Key Facts

Dizziness is one of the most common presentations in primary and emergency care. Distinguishing peripheral from central causes is critical. The HINTS examination in acute vestibular syndrome has superior sensitivity to brain CT for detecting posterior circulation stroke.

Epidemiology

Dizziness affects ~20-30% of the general population at some point. BPPV accounts for ~40% of peripheral vertigo. Vestibular neuritis: incidence ~3.5 per 100,000/year. Ménière disease: prevalence ~200 per 100,000.

Aetiology

Peripheral (most common):

• BPPV: otoconia displaced into semicircular canals (usually posterior)
• Vestibular neuritis: viral inflammation of vestibular nerve (HSV-1 reactivation)
• Ménière disease: endolymphatic hydrops
• Labyrinthitis: vestibular neuritis + hearing loss (infective)

Central (less common but serious):

• Posterior circulation stroke (cerebellar, brainstem)
• MS (brainstem plaques)
• Vestibular migraine
• CPA tumour (vestibular schwannoma)
• Vertebrobasilar insufficiency

Pathophysiology

Peripheral: asymmetric vestibular input from damaged labyrinth/vestibular nerve → mismatch between vestibular, visual, and proprioceptive inputs → vertigo and nystagmus. Central: brainstem or cerebellar lesion disrupts central vestibular processing → vertigo with additional neurological signs. Nystagmus: peripheral = unidirectional, horizontal-torsional, suppressed by visual fixation; central = direction-changing, purely vertical, not suppressed by fixation.

BPPV

• Brief vertigo episodes (<60 seconds) triggered by head position change (rolling over in bed, looking up, bending down)
• Positive Dix-Hallpike test (latent upbeat-torsional nystagmus towards affected ear; fatigable)
• No hearing loss, no neurological signs

Vestibular Neuritis

• Acute onset severe sustained vertigo lasting days (gradually improving over weeks)
• Nausea, vomiting
• Unidirectional nystagmus (fast phase away from affected ear)
• Positive head impulse test (corrective saccade towards affected side)
• NO hearing loss (distinguishes from labyrinthitis)

Ménière Disease

• Episodic vertigo (20 min-12 hours)
• Fluctuating low-frequency sensorineural hearing loss
• Tinnitus (low-pitched roaring)
• Aural fullness
• Episodes cluster then remit

Red Flags (Central Causes)

• Acute vertigo + focal neurological signs (diplopia, dysarthria, dysphagia, limb weakness/ataxia)
• Negative head impulse test in acute vestibular syndrome (suggests central)
• Direction-changing nystagmus or purely vertical nystagmus
• Skew deviation (vertical misalignment of eyes)
• Inability to walk or sit unaided
• New-onset headache with vertigo

Bedside (Most Important)

• Dix-Hallpike test: diagnostic for posterior canal BPPV (torsional upbeat nystagmus with latency and fatiguability)
• HINTS test (acute vestibular syndrome): Head Impulse (abnormal = peripheral), Nystagmus type (unidirectional = peripheral; direction-changing = central), Test of Skew (skew deviation = central)
• Romberg test, tandem gait: cerebellar assessment
• Otoscopy: exclude middle ear pathology

Audiology

• Pure tone audiometry: Ménière (low-frequency SNHL), vestibular schwannoma (unilateral SNHL)

Imaging

• MRI brain + IAMs with gadolinium: if central cause suspected, vestibular schwannoma screen (asymmetric SNHL), or red flags
• CT brain: in emergency if stroke suspected (but MRI DWI is more sensitive for posterior fossa)

Other

• Caloric testing: assesses individual labyrinth function; canal paresis confirms peripheral vestibular hypofunction
• Bloods: FBC, glucose, TFTs (dizziness screen); only if systemic cause suspected

BPPV

• Epley manoeuvre (canalith repositioning): first-line; ~80% effective with single treatment; can repeat; Brandt-Daroff exercises for home
• Betahistine: no evidence for BPPV
• Prochlorperazine: NOT recommended (delays central compensation)

Vestibular Neuritis

• Short-term vestibular sedatives (prochlorperazine 5mg TDS or cyclizine 50mg TDS): ≤3 days maximum (longer use delays compensation)
• Prednisolone: some evidence for improved recovery (methylprednisolone taper over 3 weeks)
• Vestibular rehabilitation: essential; graded exercises promoting central compensation; first-line long-term

Ménière Disease

• Acute: prochlorperazine 5mg TDS or buccal 3-6mg
• Prophylaxis: betahistine 16mg TDS (NICE CKS); low-salt diet (<1.5g/day); avoid caffeine/alcohol
• Refractory: intratympanic dexamethasone, intratympanic gentamicin (chemical labyrinthectomy), surgical labyrinthectomy

Vestibular Migraine

• Migraine prophylaxis: propranolol, topiramate, amitriptyline
• Acute: triptans (limited evidence for vestibular component)

Central Causes

• Posterior circulation stroke: acute stroke pathway, thrombolysis/thrombectomy if eligible
• MS: standard MS management

Referral Criteria

• ENT/audiovestibular medicine: recurrent vertigo, asymmetric hearing loss, failed Epley, Ménière
• Neurology: central features, vestibular migraine, diagnostic uncertainty
• Emergency: acute vestibular syndrome with central HINTS features → stroke team

BPPV: excellent; ~80% cure with single Epley; ~50% recurrence within 5 years (re-treat). Vestibular neuritis: ~50% full recovery within 3 months; ~15% residual unsteadiness (managed with vestibular rehab). Ménière disease: progressive hearing loss; vertigo attacks may decrease over years as vestibular function declines ('burnt-out Ménière'); bilateral in ~30-50%. Vestibular migraine: chronic relapsing; responsive to migraine prophylaxis.

HINTS Test Interpretation

Peripheral vs Central Nystagmus