What is the typical management of Normal Pressure Hydrocephalus (NPH)?

Management of Normal Pressure Hydrocephalus (NPH)

The definitive treatment for Normal Pressure Hydrocephalus is cerebrospinal fluid (CSF) diversion via ventriculoperitoneal (VP) shunt placement, which has been shown to improve symptoms in approximately 90% of appropriately selected patients. 1, 2

Diagnosis and Patient Selection

• NPH presents with the classic triad of gait disturbance, urinary incontinence, and cognitive decline (dementia) 3
• Diagnosis should be confirmed with contrast-enhanced MRI showing ventriculomegaly without cerebral atrophy, and possible transependymal edema 4, 1
• Patient selection for shunt placement should involve a standardized assessment protocol to identify those most likely to benefit from surgical intervention 2

Diagnostic Testing to Predict Shunt Response

• A CSF tap test (large-volume lumbar puncture) with pre- and post-procedure assessment of gait and cognitive function is recommended to predict shunt response 5
• Improvement in 2 or more tests after CSF removal strongly predicts a positive outcome following shunt placement 5
• Specific validated tests include:
  • Gait and balance assessments: Timed "Up & Go", Tinetti Gait and Balance Assessment, Berg Balance Scale 2
  • Cognitive assessments: Mini Mental Status Exam, Trail Making Test Part B 2

Treatment Options

Primary Treatment: CSF Shunting

• Ventriculoperitoneal (VP) shunt is the standard surgical treatment for NPH 1, 3
• Approximately 70-90% of properly selected patients show clinical improvement following shunt placement 3
• Improvement is typically seen in gait first, followed by urinary symptoms and cognitive function 3

Alternative Treatment: Endoscopic Third Ventriculostomy (ETV)

• ETV may be considered as an alternative to VP shunt in selected patients 1
• ETV has higher early failure rates than shunts but lower failure rates after 3 months 1
• Both CSF shunts and ETV demonstrate equivalent overall outcomes in many clinical scenarios 1

Monitoring and Follow-up

• Regular follow-up is essential as approximately 45% of patients may experience symptom recurrence by one year after shunt placement 2
• Any changes in mental status, gait disturbance, or urinary symptoms should prompt evaluation for shunt malfunction 4

Complications

• Potential complications of shunt placement include:
  • Subdural fluid collections (18% of cases) 2
  • Other serious complications including seizures, intracerebral hemorrhage, and stroke (6% of cases) 2
  • Shunt infection or malfunction 3

Important Considerations

• Early diagnosis and treatment lead to better outcomes, as untreated NPH typically progresses to nursing home dependence 3
• Approximately 75% of NPH patients may have comorbid neurodegenerative disorders, complicating diagnosis and treatment decisions 3
• Routine use of serial lumbar punctures is not recommended as a definitive treatment 1
• Despite the lack of randomized controlled trials comparing shunting to no treatment 6, current evidence supports shunt placement as the standard of care for appropriately selected patients 3