Normal pressure hydrocephalus (NPH)

What is NPH?

Normal pressure hydrocephalus (NPH) is a brain disorder whereby cerebrospinal fluid (CSF) – a clear, colorless body fluid surrounding your brain and spinal cord, accumulates in your brain’s ventricles, causing them to become enlarged. The brain’s ventricles are cavities in your brain filled with CSF. As these ventricles enlarge, they press and thus damage nearby brain tissue, resulting in problems with thinking, reasoning, memory and control over certain parts of your body. 

NPH is unlike other types of hydrocephalus as it develops slowly over time. The natural drainage of CSF from the ventricles is blocked gradually, causing the ventricles to enlarge little by little. 

NPH is known as ‘normal pressure’ as it often has little to no effect on the pressure within one’s skull, also known as the intracranial pressure (ICP). It is a treatable disorder that is most common among the elderly, yet is frequently misdiagnosed as Alzheimer’s disease or Parkinson’s disease. According to the Hydrocephalus Association, it is estimated that more than 700,000 Americans have NPH, but less than 20% are accurately diagnosed with it [1].

Normal pressure hydrocephalus

How will having NPH affect me?

Restricted mobility. Firstly, you will most likely have trouble standing up or moving around on your feet. This may make climbing stairs, walking up slopes and even turning around extremely tiring and difficult. As a result, you may also notice yourself tripping or falling down more often than usual. 

Mild dementia. With NPH, you may also experience mild dementia – increased forgetfulness, a loss of interest in daily activities and a decreased control over your own emotions. You may find yourself being unable to remember what you had for breakfast, or often overreacting to things that did not use to irritate you. 

Loss of bladder control. Lastly, having NPH may entail a loss of bladder control. Initially, you may find yourself needing to urinate more frequently than usual. However, patients with severe cases of NPH often begin to lose complete control over their bladders. 

What does having NPH feel like?

Symptoms of NPH are often mistaken for other disorders and diseases,  or simply disregarded as signs of old age. However, there are a few distinctive characteristics of NPH which you can look out for. 

Difficulty standing and moving around on your feet is the main tell-tale sign of NPH. Patients with NPH often parallel the sensation of walking with that of walking on a rocking boat. Furthermore, a decline in memory and thinking skills, accompanied by rapid mood changes may be an indication of NPH. Lastly, the inability to control one’s bladder is a symptom of NPH, often in its later stages of development.

What are the causes and risk factors of NPH?

The reason for CSF buildup resulting in NPH is largely unknown. However, in certain cases, you may develop NPH due to the presence of a brain tumor, bleeding (also known as hemorrhage) resulting from a brain injury or stroke, or a neuroinfection such as meningitis. 

The risk of NPH also comes with age. Research has shown how NPH is most prevalent among the elderly, especially those over the age of 80 [2].

How is NPH diagnosed?

When visiting a doctor, your doctor will most likely conduct a thorough medical examination before definitively diagnosing you with NPH. Your doctor may ask you about your medical and family history. 

In addition, your doctor will make use of neuroimaging, such as CT and MRI scans to detect abnormal enlargement of the brain’s ventricles. This will also aid in differentiating NPH from other diseases which may have similar symptoms as NPH, such as Alzheimer’s. 

Lastly, your doctor may perform a lumbar puncture (LP), whereby a thin needle is inserted between two lumbar bones in your lower back to remove a sample of CSF, in order to diagnose your NPH. This procedure is relatively painless, though you may experience some headaches and back pain in the next few days.

How do I prevent myself from getting NPH?

Unfortunately, there are currently no known ways of preventing NPH.

How is NPH treated?

One of the most common treatments for NPH is surgery, whereby your surgeon will place a tube, also known as a shunt, into your brain’s ventricles to drain the excess CSF. The shunt will then be passed beneath the skin into your abdomen, where excess CSF will flow to and be absorbed by your body. 

Not everyone will be able to benefit from this treatment. However, early diagnosis and treatment of NPH will significantly increase the chances of full or partial recovery. 

If you are currently experiencing symptoms of NPH, visit a doctor and seek medical attention immediately.

  1. Normal Pressure Hydrocephalus | Hydrocephalus Association. (2014, June 18).
  2. Jaraj, D., Rabiei, K., Marlow, T., Jensen, C., Skoog, I., & Wikkelso, C. (2014). Prevalence of idiopathic normal-pressure hydrocephalus. Neurology, 82(16), 1449–1454. 
  3. Normal Pressure Hydrocephalus. (2015). Alzheimer’s Disease and Dementia.