What is the treatment for Normal pressure hydrocephalus (NPH)?

Treatment of Normal Pressure Hydrocephalus (NPH)

Ventriculoperitoneal (VP) shunt placement is the definitive treatment for NPH and leads to clinical improvement in 70-90% of patients, with sustained benefit for 5-7 years or longer. 1, 2

Definitive Surgical Management

VP shunt implantation is the treatment of choice for confirmed NPH, as it normalizes CSF dynamics and addresses the underlying pathophysiology of impaired CSF absorption. 3, 1

• Shunt surgery improves gait disturbance in 83-87% of patients at long-term follow-up (3-7 years), making mobility improvement the most reliable outcome. 2
• Cognitive symptoms show intermediate improvement (84-86% sustained improvement), while urinary incontinence demonstrates the least but still substantial improvement (80% at 7 years). 2
• Early diagnosis and treatment significantly increases success rates, as the spontaneous course of untreated NPH leads to nursing care dependence in the vast majority of patients. 1, 4

Pre-Surgical Diagnostic Confirmation

Before proceeding to shunt surgery, semi-invasive diagnostic procedures are recommended when clinical findings and imaging alone are insufficient to establish surgical indication. 1

• Lumbar puncture with large-volume CSF removal (30-50 mL) serves as both diagnostic and therapeutic test, with clinical improvement in gait or cognition within hours to days predicting positive shunt response. 3, 1
• Opening pressure measurements during lumbar puncture may be normal or only mildly elevated in NPH, which is characteristic of this condition. 3, 5
• Contrast-enhanced MRI is essential to evaluate ventriculomegaly, periventricular lucencies (transependymal edema), and to distinguish NPH from other neurodegenerative disorders. 3

Critical Diagnostic Considerations

Three-quarters of patients with NPH severe enough to require treatment have coexisting neurodegenerative disorders, making differential diagnosis challenging. 1

• The classic triad of gait impairment, urinary incontinence, and dementia must be present, with gait disturbance typically appearing first and being most responsive to treatment. 1, 6, 4
• Approximately 80% of NPH cases remain unrecognized and untreated due to difficulty distinguishing it from other dementias, making it a critical diagnosis not to miss. 1, 4
• NPH accounts for approximately 5% of dementia cases and represents one of the few reversible causes of dementia. 4

Long-Term Management and Monitoring

Fifty-three percent of patients require shunt revisions during long-term follow-up, making ongoing surveillance essential. 2

• Indications for revision include shunt malfunction (87% of revisions), infection (10%), and configuration changes (3%). 2
• Seventy-four percent of revision surgeries result in clinical improvement, supporting aggressive management of shunt complications. 2
• Serial neurological examinations and repeat neuroimaging should be obtained if clinical status changes or deteriorates. 7

Special Circumstances: Acute Presentation

If NPH presents with acute decompensation or increased intracranial pressure (rare but possible):

• Urgent neurosurgical consultation for external ventricular drain (EVD) placement is indicated for acute symptomatic hydrocephalus with altered consciousness. 7
• Medical management with repeated lumbar punctures can stabilize pressure temporarily, removing CSF to reduce pressure to 50% of opening pressure or 200 mm H₂O, whichever is greater. 3, 7
• Endoscopic third ventriculostomy (ETV) may be considered in select cases with evidence of obstruction, though VP shunt remains first-line for communicating NPH. 3

Common Pitfalls to Avoid

• Do not delay treatment once diagnosis is confirmed, as early intervention significantly improves outcomes and prevents progression to nursing care dependence. 1, 4
• Do not dismiss NPH in patients with coexisting dementia, as treatment can still provide meaningful improvement in mobility and quality of life. 1
• Do not assume normal intracranial pressure excludes the need for treatment—the "normal pressure" in NPH is part of the disease definition, not a contraindication to shunting. 5, 6