What is the recommended treatment for an adult with suspected normal‑pressure hydrocephalus presenting with gait disturbance, cognitive decline, and urinary incontinence?

Treatment of Normal Pressure Hydrocephalus

For an adult with suspected normal pressure hydrocephalus presenting with the classic triad, the definitive treatment is CSF shunting (ventriculoperitoneal shunt), which provides significant symptom improvement in appropriately evaluated patients and should be pursued after diagnostic confirmation with brain MRI showing characteristic features and consideration of supplemental prognostic testing.

Diagnostic Confirmation First

Before proceeding to treatment, confirm the diagnosis with:

• Brain MRI with contrast showing ventriculomegaly, high-convexity tight sulci, enlarged sylvian fissures, and periventricular white matter changes 1
• Look specifically for disproportionately enlarged subarachnoid-space hydrocephalus (DESH), which is essential for diagnosis 2
• Supplemental prognostic tests to predict shunt responsiveness: CSF tap test (removal of 30-50 mL CSF with clinical reassessment) or external lumbar drainage 3, 2

Definitive Treatment: CSF Shunting

Ventriculoperitoneal (VP) shunt placement is the gold standard treatment for iNPH 4, 5. The evidence strongly supports this approach:

• Significant improvement occurs in all three components of the triad: gait disturbance, cognitive decline, and urinary incontinence 4, 5
• Benefits persist long-term, with sustained improvement documented up to 6 years post-operatively 5
• In one cohort, urinary incontinence improved from 70.4% to 29.6% of patients, and 32% showed significant cognitive improvement on Montreal Cognitive Assessment 5
• Gait improves measurably, with the number of steps needed for 180° turn decreasing from 4.4 to 2.8 steps 5

Treatment Algorithm

1. Confirm clinical triad: Gait disturbance (typically the earliest symptom), cognitive decline, and urinary incontinence 2, 6

2. Obtain brain MRI with contrast to identify characteristic features 1, 2

3. Perform supplemental testing (CSF tap test or external lumbar drainage) to predict shunt responsiveness 3, 2

4. Proceed to VP shunt placement if imaging and clinical response to CSF removal are positive 4, 2, 5

5. Early neurosurgical consultation is critical—do not delay referral 2

Alternative Consideration: Endoscopic Third Ventriculostomy

ETV is NOT recommended as first-line treatment for iNPH. While ETV is an option in pediatric hydrocephalus 7, the evidence for iNPH specifically shows:

• One study attempted ETV in iNPH, but the patient required subsequent VP shunt placement due to clinical deterioration 4
• The authors concluded that "a properly designed study is required to address the efficacy of ETV in the treatment of iNPH" 4
• VP shunt remains the proven, evidence-based treatment for this population

Critical Pitfalls to Avoid

Do not mistake iNPH for stroke or neurodegenerative disease. Atypical presentations can include focal deficits, hemiplegia, or aphasia that mimic cerebrovascular events 6. The key distinguishing features are:

• Progressive ventriculomegaly on serial imaging
• Clinical improvement with CSF removal (tap test)
• Absence of other explanatory pathology

Do not delay treatment. Early intervention prevents unnecessary morbidity and can result in complete symptom resolution within 6 weeks of shunt placement 6. Delayed diagnosis leads to progressive, potentially irreversible decline.

Recognize that normal CSF pressure does not exclude the diagnosis—the term "normal pressure" is inherent to the condition 3, 2.

Expected Outcomes

With appropriate patient selection using supplemental prognostic testing, the majority of patients experience significant symptom improvement 3. The NPH-Recovery Rate remains favorable for at least 3 years post-shunting, representing good clinical outcome 5. Patients can return to normal functional status, with some achieving complete resolution of all symptoms 6.