How should I evaluate and manage a 66-year-old man presenting with positional dizziness, vomiting, horizontal nystagmus, normal neurological exam and normal vital signs?

Approach to This Patient

This patient most likely has benign paroxysmal positional vertigo (BPPV), but you must immediately perform a Dix-Hallpike maneuver and supine roll test to confirm the diagnosis and rule out central causes of positional vertigo that can masquerade as BPPV.

Immediate Diagnostic Steps

1. Perform Positional Testing NOW

The presence of horizontal nystagmus alone is insufficient for diagnosis. You need to:

• Dix-Hallpike maneuver: This tests for posterior canal BPPV (85-95% of BPPV cases) 1. Look for upbeating-torsional nystagmus with latency and fatigability.

• Supine roll test: This tests for lateral/horizontal canal BPPV (5-15% of cases) 1. The patient already has horizontal nystagmus, making this particularly important.

  • Geotropic nystagmus (beats toward the ground): suggests canalolithiasis
  • Apogeotropic nystagmus (beats away from ground): suggests cupulolithiasis 2, 3

2. Critical Red Flags to Assess

You must actively exclude central causes, as 10% of cerebellar strokes present similarly to peripheral vestibular processes 1. The following features suggest a central rather than peripheral cause:

• Direction-changing nystagmus WITHOUT head position changes (periodic alternating nystagmus) 1
• Downbeating nystagmus on Dix-Hallpike WITHOUT torsional component 1
• Gaze-evoked nystagmus (beats right with right gaze, left with left gaze) 1
• Baseline nystagmus present without provocative maneuvers 1
• Any neurologic signs: dysarthria, dysmetria, dysphagia, sensory/motor deficits, Horner's syndrome 1

Important caveat: The patient's normal finger-to-nose test and normal alternating hand movements are reassuring but NOT sufficient to exclude central pathology. Cerebellar strokes can present with isolated positional vertigo 1, 4.

Clinical Reasoning for This Case

Why BPPV is Most Likely:

• Positional trigger (lying to sitting)
• Acute onset (1 day)
• Multiple vomiting episodes (common with BPPV)
• Normal vital signs
• Normal neurological examination
• Age 66 (BPPV prevalence increases with age)

Why You Cannot Stop Here:

• Horizontal nystagmus was noted but the TYPE matters critically 2, 3:

  • Is it geotropic or apogeotropic?
  • Does it change direction with head position changes?
  • Is there latency and fatigability?

• The examination is incomplete without positional maneuvers 1, 5

• 3% of presumed BPPV treatment failures are actually CNS disorders 1

Management Algorithm

If Dix-Hallpike or Supine Roll Test is POSITIVE for BPPV:

1. Posterior canal BPPV (upbeating-torsional nystagmus on Dix-Hallpike):

   • Perform Epley maneuver immediately 1
   • 75% cure rate at 1 week 2

2. Horizontal canal BPPV (horizontal nystagmus on supine roll test):

   • Geotropic variant: Perform barbecue roll maneuver (360° rotation toward healthy ear) 2, 3
   • Apogeotropic variant: Consider VAV modification of Semont's maneuver 3
   • 86-100% cure rates with up to 4 treatments 1

3. Symptomatic management:

   • Antiemetics for vomiting (ondansetron, metoclopramide)
   • Avoid vestibular suppressants (meclizine, benzodiazepines) as they delay central compensation 1

If Positional Testing Shows RED FLAGS:

Obtain urgent brain MRI if you observe:

• Pure downbeating nystagmus without torsional component 1, 6
• Direction-changing nystagmus without position changes 1
• Gaze-evoked nystagmus 1
• Any new neurologic findings

Recent case reports document cerebellar hemangioblastomas and other posterior fossa lesions presenting identically to BPPV 4.

Critical Fall Risk Assessment

This 66-year-old patient is at HIGH RISK for falls 1:

• 12-fold increased fall risk with symptomatic dizziness
• 1 in 3 adults >65 years fall annually
• BPPV accounts for 13% of falls in elderly 1

Immediate safety measures:

• Assess home support and mobility
• Educate about fall prevention
• Consider physical therapy referral if balance impairment persists 1

Follow-up Plan

• Reassess in 1 week if symptoms persist after canalith repositioning 1

• Consider alternative diagnoses if no response to treatment:

  • Vestibular migraine (requires ≥5 episodes lasting 5 min-72 hours with migraine features) 1
  • Vestibular neuritis (would have baseline nystagmus, not purely positional) 5
  • Central pathology 1

• Watch for canal conversion: 6% of cases convert from one canal to another after treatment 1

The key pitfall is assuming this is BPPV without performing the diagnostic maneuvers—horizontal nystagmus alone does not confirm the diagnosis and could represent a central lesion 1, 7.