Normal Pressure Hydrocephalus

About Normal Pressure Hydrocephalus

General Information

• Normal pressure hydrocephalus (NPH) involves enlargement of the ventricles, which are cerebro spinal fluid (CSF)-filled spaces within the brain. The enlargement stretches nerve pathways in the brain, creating a trio of symptoms: difficulty walking, urinary incontinence and dementia.
• Enlargement of the brain ventricles can occur for a variety of reasons, including brain loss. Distinguishing between the “ballooning” ventricles of hydrocephalus and enlargement of the ventricles due to loss of brain tissue, or atrophy, can be difficult.
• The disorder usually occurs in adults over age 60. Note that the symptoms, diagnosis and treatment for NPH are different than those for children with hydrocephalus.  Please use caution when reading about general hydrocephalus since it usually refers to children.

Symptoms

• Gait problems range from mild imbalance with a wide-based, short, slow and shuffling walk to the complete inability to walk.
• Bladder control difficulties begin as a need to rush to the bathroom but later may manifest as incontinence.
• Mild dementia is usually the last symptom to present and typically is recognized by family members as forgetfulness and short-term memory loss.

Diagnosis

• An NPH diagnosis is difficult to make based solely on the clinical examination and magnetic resonance imaging (MRI) findings. In order to be more confident of the diagnosis, additional tests are often needed.
• At UCLA, we perform several tests in order to identify patients with the highest likelihood of improving with a shunt procedure and, conversely, those who should not receive a surgical shunt procedure.
• The typical evaluation involves a four-day hospital stay and consists of three steps:
  • 1) Continuous measurement of intracranial pressure.
  • 2) Measurement of the CSF outflow resistance.
  • 3) Assessing the clinical response to temporary CSF drainage.

Treatment

• Traditional treatment of NPH involves surgical placement of a shunt that diverts CSF from the brain to another part of the body.
  • There are different types of shunt configurations, but the most commonly used at UCLA are the ventriculoatrial (VA) and ventriculoperitoneal (VP) shunt. Both involve placing a catheter into the brain ventricle to access the CSF.
    • The VA shunt diverts the CSF to the vein just above the atrium of the heart. (The catheter is inserted into the jugular vein.)
    • The VP shunt diverts CSF to the abdominal cavity.
  • The shunt system involves placement of a programmable valve that controls the CSF drainage rate.
    • Because it is at the lowest drainage setting, the patient might not see an improvement immediately after surgery.
    • The valve will likely have to be reprogrammed in clinic a couple of times until the correct setting is achieved.
    • Valve adjustment is easy, quick and painless.
      
• Endoscopic treatment of hydrocephalus (third ventriculostomy) is an option for some patients with normal pressure hydrocephalus.
  • Endoscopic treatment of hydrocephalus (third ventriculostomy) simply forms a detour at the base of the brain to bypass the obstruction.
  • This procedure is completed through a single dime-sized hole in the skull and can take as little as 15 minutes to perform. A neck and abdominal incision are not required as with a shunting system.
  • The procedure can be effective in both obstructive and communicating hydrocephalus and applied to both children and adults.
  • Because no foreign device (shunt system) is needed, the risks of infection are reduced.
  • Recovery and return to work are rapid.

Outcome

• In the best of circumstances, chances of improvement are 90 percent. In some cases, the probability of improving may be only 50 percent.
• Although the degree of improvement can be amazing, some patients improve very little. In general, patients likely will improve at least as much was seen during the lumbar drainage procedure.

The Neuro-ICU cares for patients with all types of neurosurgical and neurological injuries, including stroke, brain hemorrhage, trauma and tumors. We work in close cooperation with your surgeon or medical doctor with whom you have had initial contact. Together with the surgeon or medical doctor, the Neuro-ICU attending physician and team members direct your family member's care while in the ICU. The Neuro-ICU team consists of the bedside nurses, nurse practitioners, physicians in specialty training (Fellows) and attending physicians. UCLA Neuro ICU Family Guide