What are the symptoms of Normal Pressure Hydrocephalus (NPH)?

Normal Pressure Hydrocephalus Symptoms

Normal Pressure Hydrocephalus (NPH) is characterized by the classic triad of gait disturbance, urinary incontinence, and cognitive impairment, with gait disturbance typically being the cardinal and earliest symptom. 1, 2

Classic Triad of NPH Symptoms

1. Gait Disturbance

• Most prominent and usually first symptom to appear 3
• Characterized by:
  • Hypokinetic, magnetic, or "glued to the floor" appearance 3
  • Shuffling steps
  • Bradykinesia (slowness of movement)
  • Wide-based stance
  • Difficulty initiating walking
  • Instability and increased risk of falls 4
  • Described as "magnetic gait" where feet appear stuck to the floor 3

2. Urinary Symptoms

• Usually develops after gait problems
• Presents as:
  • Urinary urgency
  • Frequency
  • Nocturia
  • Eventual incontinence 3
  • May progress to fecal incontinence in advanced cases 4

3. Cognitive Impairment

• Typically appears later in disease progression 1
• Manifests as:
  • Mild dementia
  • Memory impairment
  • Slowed thinking
  • Decreased attention
  • Executive dysfunction
  • Apathy

Progression Pattern

The symptoms typically follow a specific progression pattern:

1. Gait disturbance appears first and is the most prominent symptom
2. Urinary symptoms develop next
3. Cognitive impairment appears later in the disease course 1, 2

Patients often present late in the course of the disease due to the slow and gradual nature of symptom onset 1.

Clinical Pearls and Pitfalls

• Key Diagnostic Pearl: The combination of the triad with ventriculomegaly on imaging and normal CSF pressure on lumbar puncture is diagnostic 2
• Common Pitfall: NPH is frequently misdiagnosed as other neurodegenerative disorders, with approximately 80% of cases remaining unrecognized and untreated 5, 2
• Important Distinction: Unlike other forms of dementia, NPH is potentially reversible with CSF diversion through shunting 2
• Risk Factors: Diabetes, hypertension, trauma, intracranial hemorrhage, meningitis, venous sinus thrombosis, and vasculitis 2, 3
• Epidemiology: Affects approximately 3.7% of patients over 65 years of age 1, 2

Diagnostic Considerations

When NPH is suspected based on clinical symptoms:

• MRI brain is the preferred imaging modality, showing:

  • Ventriculomegaly
  • Narrowed posterior callosal angle
  • Effaced sulci along high convexities with widened sylvian fissures
  • Periventricular white matter changes
  • Cerebral aqueduct flow void 2

• CT head without contrast is an alternative but less sensitive for detecting all features 1, 2

• Diagnostic confirmation often requires a large-volume CSF tap (lumbar puncture) showing normal opening pressure with temporary improvement in symptoms 4

NPH should always be considered in elderly patients presenting with unexplained gait disturbance, especially when accompanied by urinary symptoms and cognitive changes, as it represents one of the few potentially reversible causes of dementia 6.