Alzheimer’s disease or NPH?

By DEE ANN DUREN

VIEW ON HEALTH

Wet, wobbly and wacky.

That's the phrase used to teach medical students how to recognize the symptoms of normal pressure hydrocephalus (NPH). Unfortunately, as the condition affects a relatively small percentage of people, it may be a long time before the practicing physician needs to put the lesson to use.For that and other reasons, if you are elderly or have a loved one who is, knowing the symptoms of NPH may help save a life.

ABOUT HYDROCEPHALUS

Hydrocephalus, also known as water on the brain, occurs when there is a buildup of cerebrospinal fluid (CSF), the watery liquid that cushions the brain and spinal tissue from injury and provides nutrients to the central nervous system. In a healthy system, the CSF produced daily in the cavities of the brain called ventricles does its job and then is absorbed by other tissues.

With hydrocephalus, the amount of CSF becomes excessive -- either through blockage or as the body slowly loses its ability to absorb the liquid. In normal pressure hydrocephalus, excess CSF causes the ventricles to enlarge and press on other parts of the brain. That in turn causes damage to the parts of the brain responsible for memory, walking and bladder control.

NPH afflicts about 375,000 people in the United States, although some estimates go as high as 750,000. The average sufferer is over 60. Normal pressure hydrocephalus often goes undiagnosed or is misdiagnosed because the symptoms are similar to Alzheimer's disease and Parkinson's disease.

EARLY DIAGNOSIS IS KEY

"I describe it as what happens if you've got one bathroom in the house, and you shower every morning," said Debbi Fields, Executive Director of the National Hydrocephalus Foundation. "One morning you take a shower and see the water isn't draining as it should.

"The plumber can't get there for three or four days, but you still go in and take a shower every day. By the third day you go in, and you've got a problem. That, in essence, is NPH. The brain, as smart as it is, doesn't realize that there's a problem and just keeps on producing spinal fluid."

The symptoms of NPH generally come on very slowly and are often dismissed as part of aging. Sufferers of NPH may just try to adjust to gradual problems with memory and reasoning skills, balance and incontinence.

"You come up with excuses," Fields said. "I'm 70 years old; I'll get a cane. I'll buy Depends. I'll just have to make adjustments."

As the ventricles of the brain become more enlarged, the symptoms increase enough to concern the individual and his or her family -- but the underlying cause may still go undiscovered.

DIAGNOSING NPH

Dr. Michael Muhonen is Director of Neurosurgery and the Medical Director of the Children's Hospital Of Orange County Neuroscience Institute. He says one of the biggest problems in diagnosing NPH is the overlap of symptoms with other diseases such as Alzheimer's.

"The typical patient is elderly. They have the shuffling gait. They're incontinent of urine, and they have dementia," he said. "The problem is, when you become demented, you're often incontinent of urine. In Alzheimer's, when grandma or grandpa starts to get confused or forgetful, they chalk it up to Alzheimer's.

"Nursing homes are full of people who are demented that may actually have NPH."

A neurologist or neurosurgeon will examine the patient for the three main symptoms of NPH to aid in the diagnosis. In addition to being "wobbly," the sufferer may have what is called a magnetic gait -- taking short, shuffling steps as if their feet are stuck to the ground. The doctor will also learn if the patient has had brain trauma or has a tumor, factors that can contribute to the likelihood of NPH.

Diagnostic tools include a CT Scan to provide images of the ventricles, along with ultrasound or MRI. If those tools indicate that NPH may be present, further testing will be done to determine if the patient would be a good candidate for surgery to try to adjust the imbalance of cerebrospinal fluid in the brain.

The most commonly used test is a lumbar puncture where central nervous system fluid is drained from the patient's spine. A physical therapist will work with the patient, watching the gait and other symptoms before and after the lumbar puncture to see if there is improvement. The person's response to the spinal fluid drain is considered helpful in determining how much the patient might be helped by what is the main hope for sufferers of NPH -- an implanted shunt.

TREATING NPH

The most common treatment for NPH is the surgical insertion of a shunt, according to the Hydrocephalus Foundation. A shunt is an adjustable valve with a flexible tube placed in the brain to divert the flow of CSF into another part of the body where it can be absorbed -- usually, the abdomen. A neurosurgeon can implant the shunt during an operation that takes about an hour.

Though the shunting procedure has been used for a number of years, advances in the manufacture of shunts now give physicians much better control of the amount of fluid that is drained from the cavities of the brain.

Another procedure called endoscopic third ventriculostomy is sometimes used to treat hydrocephalus. The neurosurgeon makes a small hole in the bottom of the third ventricle, letting the cerebrospinal fluid drain.

"There are hundreds of anecdotal instances of people who have seen dramatic life changes from the shunt," Muhonen said. One of his patients was a pastor in California who became so impaired with dementia, incontinence and mobility problems that he was placed in a nursing home. After the shunting procedure, he was able to resume an independent lifestyle and even drive a car.

Shunt surgery is not a cure for NPH, and it does not always help with the symptoms, however. Some people's symptoms do not show improvement or may improve only temporarily. The increased risks for surgery in the elderly and possible complications from the shunt -- such as infection and bleeding -- make the surgery a case-by-case decision, Muhonen said.

Debbi Fields says she can personally attest to the successful use of the shunting procedure. She was "shunted" 22 years ago for hydrocephalus. She said the only time she really notices the device is when she washes her hair. If there is one message she could get across to sufferers of normal pressure hydrocephalus, it's that it's never too late to try to correct the condition.

Normal pressure hydrocephalus is a progressive disease. Support groups are encouraged for patients and family members, especially when the sufferer is not considered a good candidate for surgery.

Dr. Muhonen advocates inserting the shunt if he feels there is any chance the patient will benefit. The alternative to surgery is "essentially a death sentence," he said.

"Death is not the worst outcome," he said. "The worst outcome for these patients is that they're vegetative and totally dependent on other for care."