The spaces in the center of the brain, called ventricles, are filled
with a clear colorless fluid called cerebrospinal fluid (CSF). CSF
also surrounds the brain and spinal cord. About one pint of CSF
is formed every day, and normally one pint is returned to the
blood every day (absorption). When the absorbing mechanism
breaks down, less CSF is absorbed and backs up, causing the CSF
pressure to increase and the ventricles to enlarge and produce
hydrocephalus. In time, the CSF finds other less adequate
absorptive pathways and the pressure returns to normal.
However, the ventricles remain dilated.

Symptoms
According to Dr. Portnoy, the disease usually occurs in people
about age 60, but can appear earlier. Symptoms include: mild to
profound dementia, difficulty walking (gait disturbance) and loss
of control of bladder and/or bowel. Individuals with NPH may
have had a head injury, tumor, meningitis, brain hemorrhage or
stroke. However, the majority do not appear to have a specific
cause, Dr. Portnoy says.

It is estimated that between 5 and 10 percent of patients with
dementia or Alzheimer’s disease actually have NPH. Some NPH
patients with difficulty walking have been misdiagnosed as having
Parkinson’s disease. Unlike Alzheimer’s or Parkinson’s, NPH is
curable.

"The most important factor in diagnosing NPH is suspecting
that a patient has NPH," Dr. Portnoy explains. "In that case, a
physician will order a CT scan or MRI. NPH is indicated if the
ventricles are enlarged and there is not a significant amount of
brain atrophy."

Treatment
The treatment for NPH is the insertion of a shunt. This is a
mechanical device composed of a catheter placed either in
the ventricle of the brain or in the lumbar spine; a valve that
regulates the amount of CSF that passes through the shunt and
a distal catheter that empties the CSF -- most commonly, into
the peritoneal cavity. The shunt lies under the skin.

In most cases, the patient can be discharged on the same day
or following day.

Referral
For information or an appointment, call the SJMO
hydrocephalus clinic, 248-858-2606.