Causes of Vertigo
Vertigo stems from three main categories: peripheral vestibular disorders (most common, 56%), central vestibular disorders (17%), and psychiatric/functional disorders (~10%), with the remainder due to non-vestibular medical conditions or remaining undiagnosed. 1, 2
Classification by Clinical Presentation
The most clinically useful approach categorizes vertigo by timing and triggers, which directly guides differential diagnosis 1:
Triggered Episodic Vertigo (brief episodes <1 minute with positional triggers)
- Benign Paroxysmal Positional Vertigo (BPPV) - Most common overall cause (25-55% depending on setting) 1, 2
- Postural hypotension
- Perilymph fistula (pressure-triggered, not position)
- Superior canal dehiscence syndrome (pressure/sound-triggered)
- Central paroxysmal positional vertigo (rare)
Spontaneous Episodic Vertigo (minutes to hours, no specific trigger)
- Vestibular migraine - Particularly common in women and younger patients (10-27% in age 0-30) 2
- Ménière's disease - Classic triad: vertigo, fluctuating hearing loss, tinnitus (10% of cases) 1
- Posterior circulation TIA
- Vertebrobasilar insufficiency
Acute Vestibular Syndrome (continuous vertigo lasting days to weeks)
- Vestibular neuritis (24% of AVS cases) 2
- Labyrinthitis (includes hearing loss unlike neuritis)
- Posterior circulation stroke - Critical to exclude; represents 25-75% of AVS depending on vascular risk factors, with 75-80% lacking focal neurologic deficits 3
- Probable labyrinthine apoplexy (17% of AVS) 2
- Demyelinating diseases (multiple sclerosis ~4% of AVS) 3
Chronic Vestibular Syndrome (weeks to months)
- Persistent Postural-Perceptual Dizziness (PPPD) - Most common chronic cause (36% of CVS) 2
- Psychogenic dizziness (19% of CVS) 2
- Bilateral vestibulopathy
- Posterior fossa mass lesions
- Medication side effects
Key Distinguishing Features
Peripheral vs. Central Differentiation
Peripheral causes (ear/vestibular nerve) present with:
- Horizontal-torsional nystagmus that fatigues
- Severe vertigo with nausea/vomiting
- No focal neurologic deficits
- Hearing symptoms may be present
Central causes (brainstem/cerebellum) show red flags 1:
- Downbeating nystagmus on Dix-Hallpike (especially without torsional component)
- Direction-changing nystagmus without head position change
- Gaze-evoked nystagmus
- Associated neurologic signs: dysarthria, dysmetria, dysphagia, sensory/motor deficits, Horner's syndrome
- Failure to respond to standard treatments
Critical Pitfall: Stroke Masquerading as Peripheral Vertigo
In isolated acute vestibular syndrome, 11-25% have posterior circulation stroke despite normal neurologic examination 3. The HINTS examination (Head Impulse, Nystagmus, Test of Skew) performed by trained practitioners is more sensitive than early MRI (100% vs 46%) 3. However, if the complete HINTS triad indicates peripheral vertigo, stroke is effectively ruled out 3.
Demographics and Risk Factors
- Female predominance overall (1.58:1 ratio) 2
- Vestibular migraine more common in women (10.7% vs lower in men) 2
- Vascular vertigo more common in men (10.1%) 2
- Age-related patterns: VM peaks in young adults (0-30 years), BPPV increases dramatically with age (46% in those 61-100 years) 2
Non-Vestibular Causes
Approximately 15-50% of "dizziness" presentations in emergency departments have non-vestibular medical diagnoses 1:
- Cardiovascular (arrhythmias, orthostatic hypotension)
- Metabolic disorders
- Medication effects
- Infectious/toxic conditions
- Anxiety/panic disorders
The descriptor "dizziness" is less important than identifying timing and triggers - focus history on these elements rather than the patient's word choice 1.