What is the management of Normal Pressure Hydrocephalus (NPH) in the Emergency Department (ED)?

Management of Normal Pressure Hydrocephalus in the Emergency Department

In patients with suspected Normal Pressure Hydrocephalus (NPH) presenting to the Emergency Department, urgent cerebrospinal fluid (CSF) diversion via external ventricular drainage (EVD) or lumbar drainage should be performed if the patient demonstrates acute symptomatic hydrocephalus to improve neurological outcomes.

Initial Assessment and Diagnosis

Clinical Presentation

• Look for the classic triad of NPH symptoms:
  • Gait disturbance (typically shuffling, bradykinetic, with decreased step height)
  • Cognitive impairment (frontal-subcortical pattern)
  • Urinary incontinence (or fecal incontinence in advanced cases)
• Additional symptoms that may be present:
  • Recurrent falls
  • Unsteady balance
  • Memory problems
  • Altered mental status

Diagnostic Imaging

• Urgent neuroimaging with CT or MRI is essential to distinguish NPH from other neurological conditions 1
• Key radiographic findings:
  • Ventriculomegaly (disproportionate dilation of lateral and third ventricles)
  • Transependymal edema in acute cases
  • Brain tissue volume loss
  • Absence of significant cortical atrophy relative to ventricular enlargement

Emergency Management Algorithm

Step 1: Stabilization and Initial Management

• Assess and stabilize airway, breathing, and circulation
• Perform focused neurological examination, including gait assessment if patient is ambulatory
• Document baseline neurological status using a standardized severity score 1

Step 2: Determine Acuity and Need for Urgent Intervention

• For acute symptomatic hydrocephalus:
  • Urgent CSF diversion via EVD or lumbar drainage is recommended 1
  • This should be done in consultation with neurosurgery
• For chronic/stable NPH symptoms:
  • Arrange for admission and further diagnostic testing
  • Consider large-volume lumbar puncture (tap test) if patient is stable

Step 3: Neurosurgical Consultation

• Early neurosurgical consultation is essential for:
  • Patients with acute symptomatic hydrocephalus
  • Determining the need for permanent CSF diversion
  • Planning for potential shunt placement

Special Considerations

Implementation of EVD

• If EVD is placed, implement and adhere to an EVD bundled protocol to reduce complications and infection rates 1
• Key components of EVD management include:
  • Proper insertion technique with aseptic precautions
  • Standardized dressing care
  • Monitoring for signs of infection
  • Careful CSF sampling technique when needed

Transfer Considerations

• For facilities without neurosurgical capabilities, arrange urgent transfer to a center with:
  • Neurosurgical expertise
  • Neurointensive care capabilities
  • Experience in managing NPH 1
• Do not delay transfer for patients requiring urgent intervention, though initiating treatment before transfer is recommended when possible 1

Diagnostic Testing in Stable Patients

For stable patients with suspected NPH who do not require emergency intervention:

• Tap test (large-volume lumbar puncture):
  • Remove 30-50 mL of CSF
  • Measure opening pressure (typically normal or slightly elevated)
  • Assess for improvement in gait and cognition after CSF removal 2
  • This can be both diagnostic and predictive of shunt response

Disposition

• Admission criteria:

  • All patients with acute symptomatic hydrocephalus
  • Patients with new or worsening NPH symptoms
  • Patients requiring further diagnostic evaluation

• Discharge considerations:

  • Stable, chronic NPH patients with mild symptoms may be discharged with close neurosurgical follow-up
  • Ensure adequate home support and fall precautions

Pitfalls and Caveats

• NPH can mimic or coexist with other neurodegenerative disorders, making diagnosis challenging 3
• Up to 80% of NPH cases remain unrecognized and untreated 3
• Normal CSF pressure does not exclude NPH diagnosis
• Patients with NPH may have comorbid conditions that complicate diagnosis and management
• The risk of neurological deterioration is highest within the first 12-48 hours after symptom onset 1

By following this structured approach to the management of NPH in the emergency department, clinicians can ensure appropriate and timely interventions to improve patient outcomes and reduce morbidity and mortality.