In a 79‑year‑old woman who experiences brief vertigo episodes triggered by turning her head that stop when she closes her eyes, should I order a CT scan to evaluate for normal‑pressure hydrocephalus?

No CT Scan Needed – This is Classic BPPV, Not NPH

You should NOT order a CT scan. This patient's presentation is textbook benign paroxysmal positional vertigo (BPPV), and imaging is not indicated for typical BPPV 1. The concern about normal pressure hydrocephalus (NPH) is misplaced here.

Why This is BPPV, Not NPH

Your patient describes the hallmark features of BPPV:

• Brief episodes of vertigo (not persistent)
• Triggered specifically by head turning (positional)
• Spinning sensation that resolves when eyes are closed
• Episodic nature (occasional, not constant)

This is Variant 1 from the ACR guidelines: brief episodic vertigo triggered by specific head movements 1.

Why This is NOT NPH

NPH presents with a completely different clinical picture 2, 3, 4:

• Gait disturbance (the first and most prominent symptom – gait apraxia, magnetic gait)
• Cognitive impairment/dementia (progressive mental deterioration)
• Urinary incontinence (develops later)
• Persistent, chronic symptoms (not brief episodic vertigo)
• Ventriculomegaly on imaging with normal CSF pressure

Your patient has none of the NPH triad. Vertigo is not a primary feature of NPH 3, 4.

What You Should Do Instead

1. Perform a Dix-Hallpike maneuver in your office to confirm BPPV

   • Look for characteristic rotatory nystagmus
   • The test itself is diagnostic

2. If Dix-Hallpike is positive (typical nystagmus):

   • Perform Epley maneuver for treatment
   • No imaging needed 1
   • This has ~80% success rate

3. Only consider imaging if atypical features 1:

   • Lack of nystagmus on Dix-Hallpike despite symptoms
   • No response to Epley maneuver after multiple attempts
   • Associated neurological deficits
   • Persistent (not episodic) vertigo

If You Must Image (Atypical Cases Only)

MRI brain without contrast is preferred over CT if imaging becomes necessary 1. CT has very low yield (<1%) in isolated vertigo with normal neurological exam 1. However, for typical BPPV with positive Dix-Hallpike, even MRI is unnecessary 1.

Common Pitfall to Avoid

Don't conflate age-related concerns with actual clinical presentation. While NPH does affect elderly patients, the diagnosis requires the classic triad plus imaging findings of ventriculomegaly 2, 3. Brief positional vertigo in a 79-year-old is still BPPV until proven otherwise.

Bottom line: Perform Dix-Hallpike testing, treat with Epley maneuver if positive, and skip the CT scan entirely unless atypical features emerge.