A Research Guide for
Normal Pressure Hydrocephalus

Diagnosis

Diagnosing NPH well is crucial, because it determines who is likely to benefit from surgery. It combines the clinical picture, brain imaging, and — importantly — tests that predict response to draining fluid.

The clinical picture

Diagnosis starts with recognizing the pattern: an older adult with an unexplained, symmetric walking disturbance, a frontal-subcortical pattern of thinking changes, and/or urinary urgency, whose other conditions do not fully explain the symptoms. A careful neurologic exam, with close attention to gait (often timed and videotaped to compare later), and cognitive testing, are the foundation.

Telling NPH apart from Alzheimer's and Parkinson's

Because NPH is treatable and the others largely are not, distinguishing them is worth real effort. No single feature is decisive, but the pattern usually points one way:

• NPH vs Alzheimer's disease. In NPH, walking trouble usually comes first and dominates, and the thinking problem is one of mental slowing and poor attention rather than dense forgetting; people typically still recognize family and places. In Alzheimer's, prominent memory loss usually comes first and the walking is normal until late. On the scan, Alzheimer's shows shrinkage of the memory structures (medial temporal lobes), whereas NPH shows the disproportionate ventricle enlargement, DESH pattern, and narrow callosal angle. The two frequently coexist, which is why cognition improves less reliably than gait after a shunt (a central finding of the 2025 PENS trial).
• NPH vs Parkinson's disease. Both cause a shuffling gait, but NPH's is broad-based and “magnetic” (feet stuck, wide stance), while Parkinson's is narrow-based with small steps, a stooped posture, reduced arm swing, tremor, and a good response to levodopa. NPH does not respond to Parkinson's medication, and its gait improves with fluid removal — a useful distinguishing test.
• NPH vs vascular ("small-vessel") disease. Strokes and white-matter disease can cause a similar gait and slowed thinking; MRI helps, and the two often overlap. Vascular changes that are heavy can limit how much a shunt helps, so they are weighed in the decision.

Ask your neurologist: "How confident are you that this is NPH rather than Alzheimer's, Parkinson's, or small-vessel disease — and what specifically points that way?"

What the office evaluation involves

The first visits usually combine a careful history with a focused examination. Your clinician will ask when each symptom started and how it has changed, with particular attention to the timeline of the walking problem relative to thinking and bladder changes, and to anything that might point to another cause. The exam includes watching you walk — often timing it and noting the stride width, shuffling, turning, and balance — and brief cognitive testing of attention, memory, and problem-solving. A bladder history is taken. A close family member's account is invaluable, since they often notice the gradual changes and falls most clearly. There is no need to prepare in any special way, but it helps to bring a list of your medicines, a summary of when symptoms began, and, if possible, a short video of the walking difficulty. From this picture, your clinician decides which tests — imaging and a tap test — will best answer whether this is treatable NPH.

Brain imaging

An MRI (or CT) of the brain is essential. In NPH it shows enlarged ventricles out of proportion to brain shrinkage — measured in part by the “Evans index.” Radiologists also look for a specific pattern called DESH (disproportionately enlarged subarachnoid space hydrocephalus) and a narrowed “callosal angle,” both of which support the diagnosis and help predict who will respond to a shunt. Imaging also helps rule out other causes such as strokes, tumors, or a blockage.

It helps to understand what the scan can and cannot tell you. The MRI is excellent at showing the structure — how large the ventricles are, the patterns (like DESH and the callosal angle) that favor NPH, and signs of other problems such as strokes or a blockage. What it cannot do by itself is prove that draining fluid will help you, because some people with NPH-like scans do not respond to a shunt, and some people with less dramatic scans do. That is why imaging is paired with the response to removing fluid (the tap test or drainage trial). Think of the scan as identifying who is a plausible candidate, and the fluid-removal test as showing who is likely to actually benefit — together they guide a careful, individualized decision.

Reading your scan: the numbers that matter

A few specific measurements show up in NPH reports, and knowing them helps you follow the conversation:

• Evans index above 0.3. This is the width of the front horns of the ventricles divided by the width of the skull at that level; a value above 0.3 defines enlarged ventricles and is part of the diagnostic criteria (international iNPH guidelines, 2005).
• Callosal angle (typically under about 90 degrees). Measured on a coronal MRI, a narrow (acute) callosal angle supports NPH over simple age-related shrinkage and helps predict a good shunt response.
• DESH pattern. “Disproportionately enlarged subarachnoid-space hydrocephalus” — tight, crowded grooves at the top of the brain alongside widened spaces lower down. It supports the diagnosis but is not present in every person who responds to a shunt.
• Opening pressure at or below 200 mm H2O. During the spinal tap, the measured spinal-fluid pressure is usually normal (at or below roughly 200 millimeters of water) — the “normal pressure” in the name.

Ask your neurologist: "What were my actual numbers — my Evans index, my callosal angle, and my opening pressure — and do they support the diagnosis?"

How walking is measured

Because gait is the key symptom — both for diagnosis and for predicting and judging treatment response — doctors measure it carefully and objectively rather than relying on impressions. You may be asked to walk a set distance (such as 10 meters) while it is timed, or to do a “timed up-and-go” (rise from a chair, walk a few meters, turn, return, sit), and the number of steps and turning may be counted. These walks are often videotaped so the team can compare your gait before and after fluid is removed, and before and after surgery. This objectivity matters: a clear, measured improvement in walking speed after a tap test is one of the strongest signs that a shunt will help, and it guards against being misled by hopeful but subjective impressions on either side.

The tap test and drainage trials

The single most useful predictor of whether surgery will help is seeing what happens when fluid is removed:

• The tap test (large-volume lumbar puncture): a doctor removes a substantial amount of CSF through a needle in the lower back (local anesthetic), and your walking (and sometimes thinking) is measured before and after, usually over a day or two. A clear improvement in gait strongly suggests a shunt will help.
• Extended lumbar drainage: if the tap test is inconclusive, a thin catheter may be left in place for a few days in the hospital to drain fluid continuously, giving a more sensitive test of response.
• Infusion or pressure studies are used in some centers to assess CSF dynamics.

A good response to these tests is reassuring and improves the odds that surgery will help; a poor response does not always rule out benefit but lowers the likelihood, and is weighed carefully.

Questions to ask your doctor

• Ask your neurologist: "What does my MRI show — is my Evans index above 0.3, is there a DESH pattern, and is my callosal angle narrow?"
• Ask your neurologist: "Should I have a tap test, and if it is unclear, extended lumbar drainage, to predict whether a shunt will help me?"
• Ask your neurologist: "How exactly will you measure my walking before and after the fluid is removed — will you time me and record a video?"
• Ask your neurologist: "Have you ruled out Alzheimer's, Parkinson's, stroke, and a spine problem as the main cause of my symptoms?"
• Ask your neurologist: "How many milliliters of fluid will you remove, and how long after the tap will you re-check my walking?"

Treatment

The main treatment for NPH is surgical: placing a shunt to drain excess fluid. Understanding what it involves, what it can realistically achieve, and its risks helps you make a confident, informed decision.

The shunt

A ventriculoperitoneal (VP) shunt is a thin, soft tube placed by a neurosurgeon. One end sits in a ventricle of the brain; the tube runs under the skin to the abdomen, where the excess CSF drains and is harmlessly absorbed. A valve controls the flow. Modern adjustable (programmable) valves can be re-set non-invasively (with a magnetic device in the clinic) to fine-tune drainage — increasing it if symptoms persist, or decreasing it to prevent over-drainage. (A lumboperitoneal shunt, draining from the lower spine, is an alternative in some cases.)

How the shunt helps — and its limits

The logic of a shunt is straightforward: NPH symptoms come from excess fluid stretching and pressing on the brain pathways for the legs, bladder, and aspects of thinking; draining that fluid relieves the pressure, and those pathways can recover function. That is why walking, which depends on pathways especially affected by the enlarged ventricles, tends to improve the most. The limits come from two sources. First, if pathways have been compressed for a very long time or are severely damaged, recovery may be incomplete — an argument for not waiting too long. Second, many older adults also have other brain conditions (especially Alzheimer's-type changes) that a shunt cannot treat; when those contribute heavily to the thinking problems, memory may improve little even as walking gets better. Understanding this helps set realistic, domain-by-domain expectations rather than hoping a shunt will reverse everything.

Why the PENS trial matters

For years, doubts lingered about whether shunting truly worked for NPH or whether improvements were placebo effects or natural fluctuation — in part because earlier studies could not ethically use a true sham surgery. The PENS trial cleverly addressed this: everyone received the shunt operation, but the adjustable valve was set either to genuinely drain fluid (“open”) or, in the comparison group, to a setting so high it effectively did not drain (a “placebo” setting) — and neither patients nor assessors knew which. This rigorous design showed that the people with truly working shunts had real, measurable improvement in walking, while thinking and bladder scores were not clearly better than the placebo setting in the short term. The takeaway is reassuring and clarifying: shunting genuinely helps gait in well-selected patients, and it is honest to expect the most benefit there. It is among the strongest pieces of evidence in the field and underpins modern, realistic counseling.

What to expect, and what the evidence shows

Walking often improves first and most, sometimes within days to weeks; cognition and bladder symptoms may improve more variably and gradually. The landmark PENS trial (2025) — a rigorous study comparing a working shunt to a “placebo” (effectively switched-off) valve setting — confirmed that an open shunt genuinely improves gait, while improvements in thinking (MoCA) and bladder symptoms were not clearly better than placebo in that short-term study. The practical message: expect the most reliable benefit in walking, hope for but do not assume improvement in thinking and bladder, and understand that comorbid conditions (like Alzheimer's changes) can limit cognitive gains.

What the numbers say about your odds

Realistic, sourced numbers help you weigh the decision honestly:

• Gait improvement after shunting: in carefully selected patients, roughly 60 to 80 percent show meaningful improvement in walking (AAN practice guideline, 2015, drawing on multiple cohort studies), with the best odds in those who clearly improved after the tap test.
• The tap test is specific but not very sensitive: a clear positive response strongly predicts benefit (positive predictive value commonly reported around 70 to 90 percent), but a negative tap test does not rule out a shunt-responsive patient. That asymmetry is why a negative tap does not end the conversation.
• Extended lumbar drainage is more sensitive: reported sensitivity is often above 80 percent, which is why the several-day drainage trial is used when suspicion stays high despite a negative tap test (international and Japanese iNPH guidelines).
• Cognition and bladder respond less reliably than gait — the central, honest finding confirmed by the placebo-controlled PENS trial (2025).

These figures are ranges from the published literature, not a promise about any one person; your own tap-test response and imaging move your personal odds up or down. Ask your neurosurgeon: "Given my specific tap-test result, where do I fall in that 60-to-80-percent range?"

How we know shunting works: the evidence, dated

It helps to see that the advice in this guide rests on decades of accumulating research, not opinion. A brief, dated timeline:

• 1965 — Hakim and Adams first described NPH as a syndrome of gait, thinking, and bladder decline with normal spinal-fluid pressure that could improve when fluid was drained — the original insight that this dementia could be reversible.
• 1990s — The Dutch Normal-Pressure Hydrocephalus Study compared valve pressure settings and helped establish how shunt response is measured.
• 2005 — International iNPH guidelines (Relkin and colleagues) defined the “possible” and “probable” diagnostic categories and anchored the Evans index above 0.3 as an imaging threshold.
• Around 2010 — The Japanese SINPHONI study described the DESH imaging pattern prospectively as a predictor of shunt response.
• 2015 — SINPHONI-2, a Japanese randomized trial, supported lumboperitoneal shunting; the same year the American Academy of Neurology (AAN) published a practice guideline concluding that shunting probably improves gait in carefully selected patients.
• 2021 — The Japanese Society iNPH guidelines — the most extensive evidence base in the field — were updated to their third edition.
• 2025 — The PENS trial, published in the New England Journal of Medicine, used a “sham” valve setting to deliver the first truly placebo-controlled proof that an open shunt improves walking — while honestly showing that thinking and bladder scores were not clearly better than placebo in the short term.

The through-line across sixty years of study is consistent and is the honest headline of this guide: in the right, carefully selected person, draining the fluid genuinely improves walking — and the 2025 trial removed the last major doubt about whether that benefit was real.

What the surgery and hospital stay involve

Shunt placement is a relatively short operation done under general anesthesia by a neurosurgeon. You will receive a single dose of a preventive intravenous antibiotic shortly before the incision — for CSF shunt surgery, surgical-prophylaxis guidelines (ASHP/IDSA, 2013) recommend cefazolin 2 g IV (3 g if you weigh 120 kg or more) within 60 minutes of the start, with vancomycin (about 15 mg/kg IV) substituted or added if you have a serious penicillin allergy or a known resistant organism. The surgeon makes a small opening in the skull to pass the upper end of the tube into a ventricle, tunnels the tubing under the skin down to the abdomen, and places the valve (usually behind the ear). Most people stay in the hospital a short time and recover from the operation itself fairly quickly. In the days and weeks afterward, the team checks the incision sites and the shunt, watches for over- or under-draining, and may adjust the valve setting in the clinic. Walking often begins to improve in the first weeks, and physical therapy helps you regain strength and confidence after what may have been a long period of unsteadiness. It is normal to have follow-up imaging and several visits as the valve is fine-tuned to your response.

Preparing for surgery and the hospital stay

A little preparation makes the operation and recovery smoother:

• Medication review. Bring a complete list. Blood thinners (warfarin, DOACs such as apixaban or rivaroxaban, and antiplatelet drugs like clopidogrel or aspirin) raise bleeding risk and are often paused before surgery on a specific schedule — never stop them on your own. Ask your neurosurgeon: "Which of my medications should I stop before surgery, and exactly how many days before?"
• Sedating medicines. Because fall risk is already high in NPH, review any sedatives, sleep aids, opioids, or first-generation antihistamines with your team — these add to unsteadiness.
• The shunt ID card. After surgery you will get a card listing your valve model and pressure setting. Keep it in your wallet; you will need it before any MRI and at airport security.
• Plan the recovery. Arrange help at home for the first days, set up a physical-therapy referral in advance, and remove trip hazards before you come home so you return to a safer environment.

Risks of surgery

Shunt surgery is generally safe but has real risks that must be weighed: bleeding around the brain (including subdural hematoma, more likely with over-drainage), infection, shunt blockage or malfunction (which may require revision), over-drainage (causing headaches, especially when upright) or under-drainage (persistent symptoms), and the usual risks of surgery and anesthesia. The PENS trial found more bleeding and positional headaches in the actively-shunted group — but also more falls in the placebo group, reflecting untreated gait problems. Adjustable valves help manage over- and under-drainage by allowing fine-tuning afterward.

When other conditions are also present

It is common for an older adult to have NPH and some degree of Alzheimer's-type or blood-vessel-related brain changes at the same time — the brain can have more than one thing going on. This matters for setting expectations: when these other conditions contribute significantly to the thinking problems, a shunt may improve walking nicely while memory improves only a little. It does not usually mean a shunt is pointless — regaining safer, more independent walking and reducing falls is genuinely valuable on its own. Your team may evaluate for these coexisting conditions (sometimes with additional tests) to give you a clearer picture of what to expect. The honest framing is: treat the treatable NPH component for the real benefits it offers, especially to walking, while understanding and separately addressing whatever else is contributing. If Alzheimer's disease is diagnosed alongside NPH, the standard Alzheimer's medicines — for example, donepezil (per its FDA label, 5 mg once daily, increased to 10 mg) or memantine (titrated up to 10 mg twice daily) — treat that component; they do not treat the hydrocephalus, but managing both conditions gives the fullest picture of benefit. Ask your neurologist: "If I have some Alzheimer's changes too, should we treat that separately from the shunt?"

Living with a shunt

A shunt is a permanent, generally low-maintenance implant, and most people live normally with one. A few practical points help: the valve and tubing are under the skin and usually not visible or bothersome, and you can resume normal activities as your team advises after recovery. If you have an adjustable (programmable) valve, strong magnetic fields — including MRI scanners — can sometimes change its setting, so always tell any clinician (especially before an MRI) that you have a programmable shunt, and your team will check and reset the valve afterward if needed. Keep a record of your shunt and valve model. Over the years, shunts can occasionally block, disconnect, or need the valve re-adjusted, so report any return of symptoms or new headaches and keep your follow-up appointments. Knowing the signs of a shunt problem — and that they are treatable — lets you live confidently rather than anxiously with the device. There are clear stop rules after a shunt: if you develop a severe headache that is worse when upright, new drowsiness or confusion, repeated vomiting, fever with a stiff neck, or a return of your original walking, thinking, or bladder symptoms, treat it as a possible shunt problem (over-drainage with bleeding, blockage, or infection) and seek urgent care rather than waiting — these are the signs that the valve setting must be changed, or the shunt checked or revised.

Who is a good candidate

The best candidates typically have prominent gait problems, a clear improvement after the tap test or lumbar drainage, supportive imaging, symptoms that are not too long-standing or severe, and limited competing conditions. Careful selection by an experienced team is what separates good outcomes from disappointment. Being older is not by itself a barrier; overall health and the likelihood of benefit matter more. As a rule of thumb: if your walking clearly improved after the tap test, a shunt is typically considered the best option, because that response is the strongest single predictor of benefit; if the tap test was negative, doctors may still consider an extended lumbar drainage trial, because it is a more sensitive test.

Questions to ask your doctor

• Ask your neurosurgeon: "Based on my tap-test response and my imaging, what is your best estimate of how much my walking will improve with a shunt?"
• Ask your neurosurgeon: "Which of my symptoms are most likely to improve, and which ones should I not expect a shunt to fix?"
• Ask your neurosurgeon: "What are my specific risks of bleeding and infection, and how many NPH shunts does your team place each year?"
• Ask your neurosurgeon: "Will I get an adjustable (programmable) valve, what opening pressure will you start at, and how will you adjust it afterward?"
• Ask your neurosurgeon: "What is the plan if the shunt does not help — how will you check whether it is working before we conclude it failed?"
• Ask your surgeon: "Would a second opinion at a dedicated NPH center change anything about my case?"

Living with NPH, Recovery & Trials

Whether or not you have surgery, attention to safety, rehabilitation, and follow-up makes a real difference. Here is what to expect and how research is advancing.

The overall outlook

Putting it together, the outlook in NPH is genuinely more hopeful than for most causes of late-life cognitive and walking decline, with important caveats. For a person carefully selected — prominent walking trouble, a clear response to the tap test, supportive imaging, and not too much competing disease — a shunt can restore safer, more independent walking and reduce falls, sometimes dramatically, and this benefit has now been confirmed in a rigorous placebo-controlled trial. Thinking and bladder symptoms may improve too, but less reliably, and coexisting conditions can limit the cognitive gains. Surgery carries real but generally manageable risks, and the shunt is a lifelong device needing follow-up. For those who are not candidates, an active supportive plan still protects quality of life. The single most important message is that NPH is worth recognizing and evaluating, because for the right person, it is one of the rare treatable causes of these symptoms — and acting earlier tends to work better.

After a shunt: recovery and follow-up

Recovery from shunt surgery is usually quick, but the benefit to walking can continue to develop over weeks. Physical therapy helps rebuild strength, balance, and confidence after what may have been a long period of unsteady walking. Expect regular follow-up to check the shunt, possibly adjust the valve, and monitor for over- or under-drainage (report new or positional headaches, increasing confusion, or worsening symptoms). Shunts can need adjustment or, occasionally, revision over time, so ongoing specialist care is part of the plan.

The role of rehabilitation

Surgery removes the obstacle to better walking, but rehabilitation is often what turns that potential into real-world function. After months or years of unsteady, cautious walking, muscles weaken, balance reflexes get rusty, and fear of falling can itself limit movement. Physical therapy after a shunt — and sometimes before, to optimize starting condition — rebuilds strength, balance, and confidence, and teaches safe strategies for turning, standing, and navigating obstacles. Occupational therapy helps with daily tasks and home safety. Because the gait improvement from a shunt can keep developing over weeks, pairing it with consistent therapy gives the best functional result. The two work in synergy: the shunt removes the fluid pressure that was holding walking back, and rehabilitation rebuilds the strength, balance, and confidence needed to actually use that recovered capacity — the combined benefit is consistently greater than either surgery or therapy alone. Ask your team: "Can you set me up with physical therapy before and after the shunt so the two reinforce each other?" Approach recovery as an active process rather than waiting passively for the shunt to “do everything.”

If surgery is not chosen

If you are not a candidate for surgery, or choose not to have it, care focuses on safety and quality of life: fall prevention (physical therapy, home safety, mobility aids), managing bladder symptoms, supporting thinking and daily function, and treating any coexisting conditions. Repeated spinal taps are not an effective long-term treatment, and no medication reliably treats NPH, so the focus is supportive.

Choosing not to have surgery is a legitimate decision, especially when the likelihood of benefit is uncertain, surgical risks are high, or it does not fit a person's goals — and it does not mean nothing can be done. A strong, active supportive plan can meaningfully protect quality of life: a physical therapy program to maintain strength and reduce falls, the right mobility aids, a home-safety review, sensible management of urinary urgency, and attention to treating other conditions (vascular risk, mood, sleep) that affect function. It is also reasonable to revisit the surgical question over time, because candidacy can change — for example, if walking trouble becomes more clearly the dominant problem. The key is that “no surgery” should still mean “active, thoughtful care,” not being left without support.

If the shunt doesn't seem to help

Sometimes a shunt does not produce the hoped-for improvement, and it is important to know this is not necessarily the end of the road. The first step is to make sure the shunt is actually working — it can be blocked, disconnected, or set at a pressure that is draining too little, all of which are checkable and often fixable (an adjustable valve can be re-set in the clinic, or imaging can look for a problem). If the shunt is working well but symptoms persist, it may mean that coexisting conditions (like Alzheimer's or vascular disease) are driving the symptoms, or that the disease was too advanced to fully reverse. Your team will work through these possibilities methodically. So before concluding a shunt “failed,” ask whether it is functioning correctly and whether the valve setting should be adjusted — a simple change sometimes unlocks the benefit.

What to expect over time

Untreated, NPH tends to progress gradually, with worsening walking, thinking, and bladder control and an increasing risk of falls and loss of independence. Treated successfully, many people regain meaningful function, especially walking — though coexisting conditions and the durability of benefit vary, and some improvement can fade over years. This is why timely diagnosis and treatment, before symptoms become severe and entrenched, generally give the best results.

A realistic picture of the long term: after a successful shunt, the early gains in walking are often the most noticeable, and continued physical therapy helps cement them. Over the following years, several things can influence how things go — the shunt itself can occasionally block or need its valve adjusted (so ongoing follow-up matters), and any coexisting conditions like Alzheimer's or vascular disease continue on their own course and can gradually affect thinking even if the NPH component is well treated. None of this means a shunt “wears off” for everyone; many people maintain meaningful benefit. But it does mean NPH care is ongoing rather than one-and-done, and that keeping up with follow-up, rehabilitation, and overall brain and vascular health gives the best long-term outcome.

The long view: what the first year and beyond can look like

Setting expectations across time helps you plan and judge progress:

• First days to weeks after a shunt: walking often begins to improve; this is the domain most likely to respond, per the 2025 PENS trial. Report any positional headache promptly (possible over-drainage).
• First 3 months: most of the early gait gain is usually visible, the valve is fine-tuned in steps, and physical therapy consolidates the improvement. Objective re-timing of your walking around this point tells you how much you have gained.
• First year: many people maintain meaningful benefit; ongoing follow-up watches for shunt problems and adjusts the valve as needed.
• Years 3 to 5 and beyond: benefit can be durable, but some may fade — because the shunt can occasionally block or need adjustment, and any coexisting Alzheimer's or vascular disease continues on its own course (Japanese iNPH guidelines, 2021; long-term cohort studies). This is why NPH care is ongoing, not one-and-done, and why treating earlier tends to work better.

Ask your neurosurgeon: "At what point after surgery will we formally re-measure my walking to see how much I've gained?"

Falls: a central, preventable risk

Falls deserve special attention in NPH because the walking problem makes them common, and a serious fall (a hip fracture or head injury) can be devastating — sometimes more immediately harmful than the underlying condition. Whether or not surgery is planned, fall prevention is a priority: a physical therapy assessment for balance and strength, appropriate use of a cane or walker (fitted and trained, not improvised), removing home hazards (loose rugs, clutter, poor lighting), installing grab bars and railings, sensible footwear, and managing the urinary urgency that prompts rushed, risky trips to the bathroom. Treating NPH successfully often reduces falls by improving gait, but in the meantime — and for those who do not have surgery — these practical measures protect against one of the condition's most dangerous consequences.

Clinical trials and research

Research in NPH is active, focused on better predicting who will benefit and refining surgery. The trials below are real studies with their ClinicalTrials.gov registry numbers and status as of July 2026; always confirm current status and eligibility on ClinicalTrials.gov or with your specialist, because trial status changes over time.

• The PENS trials (Johns Hopkins) used a placebo (sham) valve setting to rigorously test whether shunting truly works. The pilot (NCT03350750, completed 2021) established the method, and the larger efficacy trial (NCT05081128, active/not recruiting, primary completion estimated May 2027) is the landmark evidence confirming the gait benefit reported in NEJM in 2025.
• ENDOVEST (NCT06488248, recruiting as of July 2026; University Hospital Basel) is a randomized trial comparing endoscopic third ventriculostomy against a VP shunt in iNPH — testing whether a less-invasive operation can match shunting.
• The CereVasc eShunt program is testing a minimally invasive, catheter-delivered ("endovascular") way to divert spinal fluid without open shunt surgery: a US pilot study (NCT05232838) and the pivotal STRIDE study (NCT06498960), both active/not recruiting as of July 2026.
• NPH-OPTIMIZE (NCT07427836, recruiting as of July 2026; IRCCS Milan) is an observational study combining spinal-fluid biomarkers, cognitive-motor testing, and neuroimaging to better select surgical candidates — part of the effort to predict who truly benefits.
• The DRAIN trial (NCT04975269, completed 2024; Uppsala University Hospital) was a double-blind randomized test of the drug acetazolamide in iNPH — important because it directly studies the one medication sometimes tried, which remains unproven as a substitute for shunting.
• A randomized study compared adjustable gravitational versus adjustable differential-pressure valves in iNPH (NCT04434053; Prague), part of the ongoing effort to reduce over-drainage — its registry status is listed as unknown/older as of July 2026, so confirm before relying on it.
• An earlier European multicenter study on predicting shunt outcome in iNPH (NCT00874198) helped build the evidence for imaging and tap-test predictors.
• A multi-omics study of prognostic factors for VP shunting in iNPH (NCT04998175, recruiting as of July 2026; Zhejiang University) is looking for biological markers that predict who responds.
• A study of how a depletive lumbar puncture and shunt surgery affect bladder symptoms in NPH (NCT03877107) focuses on the urinary part of the triad specifically; its registry status is listed as unknown as of July 2026.
• Other work is refining imaging and biomarker predictors (DESH, callosal angle, and combining them with the tap test) and studying valve settings and rehabilitation after surgery to improve outcomes and reduce complications.

Questions to ask your doctor

• Ask your neurosurgeon: "What follow-up and valve checks will I need after the shunt, and exactly which symptoms should make me call you or go to the ER?"
• Ask your doctor: "If I choose not to have surgery, what is the plan to keep me walking safely and prevent falls?"
• Ask your neurosurgeon: "How durable is the walking benefit likely to be in my case, and what could cause it to fade over the years?"
• Ask your neurologist: "Are there any clinical trials at accredited centers that I might be eligible for?"

Support & Resources

Below are specialty centers, support organizations, a note on family planning, a glossary, what does not work, and the sources behind this guide.

Getting the right evaluation

Because NPH is treatable but easily missed, getting to the right specialists matters. Evaluation usually involves a neurologist (often with expertise in movement or cognitive disorders) and a neurosurgeon, ideally at a center experienced in NPH that can perform tap tests, lumbar drainage, and shunt surgery and manage adjustable valves. If walking decline and possible NPH are suspected, ask your doctor for a referral; do not assume that gait and memory changes are simply unavoidable aging.

Living with the bladder and walking symptoms day to day

While pursuing diagnosis and treatment, practical steps ease daily life. For bladder urgency: scheduled bathroom trips, easy-access clothing, a clear and well-lit path to the toilet (and a bedside option at night), and managing fluids sensibly can reduce accidents and the rushed trips that cause falls; ask about treatments for overactive bladder, but be aware some bladder medicines can affect thinking, so choices should be made with the cognitive picture in mind. For example, the beta-3 agonist mirabegron is a non-anticholinergic option (its FDA label starts at 25 mg once daily, increased to 50 mg if needed) that avoids the memory side effects anticholinergic bladder drugs such as oxybutynin (commonly 5 mg tablets) can cause; discuss the choice with your doctor, and report new confusion or a rise in blood pressure. For walking: use a properly fitted cane or walker if recommended, take time turning (a common moment for falls), and keep moving safely to maintain strength. For thinking: routines, reminders, and reducing clutter and distractions help. These measures are valuable both before treatment and for anyone who does not have surgery, and they preserve dignity and independence while the bigger decisions are made.

For caregivers

Caregivers are central to recognizing NPH and supporting treatment. Some of the most valuable help: notice and describe the pattern (especially walking changes and falls), keep notes and even short videos of the gait to show the team, get to appointments and the tests that require timing and observation, support safety at home (reduce fall hazards, manage the bladder symptoms with dignity), and after surgery help with physical therapy and watch for warning signs (new or positional headaches, increasing confusion). Encourage independence and patience — recovery of walking can take time — and look after your own wellbeing too.

Two contributions from caregivers are especially powerful. First, recognition: families often notice the gradual walking decline and falls before anyone names NPH, and raising the question — “could this be treatable normal pressure hydrocephalus?” — can set the whole evaluation in motion. A short phone video of the person walking and turning, taken before and again after a tap test, is genuinely useful objective evidence for the team. Second, vigilance after surgery: knowing the warning signs of shunt problems (new or worse headache especially when upright, increasing confusion or sleepiness, fever with a stiff neck, or a return of symptoms) and acting on them promptly can prevent serious complications. Beyond these, the everyday support — getting to appointments, encouraging therapy, keeping the home safe — carries the recovery. And caregivers should protect their own health and seek support; this is a demanding role, and resources exist for you as well.

A note on family planning

Idiopathic NPH is a condition of older adults, so pregnancy is rarely relevant to it. (Hydrocephalus from other causes can occur in younger people, and management of CSF shunts in pregnancy is a specialized topic handled by the neurosurgery and obstetric teams.) For the typical older patient with iNPH, the practical priorities are mobility, fall prevention, and cognition rather than reproductive considerations.

Mountain West / Utah

• University of Utah Health — Neurosurgery and Neurology (Salt Lake City): evaluation for NPH including tap testing, lumbar drainage, and shunt surgery with adjustable valves; appointments via University of Utah Health (801-585-7575).
• Intermountain Health neurosciences — neurology and neurosurgery services across the Wasatch Front and Intermountain West.
• George E. Wahlen VA Medical Center (Salt Lake City) — neurology and neurosurgery for eligible veterans.
• Physical therapy and fall-prevention programs — important before and after treatment.

Making the decision well

Deciding whether to have a shunt is a personal choice best made with clear information and the right team. Helpful steps: ask for your objective results — how much your walking improved with the tap test, and what your imaging shows — since these drive the odds of benefit. Ask which of your symptoms are most likely to improve and which may not, and what the specific risks are for you. Consider a second opinion at an experienced NPH center if you are unsure. Weigh the potential gains (especially regaining safer, more independent walking and reducing falls) against the surgical risks and your overall health and goals. Bring a family member to appointments, write down questions, and take the time you need — while remembering that treating earlier, before symptoms are severe and long-standing, tends to give better results. There is rarely a single “right” answer; the goal is a decision that fits your situation and values.

Finding an experienced center

Outcomes in NPH depend heavily on careful selection and an experienced team, so where you are evaluated matters. Look for a center that can do the full workup — neurology and neurosurgery working together, with the ability to perform a tap test and extended lumbar drainage, supportive imaging interpretation, objective gait assessment, and shunt surgery with adjustable-valve management and good follow-up. Academic medical centers, comprehensive neuroscience programs, and hospitals recognized for hydrocephalus care are good places to start; the Hydrocephalus Association maintains resources and can help you locate experienced programs. If your initial evaluation is uncertain or you are told nothing can be done, a second opinion at such a center is reasonable, because the difference between a thorough and a cursory workup can be the difference between missing and finding a treatable condition.

National organizations

• Hydrocephalus Association (hydroassoc.org) — NPH-specific education, support, a helpline, and a center-locator; a leading resource for patients and families.
• National Institute of Neurological Disorders and Stroke (NINDS) (ninds.nih.gov) — trustworthy information on NPH.
• American Association of Neurological Surgeons (AANS) patient information (aans.org).
• ClinicalTrials.gov — searchable registry of NPH studies.

International access

NPH is recognized and treated worldwide, and shunt surgery is widely available in countries with neurosurgical care. The condition has been especially studied in Japan, which has published detailed national guidelines for iNPH, and international guidelines (developed with groups including the Hydrocephalus Association) and the American Academy of Neurology practice guideline inform care globally. Access to advanced diagnostic testing (lumbar drainage, infusion studies) and to experienced NPH centers varies by region; where specialized care is limited, the priority is recognizing the condition and referring to a center that can perform proper selection and surgery.

The core approach is similar across countries: recognize the gait-predominant syndrome with enlarged ventricles, confirm a response to removing fluid, and offer shunting to well-selected patients. Some differences exist — for example, lumboperitoneal shunting (draining from the lower spine rather than the brain) is used more commonly in Japan, and the availability of the most advanced diagnostic tests and adjustable-valve technology differs by health system. Wherever you are, the most important steps are the same and within reach: have the possibility of NPH considered when walking decline is unexplained, get to a center that can do a proper workup, and weigh treatment based on your individual response to the tap test and your overall health. The transformation a shunt can bring to walking applies regardless of country, for the right patient.

Using organizations and information wisely

The organizations listed here offer more than information: the Hydrocephalus Association in particular provides NPH-specific education, a helpline, peer support, and help locating experienced centers — valuable because NPH care depends so much on getting to the right team. When researching online, favor established, non-commercial sources (the organizations here, the NIH/NINDS, and major academic centers), and be skeptical of anything promising a quick cure or a non-surgical “fix,” since the only treatment with proven benefit is shunting in selected patients. Bring what you read — especially about tests, surgery, or trials — to your own neurologist or neurosurgeon to check how it applies to your situation. A trusted specialist plus a reputable patient organization is usually the best combination, giving you both expert, individualized guidance and the practical, lived-experience support that helps families navigate the journey.

Costs and coverage at a glance

Most people with NPH are 65 or older, so Medicare is the usual payer. For 2026, the Part A inpatient hospital deductible is $1,736 per benefit period (this covers the hospital stay for shunt surgery), and the Part B annual deductible is $283, after which Part B typically pays 80% and you pay the remaining 20% coinsurance for the neurosurgeon, anesthesia, outpatient MRI, the tap test, and follow-up valve-adjustment visits (figures per CMS, announced November 2025; current as of July 2026). A Medigap (supplemental) plan can cover much of that 20% and the deductibles; Medicare Advantage plans bundle costs differently, so confirm your surgeon and hospital are in network. Private insurers usually cover shunt surgery as medically necessary but often require prior authorization. If you are under 65 or uninsured, ask the hospital’s financial counselor about assistance, and contact the Hydrocephalus Association (888-598-3789) for navigation help. Programmable (adjustable) valves cost more than fixed valves but can spare the cost and risk of a second operation to change the pressure setting.

What the diagnosis and treatment cost — a plain-language appendix

NPH is a procedure-heavy condition, so most of the cost comes from imaging, the fluid-drainage tests, and surgery rather than from medications. The figures below are rough US estimates for 2025–2026 to help you plan and ask the right questions; they are not quotes. Two very different numbers exist for almost everything: the hospital’s list/charge price (high, and rarely what anyone actually pays) and the Medicare-approved amount (much lower, and the basis for what most older patients owe). What you pay depends on your insurance, your deductibles, and whether providers are in-network. Always ask for a written cost estimate in advance.

Estimates compiled from published US charge data and Medicare fee-schedule patterns; Medicare deductible and coinsurance figures are from CMS for 2026 (announced November 2025). Your actual cost will differ — use these only to frame the conversation.

The coverage path, step by step

• If you are 65 or older (most NPH patients): Medicare is the usual payer. The 2026 Part A inpatient hospital deductible is $1,736 per benefit period (this covers the surgery admission and any inpatient ELD trial), and the Part B annual deductible is $283, after which Part B pays 80% and you pay 20% coinsurance for the surgeon, anesthesia, outpatient MRI, the tap test, and follow-up valve-adjustment visits. Shunt surgery is covered under Medicare’s surgical (Part A inpatient) benefit, so it is not something you have to pay for out of pocket beyond the deductible and coinsurance.
• A Medigap (supplemental) plan can cover most or all of the 20% coinsurance and the deductibles — often the difference between a large bill and a small one for shunt surgery.
• Medicare Advantage plans bundle costs differently and use networks and prior authorization; before scheduling, Ask your plan: "Is my surgeon, my hospital, and this procedure covered, and do you require prior authorization?"
• Private insurance usually covers shunt surgery as medically necessary but typically requires prior authorization; your neurosurgeon’s office documents the gait-predominant picture, the enlarged ventricles (Evans index above 0.3, DESH), and the positive tap-test response to support medical necessity.
• If you are under 65 or uninsured: ask the hospital’s financial counselor about charity care and payment plans, and contact the Hydrocephalus Association (888-598-3789) for navigation help. If NPH causes significant disability, you may qualify for Social Security Disability Insurance, which brings Medicare after a waiting period.

Two worked examples of what you might actually pay

These illustrate how the pieces add up. They are simplified estimates for 2026, not quotes, and assume in-network care.

• A Medicare patient with a Medigap plan. The workup (MRI, tap test, neuropsychological testing) and the shunt surgery run through Part A and Part B; the patient owes the $1,736 Part A deductible and the $283 Part B deductible, and a good Medigap plan covers most of the 20% coinsurance — so the out-of-pocket total is often in the low $2,000 range rather than the tens of thousands the hospital charges.
• A patient on Medicare with no supplement. The same care leaves the patient responsible for the $1,736 inpatient deductible plus 20% of the Part B-covered surgeon, anesthesia, imaging, and tap-test charges — which can add several thousand dollars more (for example, roughly $1,000 to $4,000 in coinsurance), underscoring why a supplement or a Medicare Savings Program is worth exploring before surgery.

A shunt emergency (ER visit and imaging for a suspected over-drainage bleed or infection) is covered like any emergency, but an out-of-network ambulance or ER can generate a surprise bill of $1,000 or more — another reason to keep your shunt ID card and know which hospital your team uses. Ask your team: "If I have a shunt emergency, which ER should I go to so my neurosurgery team can see me?"

What does not work

Being clear about ineffective approaches prevents wasted effort and false hope. Medications do not reliably treat NPH — a carbonic anhydrase inhibitor such as acetazolamide (whose FDA label lists oral doses of 250 mg up to 1 g per day for other conditions) has been tried to reduce CSF production, and is sometimes used only as a brief temporizing trial period while surgery is arranged; it is not an effective or durable treatment for NPH and should not delay proper evaluation. Repeated spinal taps are useful for diagnosis (the tap test) but are not a long-term treatment. Endoscopic third ventriculostomy (ETV), a surgery effective for some other forms of hydrocephalus, is generally not effective for idiopathic NPH. And no supplement or alternative therapy treats NPH. The one intervention with proven benefit is CSF shunting in appropriately selected patients.

Where each recommendation comes from

So you can see this guide is sourced rather than opinion, here is where the main points come from, with dates:

Key sources

This guide draws on the primary literature and major guidelines. Key dated sources:

• Hakim & Adams (1965) — the original description of NPH as a potentially reversible syndrome.
• International iNPH guidelines, Relkin and colleagues (2005) — diagnostic categories and the Evans index above 0.3.
• SINPHONI (around 2010) and SINPHONI-2 (2015) — Japanese studies of the DESH pattern and of lumboperitoneal shunting.
• American Academy of Neurology (AAN) practice guideline (2015) — shunting probably improves gait in selected iNPH; tap-test and imaging predict response.
• Japanese Society iNPH guidelines, third edition (2021) — the most extensive iNPH evidence base.
• PENS pilot (NCT03350750, completed 2021) and PENS efficacy trial (NCT05081128; NEJM 2025) — placebo-controlled (sham-valve) confirmation of gait benefit.
• ClinicalTrials.gov registry data (trial identifiers and status verified as of July 2026) and standard neurosurgical/neurology references on the Evans index, DESH, callosal angle, tap test, and lumbar drainage.
• Centers for Medicare & Medicaid Services (CMS) — 2026 Part A and Part B deductible and coinsurance figures (announced November 2025).

This guide is educational and is not a substitute for advice from your own medical and surgical team.