Learn about the symptoms, diagnosis, and treatment options for normal pressure hydrocephalus (NPH) at Meri Sehat. Stay informed and seek proper care.

Normal Pressure Hydrocephalus

Overview

Normal pressure hydrocephalus (NPH) is defined as an accumulation of excessive cerebrospinal fluid (CSF) in the brain with normal CSF pressure. 
Hydrocephalus occurs when the body&#39;s natural system for draining and absorbing excess cerebrospinal fluid fails. It results in an accumulation of fluid within the ventricles. 
&nbsp;

The ventricles within the brain contain a clear liquid, called cerebrospinal fluid (CSF), that cushions the brain and spinal cord. This fluid circulates around the brain, supplying it with nutrients and removing any waste products.

The ventricles expand to take in the extra fluid and then press on various brain parts, resulting in gait disturbances, dementia, and urinary continence. However, the fluid pressure within the brain is not raised. Thus, the name &lsquo;normal pressure hydrocephalus&rsquo;.&nbsp;Infection, tumor, injury, and bleeding can all contribute to hydrocephalus.

Although normal pressure hydrocephalus can affect all age groups, it is most common among the elderly, especially people in their 60s and 70s. According to The Hydrocephalus Association, an estimated 700,000 adults experience NPH6. However, it is often confused with Alzheimer&rsquo;s or Parkinson&rsquo;s disease.

It is necessary to seek treatment as soon as possible to avoid serious, life-threatening complications. 
&nbsp;

There are two types of normal pressure hydrocephalus - primary and secondary<a href="#accordion">[7]</a>. While both are communicating types of hydrocephalus, they have some distinctive features. 
&nbsp;

<h5>Primary (Idiopathic) NPH</h5>

Primary NPH has no detectable cause. According to experts, it may be caused by one or more age-related problems with how the body produces, circulates, and reabsorbs cerebrospinal fluid. It accounts for roughly half of all cases. 

Idiopathic NPH (iNPH) primarily affects the elderly. Most patients with iNPH are over 80, and the mean age of onset is around 70 years old. Males and females are equally affected. It is estimated that iNPH accounts for approximately 6% of all dementia cases<a href="#accordion">[7]</a>. 
&nbsp;

<h5>Secondary (Symptomatic) NPH</h5>

Secondary NPH occurs when another medical condition interferes with the body&#39;s ability to produce, circulate, or reabsorb CSF. Traumatic brain injury, earlier brain infection, bleeding, or radiation can lead to secondary NPH. Unlike primary NPH which mainly affects the elderly, secondary can affect people of all ages.&nbsp; 
&nbsp;

Signs and Symptoms

NPH signs and symptoms typically occur and aggravate over three to six months. Although they are subtle at first, they worsen slowly with time. 

According to a recent study of potential NPH signs, 21.2% of nursing home patients have gait abnormalities, 9.4% have dementia, and 14.7% have incontinence<a href="#accordion">[4]</a>.

NPH manifests itself in three distinct groups of signs and symptoms. Hakim&#39;s triad refers to the three major signs of NPH that are given below<a href="#accordion">[4]</a>:

<ol>
	<li>Gait disturbances</li>
	<li>Urinary incontinence</li>
	<li><a href="https://merisehat.pk/disease/dementia">Dementia</a> 
	&nbsp;</li>
</ol>

Approximately 50% to 75% of people with NHS present with the complete Hakim triad<a href="#accordion">[7]</a>. While gait and cognitive issues occur in 80% to 95%, and urinary incontinence takes place in 50% to 75% of individuals<a href="#accordion">[7]</a>. 
&nbsp;

<h5>Gait Issues</h5>

This is often the first and most common symptom of NPH. It also resolves most rapidly postoperatively.

The terms &lsquo;shuffling&rsquo;, &lsquo;wide-based&rsquo;, and &lsquo;magnetic&rsquo; are often used to describe the gait in idiopathic normal pressure hydrocephalus. As the disease progresses and worsens, the patient&rsquo;s gait may become slow, short-stepped, and glue-footed.

People with NPH may experience the following symptoms: 
&nbsp;

<ul>
	<li>Difficulties Lifting The Feet</li>
</ul>

The individual&rsquo;s feet may appear stuck to the ground as they walk. One common explanation compares the struggle of lifting the feet to how magnet resist being pulled away from a magnetic surface. 
&nbsp;

<ul>
	<li>Shorter And Less Stable Steps</li>
</ul>

The individual may appear to be shuffling their feet. It also increases the chances of stumbling, collapsing, and falling.

<ul>
	<li>Freezing Of Gait Or Walk Erratically</li>
</ul>

The individual cannot take a step or continue walking once they have begun. They may also pause or struggle with broad turns while walking.

<ul>
	<li>Toes Turn In An Outward Direction While Walking</li>
</ul>

NHS can also trigger the person to walk with their toes wider apart, resulting in a stepping pattern similar to that of a penguin. 
&nbsp;

<h5>Urinary Incontinence</h5>

The gait disturbances are frequently followed by episodes of urinary incontinence, which may include the following signs and symptoms:

<ul>
	<li>A recurrent need to urinate (Urinary frequency)</li>
	<li>An urge to urinate (Urinary urgency)</li>
	<li>Loss of bladder control (Incontinence) 
	&nbsp;</li>
</ul>

If a person with this symptom loses bladder control, they may feel awkward and uncomfortable. However, a few individuals don&#39;t seem to observe or feel uneasy about this. Not feeling awkward or distressed may result from the third major symptom in Hakim&#39;s triad, cognitive difficulties.

Occasionally, people may also lose control of their bowels. 

<h5> 
Cognitive Difficulties</h5>

Cognitive difficulties are the third major NPH sign. The normal thought process begins to slow down as well. It is a sign that can manifest as or be the cause of any of the following:

&nbsp;

<ul>
	<li>Physical and Mental Slowness</li>
</ul>

It occurs when an individual appears to be thinking or moving more gradually than routine.

<ul>
	<li>Memory Issues</li>
</ul>

People with this disorder frequently seem to be forgetful or absent-minded.

<ul>
	<li>Executive Dysfunction</li>
</ul>

Due to this, individuals struggle to control their emotions, thoughts, and actions. It can also manifest as difficulties with focus and concentration and slow and confused decision-making.

<ul>
	<li>Emotional Alterations</li>
</ul>

Individuals with NPH may seem unconcerned or uninterested in activities they once enjoyed. These signs and symptoms could be indicative of moderate dementia. They should begin to get better once NPH is treated.

The following symptoms can be associated with increased brain pressure:

<ul>
	<li>Headache</li>
	<li>Nausea</li>
	<li>Difficulty in focusing the eyes 
	&nbsp;</li>
</ul>

Note: Any of these issues and changes in mood or behavior necessitate a visit to your doctor. 
&nbsp;

Causes

The causes of normal pressure hydrocephalus are divided based on the type. They are given below: 
&nbsp;

<ol>
	<li>&nbsp;Idiopathic (Primary) NPH</li>
</ol>

There is no detectable cause of idiopathic normal-pressure hydrocephalus. 
&nbsp;

<ol start="2">
	<li>&nbsp;Symptomatic (Secondary) NPH</li>
</ol>

The following are some conditions that can trigger secondary NPH:

<ul>
	<li>Brain aneurysm - A swollen blood vessel that compresses the nearby brain tissue, which can bleed if it tears or ruptures.</li>
	<li>Bleeding in or in the vicinity of your brain (intracranial hemorrhage).</li>
	<li>Brain tumors (also includes cancer).</li>
	<li>Infections of the brain or other associated regions of the nervous system (for example, encephalitis or meningitis).</li>
	<li><a href="https://merisehat.pk/disease/stroke">Stroke</a>. </li>
	<li>Traumatic brain injuries - These can also include injuries in or in the vicinity of the brain resulting from medical procedures.</li>
</ul>

&nbsp;

The above causes block the drainage of CSF. Thus, as the fluid accumulates, the ventricles enlarge and pressure builds up within the brain. However, the pressure is not as high as in other types of hydrocephalus. The enlarged ventricles press on the brain regions responsible for controlling leg movements, the bladder, and cognitive and mental processes. 
&nbsp;

There are currently no specific screening tests for normal pressure hydrocephalus. However, a recent study evaluated using CT scans to screen for NPH in the elderly after falls<a href="#accordion">[8]</a>. As per the results, screening the elderly for NPH after a fall can help identify patients at an earlier stage, improving prognosis. 
&nbsp;

Diagnosis

NPH is frequently difficult to detect and evaluate because it shares some signs and symptoms of dementia and other age-related ailments. However, the sequence of dementia, walking difficulties, and urinary issues should alert the doctor to the likelihood of NPH.

It is also regular for NPH to occur concurrently with age-related conditions. The doctor may refer patients to a neurologist or neurosurgeon at any time during this process to complete the diagnosis and start treatment.

After taking a detailed history and conducting a physical examination, doctors typically perform imaging tests to establish a diagnosis. 
&nbsp;

<h5>History</h5>

The diagnosis starts with a medical interview, during which the neurologist will inquire about the following: 
&nbsp;

<ul>
	<li>The symptoms and when they first appeared.</li>
	<li>Current and previous medical and mental issues.</li>
	<li>Family history of dementia or other medical disorders</li>
	<li>Current and previous medications</li>
	<li>Professional and travel experiences.</li>
	<li>Habits and way of life. 
	&nbsp;</li>
</ul>

<h5>Physical And Neurological Exam</h5>

These are examinations in which a medical professional looks for observable signs or symptoms of a condition. They also assess the individual&#39;s senses (eyesight, hearing, touch, and so on), reflexes, mental status, gait, and arm and leg muscle power. 
&nbsp;

<h5>&nbsp;CT (Computed Tomogram)</h5>

Although CT can aid in visualizing a few anatomical alterations in the brain, doctors cannot use it alone to evaluate normal pressure hydrocephalus. However, it can help detect ventricular enlargement and measure the flow of CSF in the brain. 

<ol>
	<li>&nbsp;MRI (Magnetic Resonance Imaging)</li>
</ol>

MRI is the preferred investigational imaging technique for normal pressure hydrocephalus to image structural alterations. MRI imaging tests allow a neurologist to look inside the head to evaluate the brain and regions of fluid accumulation. Alzheimer&rsquo;s disease and other brain disorders can result in the atrophy of brain tissue that causes the ventricles to appear larger than normal. However, in NPH, the ventricles are enlarged but the brain tissue may not appear shrunken. 

CSF flow studies and magnetic resonance spectroscopy (MRS) can help to confirm an iNPH evaluation. Evan&rsquo;s index of at least 0.3 is required to establish a diagnosis of NPH on MRI or CT. 
&nbsp;

<ol start="2">
	<li>&nbsp;Cisternography</li>
</ol>

Cisternography is not extensively used for diagnosing NPH. It helps evaluate CSF absorption. 
&nbsp;

<ol start="3">
	<li>&nbsp;Lumbar Puncture (Spinal Tap) </li>
</ol>

This technique entails measuring CSF pressure and withdrawing a small amount of CSF from the region surrounding the spinal cord in the lower back. CSF is analyzed for abnormalities that may indicate a problem.

A spinal tap may also enable doctors to remove extra CSF, which may alleviate the signs and symptoms. However, this is generally short-term, and symptoms will appear as CSF accumulates again.

The medical professional may suggest other tests based on the individual&rsquo;s signs and symptoms. It is generally done to rule out other ailments comparable to NPH. 
&nbsp;

Treatment

NPH is typically a condition that doctors can treat. The treatment strategy differs depending on whether the NPH is primary/idiopathic or secondary/symptomatic. Unlike other brain-associated conditions, NPH is hardly ever treated with medicine. It is because NPH does not respond to medicine, though medications may alleviate some symptoms associated with NPH.

Doctors may conduct a levodopa challenge to rule out Parkinson&rsquo;s disease. In NPH, levodopa or dopamine agonists do not cause any response. 

Normal pressure hydrocephalus can occasionally be controlled or even reversed surgically. Treatment for non-surgical candidates includes measures to alleviate mood and behavioral issues, cope with physical issues, for example, incontinence and walking problems, and maximize physical, mental, and social working. 
&nbsp;

<ol>
	<li>
	<h5>&nbsp;&nbsp;Primary/ Idiopathic NPH Treatment</h5>
	</li>
</ol>

The majority of cases of primary/idiopathic NPH are treatable. Surgery is the most common and efficacious treatment for idiopathic NPH. 
&nbsp;

<ul>
	<li>&nbsp;Shunt Placement</li>
</ul>

This involves the insertion of a shunt. A shunt consists of two tubes (known as catheters), one for fluid to enter and one for fluid to exit, connected by a valve. The tube is passed through the skin from the head to another body part, typically the peritoneum (the lower belly). If the ventricle becomes too full, the elevated pressure forces fluid into the inflow catheter, opens the valve, and permits extra fluid to depart through the outflow catheter. The fluid drains safely and is absorbed by the bloodstream later on.

A few present-day shunt valves are programmable, allowing the provider to change the settings without surgery. They also appear on X-rays, allowing the provider to inspect the valve and ensure the correct settings. Some present-time shunts are even MRI-safe, which means people can have an MRI even if they have one of these valves.

Shunt surgery is not a cure. It does not address the main cause of NPH. However, it can help to alleviate the symptoms. The shunt will stay in place indefinitely. When properly implanted, the shunt is often undetectable to others.

Shunt operations are not appropriate for every individual with NPH. Many individuals who have a shunt operation experience significant symptom relief. Some people&#39;s symptoms improve only to aggravate again. Others gain little or no benefit. Even experts cannot foresee who will benefit from this and who will not. 

The earlier the NPH is detected, the better the likelihood that the surgery will be effective. Individuals with moderate symptoms, on average, fare better with this surgery. The shunt operation, like any other surgery, can result in complications. Complications include shunt infection and the development of blood clots all over the brain. 
&nbsp;

<ul>
	<li>&nbsp;Endoscopic Third Ventriculostomy</li>
</ul>

Another procedure, an endoscopic third ventriculostomy, sometimes replaces shunt placement. An endoscope (a narrow tube with a lighted camera at the end) makes a tiny hole in the ventricle floor during the endoscopic third ventriculostomy. The hole allows CSF to exit the brain. 
&nbsp;

<ol start="2">
	<li>
	<h5>&nbsp;Symptomatic/Secondary NPH Treatment</h5>
	</li>
</ol>

Secondary NPH is treatable, but only if caused by a curable condition. Secondary NPH treatment varies greatly depending on the underlying cause. 
&nbsp;

Normal pressure hydrocephalus can lead to the following complications: 
&nbsp;

<ul>
	<li>Progressive dementia causing problems with thinking and reasoning</li>
	<li>Difficulty walking</li>
	<li>Loss of blood control 
	&nbsp;</li>
</ul>

&nbsp;Early diagnosis and treatment of this ailment can have a big impact on the intensity of the symptoms, improving performance and survival. Even those who have experienced symptoms for a long time without receiving therapy can benefit from better cognitive performance and a longer lifespan. 
&nbsp;

The following factors increase the risk of normal pressure hydrocephalus: 
&nbsp;

<ul>
	<li>Age of 60 or more</li>
	<li>Cerebrovascular disease</li>
	<li><a href="https://merisehat.pk/disease/hypertension-57">Hypertension</a></li>
	<li>Vascular disorders</li>
	<li>Brain infection</li>
	<li>Brain tumor</li>
	<li>History of brain surgery</li>
	<li>Brain injury</li>
	<li><a href="https://merisehat.pk/disease/alzheimers-disease">Alzheimer&rsquo;s disease</a> 
	&nbsp;</li>
</ul>

The following factors can help reduce the risk of normal pressure hydrocephalus: 
&nbsp;

<ul>
	<li>
	&nbsp;Don&rsquo;t Ignore Infections
	</li>
</ul>

As eye and ear infections are particularly likely to move to the brain and result in encephalitis or <a href="https://merisehat.pk/disease/bacterial-meningitis">meningitis</a>, they should be treated with extreme care.

<ul>
	<li>&nbsp;Wear Safety Equipment</li>
</ul>

Secondary NPH may be brought on by traumatic brain injury. People can decrease their risk of suffering a head injury by using a helmet as well as other safety precautions.

<ul>
	<li>&nbsp;Manage Health Conditions</li>
</ul>

High blood pressure and other conditions can cause aneurysms and brain bleeding, both of which can result in NPH. People can lower their risk of developing these issues by controlling associated illnesses like Type 2 diabetes or excessive cholesterol as well as blood pressure. 
&nbsp;

Key Points

<ul>
	<li>Hydrocephalus occurs when the body&#39;s natural system for draining and absorbing excess CSF fails. Thus, resulting in an accumulation of fluid within the ventricles.</li>
	<li>Normal pressure hydrocephalus (NPH) is defined as an accumulation of excessive cerebrospinal fluid (CSF) in the brain with normal CSF pressure.</li>
	<li>There are two types of normal pressure hydrocephalus - primary and secondary. While both are communicating types of hydrocephalus, they have some distinctive features. </li>
	<li>NPH manifests itself in three distinct groups of signs and symptoms. Hakim&#39;s triad refers to the three major signs of NPH which includes gait disturbances, urinary incontinence, and dementia. </li>
	<li>Although normal pressure hydrocephalus can affect all age groups, it is most common among the elderly, especially people in their 60s and 70s. 
	&nbsp;</li>
</ul>

[1] Yatsu FM. Normal pressure hydrocephalus. Calif Med. 1971;115(3):49.

[2] Gallia GL, Rigamonti D, Williams MA. The diagnosis and treatment of idiopathic normal pressure hydrocephalus. Nat Clin Pract Neurol. 2006;2(7):375–81.

[3] Daou B, Klinge P, Tjoumakaris S, Rosenwasser RH, Jabbour P. Revisiting secondary normal pressure hydrocephalus: does it exist? A review. Neurosurg Focus. 2016;41(3):E6.

[4] Shprecher D, Schwalb J, Kurlan R. Normal pressure hydrocephalus: diagnosis and treatment. Curr Neurol Neurosci Rep. 2008;8(5):371–6.

[5] Afrashteh F, Ghafoury R, Almasi-Doghaee M. Cerebrospinal fluid biomarkers and genetic factors associated with normal pressure hydrocephalus and Alzheimer’s disease: a narrative review. Egypt J Med Hum Genet. 2022;23(1):1–8.

[6] Normal pressure hydrocephalus. Alzheimer's Disease and Dementia.

[7] M Das J, Biagioni MC. Normal Pressure Hydrocephalus. [Updated 2022 Jun 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.

[8] Oike R, Inoue Y, Matsuzawa K, Sorimachi T. Screening for idiopathic normal pressure hydrocephalus in the elderly after falls. Clinical Neurology and Neurosurgery. 2021;205:106635. doi:10.1016/j.clineuro.2021.106635.