Normal Pressure Hydrocephalus: Recognizing Gait Issues, Cognitive Changes, and Shunt Treatment

Imagine waking up one day and noticing your walk has changed. Your feet feel stuck to the floor, like you’re walking through mud. You used to be able to climb stairs without thinking, but now you shuffle, take tiny steps, and worry you’ll fall. At the same time, you’re forgetting appointments, struggling to follow conversations, and sometimes losing control of your bladder. You tell yourself it’s just aging. But what if it’s not? What if this is normal pressure hydrocephalus - a treatable condition often mistaken for dementia or Parkinson’s?

What Exactly Is Normal Pressure Hydrocephalus?

Normal pressure hydrocephalus, or NPH, happens when cerebrospinal fluid (CSF) builds up in the brain’s ventricles. These are natural fluid-filled spaces that cushion the brain. In NPH, the fluid doesn’t drain properly, causing the ventricles to swell. But here’s the twist: the pressure inside the skull stays within the normal range - between 70 and 245 mm H₂O. That’s why it’s called “normal pressure.” It doesn’t feel like a brain tumor or a stroke. It creeps in slowly, like fog rolling in.

This condition mostly affects people over 60. About 0.4% of people in that age group have it, and among nursing home residents, that number jumps to nearly 6%. Yet, most doctors don’t test for it. A 2022 study found that up to 60% of NPH cases are misdiagnosed - often as Alzheimer’s, Parkinson’s, or just “old age.”

The real clue? The classic trio: trouble walking, memory problems, and bladder control issues. But here’s the catch: only about 30% of people have all three at once. Many only have one or two. That’s why it’s so easy to miss.

The Gait Problem: More Than Just Walking Slowly

If you notice someone starting to walk differently - feet dragging, wide stance, slow steps, or a sense that their feet are glued to the ground - that’s the hallmark of NPH. Doctors call it a “magnetic gait.” It’s not the same as Parkinson’s, where people freeze or tremble. NPH gait is more like wading through wet sand. You don’t lose strength; you lose coordination.

Studies show that 100% of confirmed NPH patients have this gait disturbance. It’s the most consistent sign. And it’s often the first to improve after treatment. One patient in a 2023 support group shared that after his shunt was placed, his 10-meter walk time dropped from 28 seconds to 12 seconds - in under two days.

Doctors use instrumented walkways to measure stride length, speed, and variability. A simple timed walk test - timing how long it takes to walk 10 meters - is often the first step in diagnosis. If the person walks slower than 0.8 meters per second, it raises a red flag.

Cognitive Changes: Not Just Forgetfulness

Memory loss in NPH isn’t like Alzheimer’s. You don’t forget your own name or your children’s faces. Instead, you struggle with executive function - planning, starting tasks, staying focused. You might forget why you walked into a room. You’ll repeat yourself. You’ll have trouble following a recipe or managing bills.

Neuropsychological testing shows that 85% of NPH patients have frontal-subcortical deficits. That means the brain’s “control center” isn’t working right. Tests like the Trail Making Test Part B and Digit Symbol Substitution Test pick up these issues. People with NPH often score poorly on tasks that require quick thinking or switching between mental tasks.

Unlike Alzheimer’s, where decline is steady and irreversible, NPH’s cognitive symptoms can bounce back - fast. After a successful shunt, many patients report clearer thinking within days. One woman said she could finally read the newspaper again after 18 months of giving up because she couldn’t follow the lines.

Shunts: The Treatment That Can Change Everything

The only treatment for NPH is surgery - a ventriculoperitoneal (VP) shunt. It’s a small tube placed in the brain’s ventricle, connected to another tube that runs down to the abdomen. A valve in between controls how much fluid drains. Think of it like a faucet that lets extra CSF drain into the belly, where the body absorbs it naturally.

The surgery takes about an hour under general anesthesia. Most people go home in 2 to 7 days. Recovery takes 6 to 12 weeks. But the payoff? For 70 to 90% of well-selected patients, symptoms improve significantly. Gait gets better first - often within 48 hours. Bladder control and cognition follow over weeks.

There are different types of shunts. Medtronic’s Strata® valve and Codman’s Hakim® valve are the most common. They’re programmable, meaning doctors can adjust the pressure setting non-invasively with a magnet. That’s huge - it means if the patient gets too much drainage and develops a headache, the valve can be tweaked without another surgery.

How Do You Know If a Shunt Will Work?

Not everyone with NPH symptoms is a good candidate. That’s why doctors don’t jump straight to surgery. They use a CSF tap test - removing 30 to 50 milliliters of spinal fluid with a needle in the lower back. Then they measure gait, balance, and cognition before and after.

If the person walks 10% faster or scores better on a cognitive test after the tap, they’re likely to respond to a shunt. A 2022 Cleveland Clinic study found this test predicts success with 82% accuracy. If the improvement is over 15%, the chance of shunt success jumps to 89%.

There’s also a newer tool: the iNPH Diagnostic Calculator app. It uses 12 clinical factors - like MRI findings, gait speed, and age - to predict shunt response with 85% accuracy. It’s becoming a standard part of the diagnostic workflow in major hospitals.

Why So Many People Are Misdiagnosed

NPH overlaps with other conditions. Alzheimer’s, Parkinson’s, vascular dementia - they all cause memory and movement problems. But the differences matter.

Alzheimer’s usually starts with memory loss and language trouble. Gait problems come late, if at all. Parkinson’s has tremors and stiffness. NPH has no tremor. Its gait is wide-based and magnetic. Vascular dementia often comes in steps - after a stroke or mini-stroke. NPH creeps in slowly.

Imaging helps. An MRI showing enlarged ventricles, periventricular white matter changes, and a “flow void” in the aqueduct (the narrow channel between ventricles) is highly suggestive. Evan’s index - the ratio of ventricle width to brain width - over 0.3 is a key diagnostic marker.

But here’s the problem: most primary care doctors don’t order MRIs for “slow walking.” They assume it’s aging. The average time from symptom onset to diagnosis? 14.3 months. By then, the brain may have started to change permanently.

Risks and Realities of Shunt Surgery

Shunts work - but they’re not magic. About 20 to 30% of patients don’t improve, even with a positive tap test. Why? Maybe the brain has already been damaged too long. Maybe there’s another condition mixed in - like early Alzheimer’s - which the shunt can’t fix.

Complications happen. Infection occurs in about 8.5% of cases. Shunt malfunction (blockage or over-drainage) affects 15% within two years. Subdural hematomas - bleeding between the brain and skull - happen in 5.7% of cases. Older patients, especially over 80, have higher infection rates.

Some people get headaches after surgery because too much fluid drains. Others develop nausea or dizziness. These are often fixable by adjusting the valve pressure. But it means follow-ups are critical - at 2 weeks, 6 weeks, 3 months, and 6 months after surgery.

What Happens After Surgery?

Success isn’t just about walking better. It’s about independence. A 2022 survey of 457 NPH patients found that 78% needed less help from caregivers after shunt surgery. 89% said they were satisfied with their treatment, even if they needed a revision.

Most patients notice improvement within 72 hours. Gait improves fastest. Bladder control follows in 2 to 4 weeks. Cognition takes longer - up to 3 months. But many report feeling “like themselves again.” One man said he started gardening again. Another took her first solo bus trip in two years.

Long-term data from Sweden shows that 68% of patients still had improved symptoms 20 years after surgery. But shunts don’t last forever. The average shunt lasts 6.3 years before needing adjustment or replacement.

The Future of NPH Diagnosis and Treatment

Researchers are working on better tools. A 2022 FDA-approved device, the Radionics® CSF Dynamics Analyzer, measures how well CSF drains - a key factor in predicting shunt success. Three clinical trials are testing blood or spinal fluid biomarkers that could diagnose NPH without a tap test.

Insurance is still a hurdle. In the U.S., 37% of patients face denials for CSF tap tests or external drainage procedures. Medicare covers shunt surgery, but not always the diagnostic steps. That delays care.

There’s growing collaboration between Alzheimer’s and Hydrocephalus Associations to create clearer guidelines for patients with mixed dementia - those who have both NPH and Alzheimer’s. The goal? Don’t miss the treatable part.

What Should You Do If You Suspect NPH?

If you or a loved one over 60 has:

• Progressive trouble walking - shuffling, wide stance, feeling stuck
• Memory issues that don’t match Alzheimer’s - trouble planning, starting tasks, not forgetting names
• Bladder control problems that started after walking changes

- ask for a neurology referral. Request an MRI and a CSF tap test. Don’t accept “it’s just aging.”

NPH is one of the few causes of dementia that can be reversed. You don’t need to live with it. The tools are here. The surgery works. The biggest barrier isn’t medicine - it’s awareness.