This page is intended to provide general information about NPH as well as its treatment at Barrow Neurological Institute. This information is not intended to be used for the treatment of an emergent condition requiring immediate attention.
1. What is normal pressure hydrocephalus (NPH)?
NPH develops slowly over time and is primarily restricted to older adults. It is an accumulation of cerebrospinal fluid (CSF) within cavities, called ventricles, inside the brain. Every day, the average adult produces about one pint of CSF, which cushions the brain from injury and carries nutrients to and waste products away from the brain. In NPH, CSF is produced in normal amounts, but it is prevented from being normally re-absorbed.
The ventricles of the brain enlarge to accommodate the increased volume of CSF so its pressure, as measured by lumbar puncture (spinal tap), remains normal. Brain tissue is damaged or destroyed by compression from the fluid-filled ventricles. If a cause is identifiable and can be corrected, the symptoms may reverse or at least stop getting worse. If there is no is identifiable cause, the disorder is often progressive.
2. What are the symptoms?
Because these same symptoms can characterize the aging process, NPH is greatly underdiagnosed or misdiagnosed as other conditions common among the elderly such as Parkinson's or Alzheimer's disease. Even when NPH is diagnosed, neurologists and neurosurgeons may hesitate to begin treatment because traditional approaches to management with fixed-flow shunts have been associated with high rates of serious complications. As a result, individuals with NPH can lose many years of what otherwise might have been an active, vigorous retirement. In the United States alone, this menacing disease afflicts 300,000 to 400,000 people over the age of 65 years.
Gait disturbances. These range from mild imbalance to the inability to stand or walk. Gait may be widespread, short, slow and shuffling, or individuals may have trouble picking up their feet. Gait disturbance is often the most pronounced symptom and the first to become apparent.
Mild dementia. Loss of interest in daily activities, forgetfulness, difficulty dealing with routine tasks, and short-term memory loss are characteristic.
Impairment in bladder control. Severity ranges from urinary frequency and urgency in mild cases to complete loss of bladder control (urinary incontinence) in more severe cases.
3. What are the causes?
The cause of most cases of NPH is unknown. The normal process of aging can lead to softening of the brain (decrease in brain turgor). This chronic compensated condition likely leads to decompensation and symptomatic deterioration. In some cases, NPH can develop as the result of head injury, cranial surgery, subarachnoid hemorrhage, meningitis, tumors, cysts, subdural hematomas, bleeding during surgery, and infections.
4. How is NPH diagnosed?
Once symptoms of gait disturbance, mild dementia, or problems with bladder control are identified and NPH is suspected, a physician may recommend one or more additional tests. At this point in the diagnostic process, it is important that a neurologist and a neurosurgeon are identified, along with the primary care physician. Their involvement from the diagnostic stage onward is helpful not only in interpreting test results, but also in discussing surgery, follow-up care, and expectations of surgery. The decision to order a given test may depend on the specific clinical situation. Please click here for additional details concerning Diagnostic Procedures.
5. Can NPH be prevented?
Although there is no known way to prevent NPH establishing a healthy lifestyle, including maintaining an appropriate weight, not smoking, and regular exercise, may help avoid conditions such as high blood pressure, heart disease, diabetes, and stroke that might contribute to NPH.
6. How is NPH treated?
Although NPH cannot be cured, it can often be controlled. Fortunately, NPH can often be treated successfully with a special shunt that drains excess CSF away from the brain to another part of the body, usually the abdominal cavity, where it can be absorbed. The shunt most often placed is the ventriculoperitoneal shunt. Lumboperitoneal shunts and ventriculoatrial shunts also may be used in certain situations. There are a variety of shunt types, including differential pressure valves, flow-regulated valves, anti-siphon devices and programmable valves.
A shunt operation is not a cure. It does not treat the underlying cause of NPH. It can, however, relieve the symptoms. The shunt remains in place indefinitely. If properly implanted, a shunt is seldom obvious to other people. The earlier that NPH is diagnosed, the better are the chances that surgery will help. In general, people with milder symptoms have better outcomes after this surgery than patients with severe symptoms. Click here for additional details about Treatment.
7. What is the prognosis for NPH treatment?
Although shunt operations do not work for everyone with NPH, many people experience mild to dramatic relief of their symptoms. The symptoms, including gait disturbance, mild dementia, and incontinence, may resolve within days to weeks of a shunt procedure. However, some patients may require significantly more time to improve. There is no way to predict who will benefit and who will not. Neither is possible to predict how long the improvement will last. The course of clinical improvement varies for each patient. Some patients seem to reach a plateau, while others improve for months but then seem to decline again. Typically, patients experience worsening symptoms immediately after surgery and then gradually improve. Unfortunately, there are no guarantees. The most common complications of this procedure include infection, shunt malfunction, and bleeding. If a patient's immediate success is followed by a relapse of symptoms reprogramming of the shunt may be considered.
8. Where do I start to find out if I or a loved one has NPH?
Please call the Barrow ResourceLink at 1-800-227-7691 and ask to be enrolled in the NPH Program. They will refer the patient to the Normal Pressure Hydrocephalus Clinic to begin the screening process. Once the necessary tests are completed, recommendations for a treatment plan will be communicated to the patient.