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Normal-Pressure Hydrocephalus (NPH): A Treatable Cause of Dementia and How It's Diagnosed

If your loved one has developed trouble walking, foggy thinking, or new bladder problems, it may not be ordinary dementia. Normal-pressure hydrocephalus (NPH) is a buildup of cerebrospinal fluid in the brain's ventricles that can mimic Alzheimer's or Parkinson's — and it's one of the few potentially reversible causes of dementia when caught early. This guide explains what NPH is, why it happens, how doctors confirm it, and how to advocate for the right testing.

Key points

  • NPH is a potentially reversible cause of dementia, especially when caught early — don't assume the symptoms are simply aging.
  • The classic triad is gait trouble (shuffling, feet feeling 'stuck'), cognitive decline, and urinary incontinence; not everyone shows all three, and walking is usually first.
  • Most cases in older adults are 'idiopathic' (no known cause); 'secondary' NPH can follow head injury, infection, tumor, or brain bleeding.
  • NPH is uncommon — roughly 0.2% of people in their 60s — but the figure rises to about 5–6% in people over 80, where mixed dementia (NPH plus Alzheimer's or vascular disease) is also more likely.
  • Diagnosis combines symptoms, brain imaging (MRI/CT) showing enlarged ventricles, and a CSF tap test; a cisternogram can add information about fluid flow.
  • Treatment is a surgical shunt that drains excess fluid; it can dramatically improve walking and bladder control and sometimes thinking, but isn't right for everyone.
  • Always ask the clinician to rule out other reversible causes — vitamin B12 deficiency, thyroid problems, chronic subdural hematoma, and medication side effects.
  • Advocate with a symptom log, a request for a neurology referral, and the phrase 'potentially reversible.'

Understanding the situation

Picture the brain as a sponge cushioned by a clear, watery fluid called cerebrospinal fluid (CSF). Normally this fluid circulates around the brain and spinal cord and is reabsorbed into the bloodstream. In NPH, the fluid stops draining properly and pools inside the brain's hollow spaces (ventricles), stretching them like a slowly inflating balloon. Teepa Snow describes it as something gradually expanding inside the skull, pressing brain tissue against the bone until cells are damaged. The name 'normal-pressure' comes from the fact that the fluid pressure measured during a spinal tap is often within the normal range — yet harm still occurs because the fluid isn't circulating correctly. This produces the hallmark 'classic triad': (1) trouble walking — a shuffling, unsteady, magnetic gait where the feet feel 'stuck' to the floor or hard to lift; (2) cognitive decline — memory lapses, slowed thinking, and trouble with attention; and (3) urinary incontinence — urgency, frequency, or accidents. Symptoms often build over weeks to months, and not everyone shows all three; the walking change is usually first and most obvious.

Why does it happen? In most older adults no clear cause is ever found, and this is called 'idiopathic' NPH (iNPH) — the most common form. Sometimes NPH is 'secondary,' triggered by a prior head injury, brain infection, tumor, or bleeding in the brain (for example, after a fall). The condition was first described in the 1960s by neurosurgeon Salomón Hakim and neurologist Raymond Adams, who noticed that some patients with dementia, gait trouble, and incontinence improved when the excess fluid was drained — which is why the syndrome is sometimes called the 'Hakim triad.' NPH is not the same as Alzheimer's, though the two can occur together, especially in people over 80.

General caregiving information, not medical advice. Check medications and major care changes with your clinician.

Step-by-step

  1. Keep a dated symptom log of the 'classic trio' — walking changes (shuffling, stumbling, feet stuck, needing help to stand), thinking changes (forgetfulness, slowed responses, confusion), and bladder changes (urgency, frequency, accidents). Note when each started and whether walking trouble came before memory issues. Bring this to every appointment.

  2. Schedule a visit with the primary care doctor and state your concern plainly: 'I'm worried about normal-pressure hydrocephalus because [name] has trouble walking, memory lapses, and bladder accidents. Can we check for that?' Hand over your symptom log and any existing imaging reports.

  3. Request a referral to a neurologist, memory clinic, or geriatrician experienced with NPH. If the doctor hesitates, say: 'I know NPH is rare but potentially reversible — could we get a specialist opinion before assuming Alzheimer's?'

  4. Ask the clinician to rule out other reversible causes of dementia at the same time — vitamin B12 deficiency, thyroid problems, chronic subdural hematoma (often after a fall), and medication side effects (including over-the-counter anticholinergics).

  5. Get brain imaging — an MRI is preferred over CT — to look for enlarged ventricles that are out of proportion to any brain shrinkage. No special preparation is needed; if your loved one is anxious, ask the imaging center about a mild sedative or calming music.

  6. If the scan suggests NPH, discuss a lumbar puncture (CSF tap test) with the neurologist to drain a small amount of fluid and see if symptoms temporarily improve. Ask about the opening pressure and how to prepare (see the Tap Test Preparation Checklist).

  7. After the tap test, watch closely for 24–48 hours for any improvement in walking or thinking and write down specific examples (e.g., 'Walked to the bathroom without shuffling for the first time in weeks').

  8. If the tap test shows improvement, consult a neurosurgeon about a shunt — a tube that drains excess fluid into the abdomen. Ask about surgical risks, recovery time, and what percentage of patients improve.

  9. If the tap test is negative, ask about a longer CSF drainage trial (a lumbar drain over several days) or whether a cisternogram (a scan that tracks how CSF flows) could add information before NPH is ruled out.

  10. Plan ahead for the likelihood of mixed dementia, and after any shunt surgery monitor for complications (headache, confusion, fever, return of symptoms) and attend all follow-up visits.

What not to do

  • Don't dismiss the symptoms as 'just normal aging' — NPH is treatable and worth investigating.

  • Don't wait for all three classic symptoms to appear. Even one — especially a new shuffling or unsteady gait — warrants evaluation.

  • Don't accept an 'it's just dementia' label without further testing. Ask directly: 'I'd like to rule out a reversible cause.'

  • Don't skip the lumbar puncture out of fear — it is generally safe and gives critical information. Ask for a clear risk/benefit explanation.

  • Don't rush into shunt surgery without a confirmatory CSF tap test; surgery carries real risk and can sometimes worsen cognition in someone who also has Alzheimer's.

  • Don't expect a complete cure. NPH often coexists with other dementias, and shunts tend to improve walking and bladder control more reliably than memory. Set realistic expectations.

  • Don't overlook the other reversible causes of dementia (B12 deficiency, thyroid disease, subdural hematoma, medication effects) — confirm they've been checked.

Practical tools

  • Symptom Tracking Log

    Keep a dated log with columns: Date, Symptom (gait / thinking / bladder), and Description. Examples: 'gait: shuffling, needed help standing'; 'thinking: forgot appointment'; 'bladder: urgency, accident once daily'; or a win like 'walked 20 steps without holding the wall.' Use a notebook or a free app and bring it to every appointment to show patterns and onset.

  • Doctor Conversation Scripts

    For scheduling: 'My [mother/father] has trouble walking — shuffling, unsteady — plus memory and bladder issues. I'm concerned about NPH. Can we discuss this?' For pushback: 'I know NPH is rare but reversible. I'd like to rule it out before assuming Alzheimer's. Can we do imaging and a spinal tap?' For facilities: 'This could be a reversible condition, and treating it might reduce falls and incontinence and lower care costs.'

  • Questions for the Neurologist / Neurosurgeon

    Print and bring: (1) Do the scans show enlarged ventricles, and is it NPH or atrophy from Alzheimer's? (2) What is the opening pressure on the spinal tap — is it in the normal range? (3) Will a tap test help decide about a shunt? (4) If the tap test is negative, can we do a longer drainage trial or a cisternogram? (5) What are the specific risks of shunt surgery (infection, bleeding, stroke) for my loved one's age and health, and what is your success rate? (6) How long does improvement from the tap last? (7) How will we know if the shunt is helping if Alzheimer's is also present?

  • CSF Tap Test Preparation Checklist

    Before the lumbar puncture: (1) Ask whether to stop blood thinners (e.g., aspirin) a few days beforehand — confirm timing with the prescribing doctor; never stop medication on your own. (2) Arrange a driver to and from the appointment. (3) Plan for your loved one to lie flat for about an hour afterward to help prevent a post-puncture headache.

  • Post-Tap Observation Checklist

    Monitor for 24–48 hours after the tap test and record specifics: (1) Walking — steadier? less shuffling? (2) Thinking — faster responses? better recall? (3) Bladder — fewer accidents or less urgency? (4) Mood/alertness — more engaged? Write concrete examples (e.g., 'walked without holding the wall') to help the team decide whether a shunt is worthwhile.

  • Rule-Out List for Other Reversible Dementias

    Ask the clinician to check and document: vitamin B12 level, thyroid function (TSH), brain imaging for a chronic subdural hematoma (especially after any fall), and a full review of all medications including over-the-counter anticholinergics (e.g., diphenhydramine in many sleep aids and allergy meds). These conditions can mimic or worsen dementia and may be treatable.

The walking change is usually the earliest and clearest sign — if a once-steady person starts shuffling or feels their feet are 'stuck,' flag it right away.

Bring your symptom log to every visit; concrete dated examples are far more persuasive than 'he's been off lately.'

Use the phrase 'potentially reversible' when asking for testing — it signals you understand why ruling out NPH matters.

Before the tap test, double-check three things: blood thinner timing (with the prescriber), a confirmed driver, and a plan to lie flat afterward.

Capture a short 'before' video of your loved one walking, so you and the team can compare gait honestly after the tap test.

Improving gait even a little can cut fall risk and incontinence, which improves quality of life — that benefit can be worth pursuing even when memory won't fully recover.

Discuss with your clinician

Ask: 'Could my loved one's symptoms be normal-pressure hydrocephalus, and what tests would you recommend?' If a scan shows enlarged ventricles, ask whether it's NPH or atrophy from Alzheimer's and how they can tell. About the tap test, ask for the exact opening pressure and whether it's in the normal range, whether the test is safe at my loved one's age, and how long any improvement lasts. If a shunt is recommended, ask about the specific risks of infection, bleeding, or stroke and the surgeon's success rate and expected recovery and follow-up care. Ask whether a longer CSF drainage trial or a cisternogram is an option if the tap test is negative. Ask whether a medication review (including over-the-counter anticholinergics like diphenhydramine) should be done and whether other reversible causes — B12 deficiency, thyroid disease, subdural hematoma — have been ruled out. Finally, if mixed dementia is likely, ask how you'll know whether the shunt is helping and what treatments (such as donepezil or memantine) might help Alzheimer's symptoms. Always confirm any medication question with the prescribing clinician before making changes.

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