What is the appropriate diagnosis and treatment for an elderly patient with a rapid decline in function and cognition, severe headaches, and dizziness, suspected of having Normal Pressure Hydrocephalus (NPH)?

Approach to Suspected NPH with Rapid Decline and Severe Headaches

This patient's rapid 1.5-month decline with severe headaches and dizziness is atypical for classic NPH and demands urgent neuroimaging to exclude life-threatening alternative diagnoses before proceeding with standard NPH evaluation.

Critical Red Flags Requiring Immediate Investigation

The presentation described is highly concerning for conditions other than typical NPH, which usually progresses slowly over months to years. The severe headaches combined with rapid functional decline warrant urgent exclusion of:

• Subdural hematoma (elderly patients are at risk for intracranial bleeding) 1
• Cerebral venous thrombosis (can present with headache, cognitive decline, and may be associated with intracranial hypotension) 1
• Obstructive hydrocephalus from mass lesion or aqueductal stenosis (would cause elevated intracranial pressure, not "normal pressure")
• Spontaneous intracranial hypotension (severe headaches with dizziness are characteristic) 1

Initial Imaging Approach

Obtain MRI head without IV contrast as the first-line imaging study 1, 2, 3. This is superior to CT for evaluating NPH and can simultaneously identify alternative diagnoses.

Key MRI Sequences and Findings to Assess:

• 3D T1 volumetric sequence with coronal reformations 1
• FLAIR sequence to evaluate periventricular white matter changes 1
• T2 or susceptibility-weighted imaging (SWI) to detect hemorrhage or venous abnormalities 1
• Diffusion-weighted imaging (DWI) 1

If MRI is Contraindicated:

Perform non-contrast CT head with coronal reformations 1. While less sensitive than MRI, CT can identify ventriculomegaly and exclude acute hemorrhage or mass lesions 1.

History: Specific Elements to Elicit

NPH-Specific Features:

• Gait disturbance characteristics: Ask about feet feeling "glued to the floor" or "magnetic" appearance when walking—this is the cardinal and often earliest sign of NPH, occurring in ~70% of patients 3, 4
• Urinary symptoms: Urgency, frequency, nocturia, and incontinence (not just general incontinence) 4
• Cognitive pattern: Frontal/subcortical symptoms including psychomotor slowing, attention deficits, working memory problems, verbal fluency issues, and executive dysfunction 2, 5

Red Flag History:

• Recent head trauma (even minor in elderly on anticoagulation) 1
• Cancer history (risk for brain metastases) 1
• Anticoagulation or bleeding risk factors 1
• Headache characteristics: Severe, new-onset headaches are not typical of NPH and suggest alternative pathology 1

Physical Examination: Focused Findings

Neurological Examination:

• Gait assessment: Look for hypokinetic, broad-based gait with short shuffling steps, reduced foot clearance, and difficulty with turns 3, 4
• Postural stability and balance testing 4
• Babinski sign (if present, suggests alternative pathology requiring urgent imaging) 1
• Focal neurological deficits (would be atypical for NPH alone)

Cognitive Assessment:

Use validated, simple tools:

• Montreal Cognitive Assessment (MoCA) or Mini-Mental State Examination (MMSE) for baseline cognitive screening 1
• Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) to assess rate of decline 1

Investigations Beyond Imaging

If MRI Confirms NPH Pattern:

Classic imaging findings of NPH include 1, 2, 3:

• Ventriculomegaly (not entirely attributable to atrophy)
• Narrowed posterior callosal angle (<90°)
• Effaced sulci along high convexities with widened sylvian fissures
• Periventricular white matter changes
• Cerebral aqueduct flow void (critical finding on MRI that CT cannot detect) 1, 3

Predictive Testing for Shunt Responsiveness:

Large-volume lumbar puncture (removing 40-50 mL CSF) or prolonged external lumbar drainage is the most reliable predictor of shunt response 3, 5. Document gait and cognitive function before and 18-24 hours after the procedure 4.

• Transient improvement following CSF removal strongly predicts surgical benefit 3, 4
• Properly selected patients have an 80-90% chance of responding to shunt surgery 3

Additional Testing:

• Phase-contrast MRI to measure aqueductal CSF stroke volume (elevated values have high positive predictive value for shunt responsiveness) 3
• Lumbar puncture opening pressure should be normal (<250 mm H₂O) by definition 3

Treatment Algorithm

If Alternative Diagnosis Identified:

Treat accordingly (e.g., subdural hematoma evacuation, anticoagulation for venous thrombosis, epidural blood patch for intracranial hypotension).

If NPH Confirmed and Predictive Testing Positive:

Ventriculoperitoneal shunt placement is the definitive treatment 3, 4, 6:

• All three symptoms (gait, cognition, urinary) can potentially improve 3
• Serious complication rate is approximately 6% 3
• Gait improvement typically occurs first, followed by cognitive and urinary symptoms 4, 6

Important Caveat:

20-57% of NPH patients have comorbid Alzheimer's disease 2. Cognitive improvement may be partial if neurodegenerative disease coexists. However, shunting can still provide meaningful functional benefit even with comorbidities 2.

Critical Clinical Pitfall

The rapid 1.5-month timeline with severe headaches is NOT consistent with typical idiopathic NPH, which develops insidiously over months to years 2, 5. This presentation pattern mandates aggressive investigation for:

• Secondary causes of hydrocephalus (tumor, hemorrhage, infection)
• Intracranial hypotension with rebound venous congestion 1
• Acute-on-chronic subdural collections

Do not proceed directly to NPH workup without first excluding these urgent, life-threatening conditions through comprehensive neuroimaging 1.