What is the treatment for Normal Pressure Hydrocephalus (NPH)?

Treatment of Normal Pressure Hydrocephalus (NPH)

The definitive treatment for Normal Pressure Hydrocephalus (NPH) is surgical intervention with ventriculoperitoneal (VP) shunt placement, which leads to clinical improvement in 70-90% of properly selected patients. 1

Diagnosis and Patient Selection

• NPH is characterized by the clinical triad of gait disturbance, urinary incontinence, and cognitive impairment, along with ventriculomegaly on imaging 1
• Diagnosis should be confirmed with MRI with contrast to evaluate for ventriculomegaly and to rule out other causes 2
• Temporary CSF diversion via lumbar drain trial is recommended to identify patients likely to benefit from permanent shunting 3
• Standardized assessment of gait, balance, and cognition before and after temporary CSF diversion helps identify appropriate surgical candidates 3

Surgical Management Options

Ventriculoperitoneal (VP) Shunt

• VP shunt is the most established and effective treatment for NPH 4
• Clinical improvement is most prominent within the first 6 months after shunting and can be maintained long-term 4
• Programmable valves allow for pressure adjustments based on clinical response, with median opening pressures of 120 mmH2O for women and 140 mmH2O for men 4
• Modern surgical techniques using stereotactic navigation and laparoscopic assistance for distal catheter placement have reduced complication rates 5

Endoscopic Third Ventriculostomy (ETV)

• ETV has emerged as an alternative to VP shunts for treating hydrocephalus in selected patients 2
• When adjusted for patient age and etiology, ETV has higher early failure rates than shunts but lower failure rates after 3 months 6
• Both CSF shunts and ETV demonstrate equivalent overall outcomes in many clinical scenarios (Level II evidence) 6

Prognostic Factors

• Shorter duration of gait disturbance predicts better improvement in gait after shunting 7
• Use of cognition-enhancing medication is associated with greater improvement in cognition and/or incontinence after shunting 7
• Comorbidities like diabetes mellitus and history of stroke can influence surgical outcomes 4
• Approximately 45% of patients may experience symptom recurrence by 1-year follow-up despite initial improvement 3

Complications and Management

• Common complications of VP shunts include:

  • Misplaced proximal catheters (5.1%) 7
  • Subdural fluid collections/hematomas (4.3%) 7
  • Bilateral hygromas (6%) 7
  • CSF leaks (0.9%) 7
  • Shunt infection (rare with modern techniques) 5

• Patients with cardiac or neurological comorbidities have higher rates of readmission and complications 5

• Regular follow-up with neuroimaging and clinical assessment is essential to monitor for complications 3

Treatment Algorithm

1. Confirm diagnosis with clinical evaluation and neuroimaging 1
2. Perform temporary CSF diversion test (lumbar drain trial) 3
3. If positive response to CSF diversion:
   • For most patients, proceed with VP shunt placement with programmable valve 4
   • Consider ETV in selected patients with suitable anatomy 2
4. Post-surgical management:
   • Regular follow-up at 2 weeks, 6 weeks, and then periodically 7
   • Valve pressure adjustments based on clinical response 4
   • Monitor for complications with neuroimaging as needed 3

Pitfalls and Caveats

• NPH is often underdiagnosed, with approximately 80% of cases remaining unrecognized and untreated 1
• Three-quarters of NPH patients may also have another neurodegenerative disorder, complicating diagnosis and treatment response 1
• Routine use of serial lumbar punctures is not recommended as a definitive treatment (Level I evidence) 6
• The differential diagnosis of NPH can be challenging, requiring careful evaluation to distinguish from other neurodegenerative conditions 1