Normal Pressure Hydrocephalus (NPH) is a neurological disorder characterized by an excessive accumulation of cerebral spinal fluid (CSF) in the ventricles of the brain. CSF is always present, circulating critical nutrients to the brain and nervous system, and acting as a protective cushion. When the flow of CSF is interrupted in some way, the fluid can build-up, stretching the brain tissue and resulting in such symptoms as difficulty walking, impaired bladder control, and mild dementia. NPH is often misdiagnosed as Alzheimer's or Parkinson's disease. The cause of most NPH cases is unknown (idiopathic).
Normal Pressure Hydrocephalus affects more than 1 in every 200 adults over the age of 55. An estimated 5-10% of individuals showing symptoms of dementia actually have NPH. The exact cause can rarely be determined – which is why NPH so often goes undiagnosed – but once identified, treatment can potentially lead to a return to normal levels of CSF in the brain. It is estimated that ¼ of a million North Americans may actually have Normal Pressure Hydrocephalus.
It is a difficult condition to diagnose but, once diagnosed, is readily treatable and its symptoms can often be reversed. NPH is not an inherited or genetic condition. There is no indication that you can develop NPH if someone in your family or extended family is affected.
|Symptoms of NPH||Diagnosis of NPH||Treatment of NPH||How SB&H Can Help|
Normal Pressure Hydrocephalus is characterized by 3 primary symptoms, which typically onset gradually over months to years:
These three primary symptoms are not always present at the same time. Difficulty walking is usually the first symptom to appear. This is different from Parkinson’s Disease where involuntary muscle tremors occur first and Alzheimer’s where memory problems are the earliest symptom. Other symptoms can include difficulties with balance, headaches, and fatigue brought on by little or no exercise.
Gait disturbances range in severity, from mild imbalance to the inability to stand or walk at all – people will often describe feeling as though their feet are “stuck to the floor.” Many people with NPH have a gait that is wide-based, with steps that are short and slow. People may have trouble picking up their feet, making it difficult to go up stairs and curbs, and often resulting in falls. Gait disturbance is typically the most pronounced symptom of NPH and the first to become apparent.
Mild dementia (impaired mental functioning)
People with NPH typically experience mild dementia, which can be described as forgetfulness, a loss of interest in daily activities, difficulty accomplishing routine tasks, and impaired short-term memory. Behavioural changes can accompany the problems with memory that are often experienced. People do not usually lose language skills or experience any changes in their vision or other senses. Not everyone will have an obvious cognitive impairment and some people may have dementia but deny that there are any problems.
Impaired bladder control
Bladder control issues are usually characterized by urinary frequency, the need to urinate more often than usual (often every 1-2 hrs), and urgency, an immediate and strong sensation of the need to urinate. In more severe cases, a complete loss of bladder control (urinary incontinence) can occur. In very rare cases, fecal (bowel) incontinence may occur. Some people never display signs of bladder impairment. In others, the problem can be made worse by a slow gait that makes reaching the bathroom in time more difficult.
Once a physician suspects NPH, testing is usually carried out to confirm the diagnosis and assess the individual’s suitability for treatment. It is important that a neurosurgeon or neurologist become part of the medical team at this point, to interpret test results and discuss surgery and its risks. The medical team will consider the pattern and severity of impairments, along with the results of other tests, in differentiating NPH from other conditions such as Alzheimer’s or Parkinson’s disease or other forms of hydrocephalus.
Physical and neurological examinations will be used to evaluate the symptoms. There will be discussion and observation of walking to determine the extent and type of gait disturbance. Asking questions or administering neuropsychological evaluation will test cognition. Areas of examination include attention span, reaction time, memory, reasoning, language, and emotional state. There will be verbal assessment of urinary urgency and frequency or incontinence.
Diagnostic imaging such as an MRI or CT scan will be performed to examine the brain and detect enlarged ventricles. Other testing could include CSF tests such as lumbar puncture (spinal tap), external lumbar drainage, measurement of CSF outflow resistance and intracranial pressure.
Is It Really Alzheimer’s?
NPH is commonly misdiagnosed as Alzheimer’s Disease. ABC News produced an excellent piece on this topic. View it at http://abcnews.go.com/GMA/OnCall/story?id=6191680&page=1
The Hydrocephalus Association in the United States has posted a new item that you may find of interest, 'If It's Not Alzheimer's Disease or Parkinson's Disease, It May Be NPH'
The following questions are designed to screen for the symptoms of Normal Pressure Hydrocephalus and help doctors in identifying the disorder. If you experience any symptoms of NPH, we encourage you to meet with your doctor because only a doctor can make a diagnosis. You may find it helpful to print this page and bring it with you to the doctor’s office if you decide to make an appointment.
1. My feet feel stuck to the floor when I walk. ___ Yes ___ No
2. I have trouble keeping my balance when walking or turning. ___ Yes ___ No
3. I have experienced sudden falls without the loss of consciousness ___ Yes ___ No
4. I have difficulty maintaining attention. ___ Yes ___ No
5. I have trouble remembering things. ___ Yes ___ No
6. I have experienced sudden urgency in urinating. ___ Yes ___ No
7. I have had urinary accidents. ___ Yes ___ No
Although NPH is a chronic condition, with early detection, effective treatment and appropriate interventional services, symptom reversal and a return to a high quality of life is increasingly possible. The future for individuals with NPH is promising.
How is NPH treated?
The seriousness of NPH symptoms may vary from day to day, but the progression is not likely to stop on its own. The most common, and usually the only available, treatment for NPH is surgical implantation of a shunt.
What is a shunt?
Shunts are devices used to drain extra cerebrospinal fluid (CSF) from the ventricles of the brain to another part of the body where it is reabsorbed. They have two major components: a catheter, the tubing that transports and diverts the CSF from the ventricles to either the abdominal cavity or right atrium, and a valve that regulates the pressure or flow of CSF. Valves are manufactured to operate at a specific pressure range. A surgeon chooses a pressure range for the shunt based on experience and the needs of the individual with hydrocephalus.
Many shunt systems also have a flexible flushing chamber called a reservoir. The reservoir permits the doctor to remove samples of CSF for testing, using a needle and syringe. The doctor also may inject fluid into the shunt system to test for flow; to be sure the system is functioning.
Appropriateness of shunt surgery
Many tests and evaluation criteria are considered but unfortunately, no single factor is reliable in predicting success from shunt implantation. However, the chance of a more complete recovery depends on the following factors:
onset of gait disturbances is the first and most prominent symptom
monitoring of intracranial pressure or spinal fluid pressure shows an abnormal range or pattern of spinal fluid pressure or an elevated CSF outflow resistance
removal of spinal fluid gives dramatic temporary relief of symptoms
minimal evidence of a disease of the small blood vessels that nourish the brain
Many people with NPH have additional medical or neurological problems. It is important to discuss with the medical team what outcomes can be expected in regaining motor skills or mental functioning. It is also important to understand that shunting may improve all or none of the hydrocephalus symptoms. While everyone hopes for a full recovery, it is not always seen. Many individuals are satisfied with reduced levels of disability or dependence, or the prevention of further neurological deterioration.
Some individuals with enlarged ventricles show no symptoms and no neurological impairment, even when medically evaluated. This is often called “compensated hydrocephalus.” In such circumstances, there are no benefits that would offset the potential risks of treatment.
Outcomes of surgery
There is currently no way to predict how quickly or to what extent shunt implantation will relieve symptoms. Gait disturbance, mild dementia and bladder control problems may improve within days of surgery, or it may take months. There is also no way to predict how long these improvements may last. Some individuals reach a plateau, while others may improve for months and then decline again. Potential risks and complications of surgery may include obstruction and malfunction of the shunt, infection and development of a clot.
Shunt success may also be affected by the presence of other neurological or medical conditions. For example, high blood pressure on the brain can cause multiple tiny strokes in the same area of the brain affected by hydrocephalus, causing virtually the same symptoms.
If there is recurrence of symptoms, the individual should consult a member of their medical team to ensure that there is no malfunction of the shunt, or other complications.
The Association is addressing the issues faced by individuals and caregivers coping with Normal Pressure Hydrocephalus. SB&H provides information about NPH as well as resources, activities and support groups to help effectively cope with the ongoing challenges that NPH presents.
Awareness & Education
SB&H is conducting an awareness and education campaign “Bridging the Gap” to inform the public and health care professionals about this emerging condition.
To receive a free information kit on NPH or if you have any questions, please email email@example.com or call SB&H at 800-387-1575.
Since 2002, adults with hydrocephalus have been able to take part in the Adults Living with Hydrocephalus Support Group.
The Association is encouraging, supporting and funding research into early diagnosis, technologies that make treatment more effective and quality of life concerns for those affected by NPH.
SB&H is a founding member of Neurological Health Charities Canada (NHCC), a collective of organizations that represent people with chronic brain diseases, disorders and injuries in Canada. The NHCC has successfully persuaded the Federal Government to invest $15 million in a national research study to build a better understanding of the incidence, prevalence, impact, risk factors and co-morbidities of neurological conditions, which includes NPH.
The NHCC is working with the Ontario Ministry of Health and Long-Term Care to identify common issues facing Ontarians with neurological conditions. Their ultimate goal is to develop a neurological strategy for Ontario that will provide:
A reduction in the impact of disability enabling individuals, including those with NPH, to participate more fully in life,
Improved access to services and supports, and,
Greater equity in the provision of these services and supports
You can keep up with the work of the NHCC by visiting their website at www.mybrainmatters.ca where we encourage you to fill out and submit a registration form. After your registration is processed, you will receive email updates and news on the latest work of the NHCC as we work with government toward the development of the Neurological Strategy.