Normal-pressure hydrocephalus consists of difficulty walking, urinary incontinence, and dementia due to an increase in the fluid that normally surrounds the brain.
Normally, the fluid that surrounds the brain and protects it from injury (cerebrospinal fluid) is continuously produced in the spaces within the brain (ventricles), circulates in and around the brain, and is reabsorbed. Normal-pressure hydrocephalus is thought to occur when this fluid is not reabsorbed normally, causing it to accumulate. The amount of fluid in the ventricles increases and the brain is then pushed outward.
Usually, the main symptom of normal-pressure hydrocephalus is an abnormally slow, unsteady, wide-legged walk. The feet may seem to stick to the floor (called a magnetic gait). People also have urinary incontinence and a tendency to fall.
Dementia may not develop until late in the disorder. Often, the first signs of dementia are difficulty planning, organizing, putting ideas or doing actions for a task in the right order (sequencing), thinking abstractly, and paying attention. Memory tends to be lost later.
Doctors may suspect normal-pressure hydrocephalus when people have the three typical symptoms:
However,the diagnosis of normal-pressure hydrocephalus cannot be based on symptoms alone, particularly in older people. Other dementias can cause similar symptoms, and in older people, many conditions can make walking difficult or cause urinary incontinence.
Doctors base a diagnosis of dementia on the following:
Symptoms, which are identified by asking the person and family members or other caregivers questions
Results of a physical examination, including a neurologic examination
Results of a mental status test
Results of additional tests, such as computed tomography (CT) or magnetic resonance imaging (MRI)
Mental status testing, consisting of simple questions and tasks, helps doctors determine whether people have dementia.
Sometimes more detailed testing (called neuropsychologic testing) is needed. This testing covers all the main areas of mental function, including mood, and usually takes 1 to 3 hours. This testing helps doctors distinguish dementia from other conditions that can cause similar symptoms, such as age-associated memory impairment, mild cognitive impairment, and depression.
Information from the above sources can usually help doctors rule out delirium as the cause of symptoms (see Table: Comparing Delirium and Dementia). Doing so is essential because delirium, unlike dementia, can often be reversed if promptly treated. Differences between the two include the following:
Brain imaging, usually magnetic resonance imaging (MRI) is done to check for excess cerebrospinal fluid. Finding excess fluid supports the diagnosis of normal-pressure hydrocephalus but does not confirm it.
To help with the diagnosis, doctors do a spinal tap (lumbar puncture) or place a temporary drain into the spinal cord to remove excess cerebrospinal fluid. If these procedures relieve symptoms, normal-pressure hydrocephalus is likely, and treatment is likely to be effective.
Treatment of normal-pressure hydrocephalus consists of placing a piece of plastic tubing (a shunt) in the ventricles of the brain and running it under the skin, usually to the abdomen (ventriculoperitoneal shunting). Cerebrospinal fluid is then drained away from the brain. The effects of this treatment may not be evident for several hours. This procedure may significantly improve the ability to walk and function and may lessen incontinence. However, mental function improves less and in fewer people. Thus, early diagnosis is important, so that people can be treated before dementia develops.
Other treatments are similar to treatments for other types of dementia.
Creating a safe and supportive environment can be very helpful (see Creating a Beneficial Environment for People With Dementia).
Generally, the environment should be bright, cheerful, safe, stable, and designed to help with orientation. Some stimulation, such as a radio or television, is helpful, but excessive stimulation should be avoided.
Structure and routine help people with dementia stay oriented and give them a sense of security and stability. Any change in surroundings, routines, or caregivers should be explained to people clearly and simply.
Following a daily routine for tasks such as bathing, eating, and sleeping helps people with dementia remember. Following a regular routine at bedtime may help them sleep better.
Activities scheduled on a regular basis can help people feel independent and needed by focusing their attention on pleasurable or useful tasks. Such activities should include physical and mental activities. Activities should be broken down in small parts or simplified as the dementia worsens.
Caring for people with dementia is stressful and demanding, and caregivers may become depressed and exhausted, often neglecting their own mental and physical health. The following measures can help caregivers (see Table: Caring for Caregivers):
Learning about how to effectively meet the needs of people with dementia and what to expect from them: Caregivers can get this information from nurses, social workers, organizations, and published and online materials.
Seeking help when it is needed:Caregivers can talk to social workers (including those in the local community hospital) about appropriate sources of help, such as day-care programs, visits by home nurses, part-time or full-time housekeeping assistance, and live-in assistance. Counseling and support groups can also help.
Caring for self: Caregivers need to remember to take care of themselves. They should not given up their friends, hobbies, and activities.
Before people with dementia become too incapacitated, decisions should be made about medical care, and financial and legal arrangements should be made. These arrangements are called advance directives. People should appoint a person who is legally authorized to make treatment decisions on their behalf (a health care proxy). They should discuss their health care wishes with this person and their doctor. Such issues are best discussed with all concerned long before decisions are necessary.
As dementia worsens, treatment tends to be directed at maintaining the person’s comfort rather than at attempting to prolong life.