Normal Pressure Hydrocephalus Symptoms & Causes

Hydrocephalus is characterized by an increase of cerebrospinal fluid in the brain’s ventricles or cavities. In “obstructive hydrocephalus” the normal flow of cerebrospinal fluid throughout the brain and spinal cord is blocked in some way and backs up behind the obstruction leading to increased pressure. In “communicating hydrocephalus” there is no obvious obstruction to the flow of CSF, but the re-absorption of CSF back into the blood stream is impaired. NPH is a form of communicating hydrocephalus and is the most common form of hydrocephalus that is seen in the elderly. 
Types of Hydrocephalus
  • Secondary hydrocephalus – Common causes of secondary hydrocephalus are a brain tumor, hemorrhage, infection or a trauma, such as falling down and hitting your head.          
  •  Idiopathic hydrocephalus – Some people in their 60s, 70s and 80s develop hydrocephalus without any known cause, or idiopathic. In such patients, the pressure increase may be very mild and not always detectable, a condition known as normal pressure hydrocephalus (NPH).
Normal Pressure Hydrocephalus symptoms and causes are evaluated and treated by neurological and neurosurgical specialists at the Normal Pressure Hydrocephalus Center at North Shore-LIJ's renowned Cushing Neuroscience Institute. Normal pressure hydrocephalus (NPH) is a mild form of hydrocephalus ("water on the brain") that is harder to detect, diagnose and treat than other types of hydrocephalus.

Normal Pressure Hydrocephalus Causes
 

Normal pressure hydrocephalus can occur in people of any age, but it is most common in the elderly population. Several factors that contribute to development of NPH are subarachnoid hemorrhage, head trauma, infection, tumor or previous brain surgery. However, many people develop normal pressure hydrocephalus even when none of these factors are present. In these cases, although the cause of the disorder is unknown, it is believed that the re-absorption of cerebrospinal fluid into the blood stream is reduced in many of these cases.
Normal Pressure Hydrocephalus Symptoms
 
People with normal pressure hydrocephalus often have a combination of three symptoms that often help establish the diagnosis:
  • Mental confusion – Mild forgetfulness, short-term memory loss, loss of interest in normal activities are often seen in people with NPH.
  • Gait disturbance  Difficulty in walking can take many forms, such as taking small shuffling steps, a tendency to fall, a feeling that your feet are too heavy or difficulty climbing stairs.
  •  Urinary incontinence – Impaired bladder control consists of difficulty in holding back urine.
Because NPH symptoms are similar to those of Alzheimer's, Parkinson's and other movement disorders, NPH is often misdiagnosed or unrecognized which results in patients not receiving the appropriate treatment.
Diagnostic Workup for Normal Pressure Hydrocephalus

Normal pressure hydrocephalus may be difficult to diagnose, since not all of the symptoms may appear at the same time. Sometimes these same symptoms of normal pressure hydrocephalus are found in other disorders of the elderly, such as Alzheimer’s disease, Parkinson’s disease and osteoarthritis. There is no single test that establishes the diagnosis of NPH. The usual series of tests that are commonly used for this purpose include the following:

  • Patient history and examination – is the basis of establishing the clinical diagnosis.
  • CT scan (Computerized Tomography) of the head – A CT scan is often done as the first test, but may not be needed if an MRI has been obtained. The scan shows enlargement of the ventricles, or cavities, and is helpful in ruling out other specific causes for the hydrocephalus.
  • MRI (Magnetic Resonance Imaging) – An MRI is more sensitive to abnormalities of the brain tissue and is a key component of the diagnostic work-up.
  • Neuropsychological testing – A thorough neurological evaluation will be done by a trained neuropsychologist and can be helpful in getting a clearer picture of the type and severity of mental impairment. It can also help in following the course of a patient’s disease.
  • Gait testing – This computerized measure helps in quantifying a patient’s gait (walking) impairment and is also helpful in documenting improvement with treatment.
  • Spinal tap or lumbar puncture (LP) – A very fine-gauge needle is placed into the spinal canal, and the pressure of the cerebrospinal fluid is measured. At this time, the CSF is also examined for any other abnormal findings.
  •  Lumbar CSF drainage – A catheter is often inserted into the spine in the lower back for continuous drainage of cerebrospinal fluid over a three-day period. This procedure is more sensitive to improvement than a lumbar puncture alone.
  •  Intracranial pressure monitoring – This is sometimes used in cases where the diagnosis is unclear and actual monitoring of the pressure inside the head is thought to be necessary.

Make an appointment at our Normal Pressure Hydrocephalus Center
Cushing Neuroscience Institute’s Normal Pressure Hydrocephalus Center makes it easy for you to take the first steps in ensuring the best neurological care for yourself and your family. Simply click on Request an Appointment, email us at neuro@nshs.edu or call us at (516) 773-7737 or (516) 562-3816.