What is normal pressure hydrocephalus? 

Normal pressure hydrocephalus (NPH) is an abnormal buildup of cerebrospinal fluid (CSF) in the brain’s ventricles, or cavities.

Also called Hakim's syndrome and symptomatic hydrocephalus, it occurs when the normal flow of CSF is blocked. This blockage enlarges the ventricles, putting pressure on the brain.


NPH is most common in the elderly, though it can occur in people of any age.

Common causes of NPH include:

  • Subarachnoid hemorrhage
  • Head trauma
  • Infection
  • Tumor
  • Surgical complications

It's possible to develop NPH without these causes being present. In many cases, the cause of NPH is unknown. 


Symptoms of NPH include:

  • Mental impairment and dementia
  • Gait problems
  • Incontinence problems
  • Trouble moving, complaining of feeling "stuck"

NPH is often misdiagnosed because these symptoms are similar to other disorders, such as Alzheimer's disease, Parkinson's disease and Creutzfeldt-Jakob disease.

As a result, many cases go unrecognized and untreated.

Diagnosis and treatment

To diagnose NPH, a variety of tests are performed to rule out other conditions.

Tests may include:

  • Brain scans (CT or MRI)
  • Intracranial pressure monitoring  
  • Spinal tap or lumbar catheter

Treatment usually involves surgery to insert a shunt to carry CSF to another area of the body and relieve pressure in the brain.


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