauterization (CPC). This treatment is primarily used in children under 2. Once inside the brain, the neurosurgeon uses a device to burn or cauterize choroid plexus tissue to reduce the amount of fluid being introduced into the ventricles. The choroid plexus is vascular tissue within the ventricles of the brain and is the source of CSF production. The fluid then passes normally through the opening made during the ETV and into the ventricular space surrounding the surface of the brain. Not everyone is a candidate for ETV/CPC treatment.

    With early detection and effective treatment and appropriate interventional services, the outlook for adults with hydrocephalus is promising.

    To find an adult neurosurgeon, visit our Physician Directory.


    Management of Hydrocephalus in Young Adults

    Investments in research and advances in technology, as well as diagnostic and treatment protocols, are helping more and more people with hydrocephalus to lead full and active lives. But it is important to understand that life with a shunt or ETV does require you to always be well informed and vigilant about complications. While some people can go 20 years or more without a complication, with a complex condition like hydrocephalus, things can change quickly therefore it’s critical to be prepared.

    Complications of a Shunt and an ETV

    When things are going well, it’s easy to put the concerns about hydrocephalus and the complications that come with it out of your mind. However, shunts can malfunction or become infected and this requires a shunt revision, which requires brain surgery. An ETV can close at any time and put an individual in an emergency situation. It is critical to understand the signs and symptoms of shunt failure or the closure of an ETV.

    Seeking immediate medical attention can identify a resolvable complication and enable you or your family member to avoid brain damage or even death.


    What is the Prognosis for Adults with Hydrocephalus?

    In many cases, prompt treatment of hydrocephalus in adults can reverse many of the symptoms, restoring much cognitive and physical functioning. Many adults diagnosed with hydrocephalus lead full lives with proper management of the condition. However, it is a complex condition and the long-term effects of hydrocephalus can vary greatly from person to person. Prognosis is dependent on the cause, individual symptoms, timeliness of diagnosis, and patient’s responsiveness to treatment. Prognosis is also influenced by the presence of other neurologic disorders. For example, it is well appreciated that Alzheimer’s disease (AD) can co-exist with NPH in older patients and may be more relevant with respect to cognitive disability. Other forms of neuropathology such as stroke and neurodegenerative conditions that result in gait impairment can also be relevant factors. Over time, some of these diagnoses can “swamp” the effect of hydrocephalus causing symptoms to progress even when shunts are found to be operational.

    Some general problems we see across our patient population include but are not limited to headaches, chronic pain, and psychosocial, emotional, and occupational issues. It is also important to know that if left untreated, progressive symptoms can become quite disabling, leading to severe cognitive and physical decline. Complications due to hydrocephalus can sometimes be fatal. It appears that the length of time between the onset of symptoms and diagnosis is a factor in the success of treatment. Another, as yet unmeasurable, factor that affects the outcome of treatment is the extent of reversible versus irreversible brain injury caused by hydrocephalus. Treatment is most successful when little irreversible injury has occurred.

    You’re not alone. The journey with hydrocephalus can be challenging and unpredictable. We provide essential tools and resources that enable you to have more control of your life. There is a large community across the country that is engaged and connected through the Hydrocephalus Association ready to support you and your family. By staying well informed and planning appropriately, you or your loved one can realize their dreams of graduating college, pursuing and maintaining a career, getting married, having a family, and enjoying retirement.

    For more detailed information, visit Daily Life.


    Research and Hydrocephalus

    As the leading private funder of hydrocephalus research in the country, we are investing in research to improve outcomes, prevent the development of hydrocephalus, and, ultimately, find a cure. The Adult Hydrocephalus Clinical Research Network (AHCRN) is a network of hospitals that conduct clinical research on hydrocephalus to improve treatment for the adult forms of hydrocephalus, including transitional patients who were diagnosed as children, those who acquire hydrocephalus as adults, and patients with normal pressure hydrocephalus.

    You can be a part of research. Enroll in HAPPIER, the only hydrocephalus patient powered registry in the country, and help our doctors and scientists better serve you!

    The Hydrocephalus Association regularly supports our scientists and doctors by assisting in gathering data through surveys as well as through helping enroll patients in current research studies.


    Information you can trust! This article was produced by the Hydrocephalus Association, copyright 2021. We would like to thank James B. Golomb, MD for his valuable contribution and expert input.