Edward Ferguson, a civil engineer living in Vancouver, Wash., retired at age 65 from a job handling multimillion-dollar contracts. Five years later he could not balance a checkbook, walk without falling, drive a car, control his bladder or recognize his granddaughter.
Instead of the active retirement he had anticipated, Mr. Ferguson, now 74, thought he would spend the rest of his life in a wheelchair, incontinent and struggling with dementia. Ten doctors were unable to tell him what was wrong, but an Internet search by his daughter found a condition that seemed to match his symptoms: normal pressure hydrocephalus, or N.P.H.
The disorder involves a build-up of spinal fluid in the ventricles of the brain, causing pressure on nerves that control the legs, balance, bladder and cognitive function. “It’s as if the brain has reverted to babyhood,” Dr. Michael Kaplitt, a neurosurgeon at NewYork-Presbyterian Hospital/Weill Cornell Medical Center, said in an interview. “Like babies, people with N.P.H. walk slowly with feet wide apart, they are incontinent and have no memory.”
Dr. Kaplitt calls it “a classic triad of symptoms” that should alert doctors to the possibility of N.P.H.
Yet the condition is frequently misdiagnosed as dementia, Alzheimer’s disease, Parkinson’s disease or a spinal problem. Or it is attributed to age — nearly all who are affected are over 55.
Living With Uncertainty
“I was the most frustrated person in the world because at no time did a doctor give us a real diagnosis,” said Mr. Ferguson’s wife, Elva. The suspicions of Mr. Ferguson’s daughter eventually led to an accurate diagnosis through an M.R.I. and neurological tests. The Fergusons also found Dr. Jeffrey Chen, the director of neurotrauma for the Legacy Health System in Portland, Ore., who is skilled at treating this often-reversible condition.
Two days after surgery to install a programmable shunt that relieved the pressure on the frontal lobes of his brain, Mr. Ferguson walked across a room for the first time in a year. He was able to think and write clearly, and his incontinence improved.
The Fergusons are now looking forward to their 56th anniversary. Mr. Ferguson, who had contemplated suicide, considers himself to have a second chance at life. “At one point I saw no light at the end of the tunnel,” he said, “and now it is just so beautiful there.”
A Correctable Problem
No one knows how often N.P.H. occurs because it is so often missed or misdiagnosed. Estimates range from 50,000 to 375,000 people in the United States, with the higher figure more likely to be correct, said Dr. Mark Luciano, a neurosurgeon at the Cleveland Clinic.
“There are a lot of people out there with a correctable problem that is attributed to old age,” Dr. Luciano said. “When the problem is fixed, it’s like rescuing them from oblivion. A small percentage of people with dementia — maybe 10 or 15 percent — really have N.P.H.”
The disorder was recognized and named in 1965. But most doctors who treat older people are unaware of it or fail to think of it when treating patients with classic, albeit confusing, symptoms.
In most cases, the cause of N.P.H. is unknown. Some patients had suffered a severe head injury, stroke, meningitis or a brain tumor, perhaps decades earlier, which may have caused scarring or inflammation that gradually interfered with drainage of spinal fluid.
Dr. Kaplitt explained that each day the brain normally produces “about two soda cans’ worth of spinal fluid.” This fluid protects the brain’s soft tissue, which floats in the skull. Made deep in the brain, spinal fluid flows through a series of channels to the brain’s four ventricles and finally exits to outside the brain and spinal cord.
Each day the same amount of spinal fluid that is produced must be reabsorbed into the bloodstream. But if something slows or blocks its path, it builds up in the ventricles, which expand and press on nerves in the brain.
Diagnosis and Treatment
Normal pressure hydrocephalus is best diagnosed by a team that includes a radiologist, neuropsychologist and neurologist or neurosurgeon experienced in distinguishing this condition.
The best clue often comes from a careful medical history, since N.P.H. typically starts with gait problems, Dr. Luciano and his colleague, Dr. Ronan Factora, a geriatrician at the Cleveland Clinic, reported last year in the journal Geriatrics.
Cognitive impairment typically does not precede gait problems, they said, but when it does, or when dementia has become severe, the response to treatment is lessened. Incontinence, which starts out as urinary urgency, can occur at any point in the disease, and is often worsened by problems with walking or dementia.
Although there is no one route to diagnosis, if N.P.H. is suspected, a CT scan or M.R.I. of the brain can reveal one or more enlarged ventricles, an essential feature of the condition. On an M.R.I., Dr. Kaplitt said, the spinal fluid often is cloudy or turbulent.
Treating N.P.H. involves inserting a shunt into the brain to drain off accumulating spinal fluid and divert it to the abdomen, where it can be reabsorbed into the bloodstream. The ideal shunt has a valve and can be reprogrammed to regulate the drainage. Repeat surgery is a possibility if the shunt drains off too much or too little spinal fluid. While the shunt is not a cure for N.P.H., in the 70 to 80 percent of patients who benefit from it, it may give them a decade or more of near-normal life, the experts said.
The New York Times