What is the differential diagnosis and next steps for an elderly male with intermittent dizziness triggered by lights and sounds, with a negative brain Magnetic Resonance Imaging (MRI)?

Differential Diagnosis and Management Plan

Most Likely Diagnosis

Vestibular migraine is the primary diagnosis to consider in this elderly male with intermittent dizziness triggered by lights and sounds, given the characteristic sensory triggers (photophobia and phonophobia) that distinguish it from other vestibular disorders. 1, 2

Key Differential Diagnoses

Primary Considerations

• Vestibular Migraine: Episodes triggered by lights and sounds are pathognomonic features, with attacks lasting minutes to hours (or even >24 hours), and patients typically report motion intolerance and light sensitivity as triggers 1, 2

  • Hearing loss is typically mild, absent, or stable over time—not fluctuating like Ménière's disease 2
  • May occur without headache in elderly patients, presenting as isolated vestibular symptoms 2

• Ménière's Disease: Must be excluded by specifically asking about the classic triad: fluctuating hearing loss that worsens over time, tinnitus, and aural fullness occurring before, during, or after vertigo attacks 1, 2

  • Episodes last hours (not seconds or days) 1
  • The key distinguishing feature is fluctuating hearing loss, not stable hearing 2

• Vertebrobasilar Insufficiency (Central Cause): Critical to rule out given age and potential vascular risk factors, presenting with episodes lasting <30 minutes without hearing loss 1, 2

  • May precede stroke by weeks or months 2
  • Associated with severe postural instability and falls 2

Less Likely Given Clinical Presentation

• BPPV: Would present with brief episodes (<1 minute, typically seconds) triggered specifically by head position changes relative to gravity, not by lights/sounds 1, 2

• Vestibular Neuritis/Labyrinthitis: Present with acute continuous vertigo lasting days to weeks, not intermittent episodes 1, 3

• Anxiety/Panic Disorder: Can present with chronic dizziness but typically lacks specific sensory triggers like lights and sounds 1

Immediate Workup Plan

History - Specific Questions to Ask

• Timing of episodes: Duration (seconds suggest BPPV, minutes to hours suggest vestibular migraine or vertebrobasilar insufficiency, days suggest vestibular neuritis) 1, 2

• Migraine features: Current or past migraine history, family history of migraine, and whether photophobia, phonophobia, or visual aura occur during at least 50% of vertigo episodes 2

• Hearing symptoms: Specifically ask about fluctuating hearing loss, tinnitus, and aural fullness to distinguish Ménière's disease from vestibular migraine 1, 2

• Vascular risk factors: Hypertension, diabetes, smoking, prior stroke/TIA to assess vertebrobasilar insufficiency risk 1, 2

• Positional triggers: Ask if symptoms occur with specific head movements relative to gravity (suggests BPPV) versus sensory triggers 1, 2

• Falls and postural instability: Severe postural instability with falling suggests central pathology requiring urgent imaging 2

Physical Examination - Critical Components

• Dix-Hallpike maneuver: Perform to rule out BPPV 1, 2

  • Peripheral (BPPV): Torsional and upbeating nystagmus with latency, fatigability, crescendo-decrescendo pattern 2
  • Central causes: Immediate onset, persistent, purely vertical without torsional component 2

• Nystagmus assessment without provocation: Baseline nystagmus without provocative maneuvers is a red flag for central pathology 2

  • Central: Pure vertical (upbeating or downbeating) without torsional component, direction-changing, not suppressed by visual fixation 2
  • Peripheral: Horizontal with rotatory component, unidirectional, suppressed by visual fixation 2

• Neurological examination: Assess for dysarthria, dysmetria, dysphagia, sensory/motor deficits, diplopia, limb weakness, truncal/gait ataxia 2

• Orthostatic vital signs: Rule out postural hypotension 1

• Gait and balance testing: Severe postural instability warrants immediate neuroimaging 2

Audiologic Testing

Comprehensive audiologic examination is mandatory to distinguish between vestibular migraine (stable/absent hearing loss) and Ménière's disease (fluctuating sensorineural hearing loss). 2, 3

Neuroimaging Indications

Do NOT routinely order MRI if the presentation is consistent with vestibular migraine or BPPV without red flags. 2

Red Flags Requiring Urgent MRI 2:

• Severe postural instability with falling
• New-onset severe headache with vertigo
• Any additional neurological symptoms (dysarthria, diplopia, weakness)
• Downbeating nystagmus on Dix-Hallpike without torsional component
• Direction-changing nystagmus or purely vertical nystagmus
• Failure to respond to appropriate peripheral vertigo treatments
• High vascular risk factors with concerning presentation

Treatment Approach Based on Diagnosis

If Vestibular Migraine Confirmed

• Lifestyle modifications: Identify and avoid triggers (lights, sounds, certain foods, stress) 2
• Prophylactic medications: Consider migraine prophylaxis (beta-blockers, calcium channel blockers, tricyclic antidepressants) 2
• Vestibular rehabilitation: Helpful for chronic symptoms 1, 4

If Ménière's Disease Confirmed

• Dietary sodium restriction (<1500-2000 mg/day) 2
• Diuretics (hydrochlorothiazide or acetazolamide) 2
• Vestibular rehabilitation 2

If Vertebrobasilar Insufficiency Suspected

• Urgent neurology referral and vascular imaging (MRA or CTA) 1, 2
• Stroke prevention measures: Antiplatelet therapy, risk factor modification 2

Critical Pitfalls to Avoid

• Overlooking vestibular migraine: This is under-recognized despite being extremely common in patients with both migraine and vertigo, especially when sensory triggers (lights/sounds) are present 2

• Failing to distinguish hearing patterns: Fluctuating hearing loss indicates Ménière's disease, while stable/absent hearing loss suggests vestibular migraine 2

• Missing central causes: Approximately 25% of patients with acute vestibular syndrome have cerebellar or brainstem stroke, not peripheral vestibular disease 3

• Over-relying on patient's description of "dizziness": Focus on timing and triggers rather than vague descriptive terms 1, 2

• Assuming single diagnosis: Consider multiple concurrent vestibular disorders (e.g., BPPV with Ménière's disease or vestibular migraine) 2