Normal-pressure hydrocephalus is an abnormal increase of fluid in
the brain that puts pressure on the brain. It may be caused by a head injury,
an infection, a tumor, or by unknown causes.
Normal-pressure hydrocephalus is a rare, treatable cause of
dementia. It can occur at any age but is most common in older adults. Symptoms
include increased problems with mental abilities such as memory, trouble
walking, and problems with bladder control. Because the symptoms are similar to
those of other causes of dementia such as Alzheimer's or Parkinson's disease,
this condition is often not correctly diagnosed.
If the doctor suspects normal-pressure hydrocephalus, he or she
will evaluate how the person walks. Many people with this condition shuffle or
walk with their legs wide apart and feel that their feet are stuck to the
floor. Tests may include CT scan or MRI, lumbar puncture (spinal tap),
ultrasound, and other tests to help rule out other conditions that could be
causing the symptoms.
After the doctor has diagnosed normal-pressure hydrocephalus, often
a surgeon will place a tube called a shunt. The shunt runs under the skin from
the brain to the abdomen. The excess fluid drains through the shunt into the
abdomen, where it is reabsorbed by the body. This relieves the pressure in the
brain and usually corrects the symptoms.