Key features

NPD is a rare disorder that involves the build-up of fluid in the brain. It typically has three symptoms: (1) difficulty walking, (2) loss of bladder control and (3) mental decline. A person’s cognitive responses become delayed, but they tend to be accurate and appropriate to the situation when they finally come. Gait problems and incontinence are common in the late stages of all dementias, but they are rarely prominent early features except in NPH.

Treatment

• NPH can occasionally be treated by surgically inserting a long, thin tube called a shunt to drain fluid from the brain to the abdomen. This treatment tends to help more with walking and bladder control than with mental decline.
  
  
• Certain television broadcasts and commercials have portrayed NPH as a highly treatable condition that is often misdiagnosed as Alzheimer’s, another dementia or Parkinson’s disease. However, most experts believe it is unlikely that significant numbers of people diagnosed with Alzheimer’s or Parkinson’s actually have NPH that could be treated with surgery.

Pathological substrate

NPH occurs when fluid surrounding the brain and spinal cord is unable to drain normally. The fluid builds up, enlarging spaces in the brain called ventricles. As the ventricles expand, they can compress and damage nearby tissue.