What is Normal Pressure Hydrocephalus (NPH)?

What is Normal Pressure Hydrocephalus (NPH)?

Normal pressure hydrocephalus (NPH) is a brain condition that occurs when an unusual amount of cerebrospinal fluid (CSF) builds up in the brain’s ventricles or cavities. If the normal flow of CSF is blocked within the brain or the spinal cord, the ventricles will swell, causing pressure on the brain.

Normal pressure hydrocephalus is referred to as normal pressure as even with the additional brain fluid, CSF pressure often remains normal. The swelling of the brain ventricles due to the excess fluid can damage other brain tissue close by and cause difficulty walking, reasoning, thinking, and loss of bladder control.

Types of Hydrocephalus

Types

There are two different types of hydrocephalus: communicating and noncommunicating hydrocephalus.

Normal pressure hydrocephalus is considered communicating hydrocephalus.

  • Communicating hydrocephalus. This happens when the flow of CSF becomes blocked after it leaves the ventricles, which stay open. The term “communicating” means that CSF can continue to flow through the ventricles since the ventricles remain open.
  • Noncommunicating hydrocephalus is also referred to as obstructive hydrocephalus. This happens when the flow of CSF is blocked at one or more of the passages connecting the ventricles. Noncommunicating hydrocephalus is commonly caused by a condition called aqueductal stenosis, the narrowing of the small passage (aqueduct of Sylvius) in the ventricles in the center of the brain.

Signs & Symptoms of Normal Pressure Hydrocephalus

Symptoms

Normal pressure hydrocephalus symptoms include:

  • Difficulty walking. A distinctive walk is one of the first and most obvious symptoms of a patient with normal pressure hydrocephalus.
  • Mental impairment. Dementia includes losing interest in things once enjoyed, being forgetful, unable to carry out routine daily tasks, and losing short-term memory. However, not every person will develop mental impairment.
  • Loss of bladder control. Initially, these bladder issues may begin with urinary frequency and urgency.

Not all symptoms linked to hydrocephalus appear simultaneously; sometimes, only one or two symptoms may appear. In addition, these symptoms are related to aging; most people diagnosed with hydrocephalus are older than 60.

What Are the Causes and Risks for Normal Pressure Hydrocephalus?

Causes
  • Previous brain infection or injury
  • Preexisting brain tumor
  • History of brain surgery
  • Being over 60 years of age

However, many people develop NPH even when none of these factors are present. In these cases, the cause of the disorder is unknown.

Get Care

Trust NewYork-Presbyterian for Normal Pressure Hydrocephalus Care

NewYork-Presbyterian retains renowned neurosurgeons and neurologists recognized worldwide for their experience and expertise in handling and treating NPH and other neurological conditions and disorders involving the brain and spinal cord.

Our neurologists understand the symptoms and causes of NHP and work closely with leading neurosurgeons to care for your neurologic conditions.