Key Facts

Dizziness is an umbrella term encompassing vertigo (illusion of movement), presyncope (feeling of impending faint), disequilibrium (unsteadiness), and non-specific light-headedness. Careful history-taking to characterise the symptom type is the cornerstone of diagnosis.

Epidemiology

• Lifetime prevalence of dizziness: approximately 20-30% in the general population
• Incidence increases with age, affecting >30% of those aged over 65
• BPPV is the commonest vestibular disorder, with a lifetime prevalence of 2.4%
• Vestibular neuritis is the second most common cause of peripheral vertigo

Aetiology

• Peripheral vestibular: BPPV (otolith displacement), vestibular neuritis (viral inflammation of vestibular nerve), Meniere disease (endolymphatic hydrops), labyrinthitis
• Central vestibular: posterior circulation stroke/TIA, vestibular migraine, MS, posterior fossa tumour
• Cardiovascular: postural hypotension, arrhythmia (AF, heart block, long QT), aortic stenosis, carotid sinus hypersensitivity
• Other: anaemia, hypoglycaemia, medication side effects (antihypertensives, antiepileptics, aminoglycosides), anxiety/hyperventilation

Pathophysiology

• BPPV: otoconia (calcium carbonate crystals) become displaced from the utricle into the semicircular canals (usually posterior), causing abnormal endolymph flow with head position changes
• Vestibular neuritis: viral inflammation (often HSV-1) of the vestibular nerve causes acute unilateral vestibular failure
• Meniere disease: endolymphatic hydrops causes distension of the membranous labyrinth, leading to episodic vertigo, hearing loss, and tinnitus
• Postural hypotension: inadequate baroreceptor response on standing leads to cerebral hypoperfusion

BPPV

• Brief episodes of vertigo (<60 seconds) triggered by head position changes
• Commonly provoked by rolling over in bed, looking up, or bending forward
• No hearing loss or tinnitus
• Positive Dix-Hallpike test with rotatory nystagmus and latency

Vestibular Neuritis

• Acute onset of severe prolonged vertigo (hours to days)
• Nausea and vomiting
• Unsteadiness with falling towards affected side
• No hearing loss (if hearing loss present, consider labyrinthitis)
• Often preceded by viral illness

Meniere Disease

• Episodic vertigo lasting 20 minutes to several hours
• Fluctuating low-frequency sensorineural hearing loss
• Tinnitus (typically low-pitched roaring)
• Aural fullness

Presyncope

• Feeling of impending faint
• Visual greying, tunnel vision
• Pallor, sweating, nausea
• May occur on standing (postural hypotension) or with exertion (cardiac cause)

Red Flags

• Acute vertigo with cerebellar signs (ataxia, dysarthria, dysphagia) — posterior circulation stroke
• Vertical or direction-changing nystagmus — central cause
• Sudden sensorineural hearing loss — requires urgent ENT referral
• New neurological deficit with dizziness
• Dizziness on exertion with syncope — cardiac arrhythmia or structural heart disease
• Risk factors for stroke (hypertension, diabetes, AF, smoking) with acute vestibular syndrome

Bedside

• Dix-Hallpike test: diagnostic for posterior canal BPPV
• Supine roll test: for horizontal canal BPPV
• HINTS exam: Head Impulse test, Nystagmus pattern, Test of Skew — differentiates peripheral from central in acute vestibular syndrome
• Lying and standing blood pressure: orthostatic drop ≥20mmHg systolic or ≥10mmHg diastolic
• Romberg test, tandem gait, cerebellar examination
• ECG: arrhythmia screen
• Blood glucose: hypoglycaemia

Bloods

• FBC (anaemia)
• U&Es (electrolyte disturbance)
• TFTs (thyroid dysfunction)
• HbA1c/glucose
• Lipid profile if vascular risk assessment needed

Imaging

• MRI brain: if central cause suspected (cerebellar signs, vertical nystagmus, new neurological deficit)
• CT head: acute stroke work-up if MRI unavailable
• Echocardiogram: if structural cardiac disease suspected

Special Tests

• Audiometry: essential if Meniere disease suspected or hearing loss present
• 24-hour Holter monitor: if paroxysmal arrhythmia suspected
• Tilt table test: if recurrent unexplained presyncope
• Caloric testing: specialist vestibular function assessment

Non-pharmacological

• BPPV: Epley manoeuvre (canalith repositioning) — success rate 80% after single treatment, 90% after repeated treatments
• Vestibular rehabilitation: graded exercise-based programme for vestibular hypofunction; effective for vestibular neuritis and chronic dizziness (Cochrane evidence)
• Postural hypotension: slow positional changes, adequate hydration, compression stockings, review culprit medications
• Patient education: nature of condition, expected time course, driving restrictions if applicable
• Dietary modifications for Meniere disease: salt restriction (<1.5g/day), caffeine and alcohol avoidance

Pharmacological

Acute vestibular symptoms (short-term use only, <1 week):

• Prochlorperazine 5mg TDS oral or 3mg buccal BD
• Cyclizine 50mg TDS
• Betahistine 16mg TDS (specifically for Meniere disease; limited evidence for other causes)

Vestibular neuritis:

• Short course of vestibular sedatives (prochlorperazine) for first 24-72 hours only
• Early mobilisation and vestibular rehabilitation (avoid prolonged sedative use as it delays central compensation)

Meniere disease prophylaxis:

• Betahistine 16mg TDS (may increase to 48mg TDS)
• Consider diuretics (bendroflumethiazide 2.5mg OD) in refractory cases

Postural hypotension (if non-pharmacological measures fail):

• Fludrocortisone 50-300mcg OD
• Midodrine 2.5-10mg TDS

Surgical

• Meniere disease: endolymphatic sac decompression, intratympanic gentamicin (chemical labyrinthectomy), or surgical labyrinthectomy for refractory cases
• Posterior semicircular canal occlusion for intractable BPPV (very rare)

Referral Criteria

• Suspected central cause (urgent neurology/stroke referral)
• Sudden sensorineural hearing loss (urgent ENT within 2 weeks, ideally within 72 hours)
• Meniere disease (ENT referral)
• BPPV not responding to Epley manoeuvre after 2-3 attempts
• Recurrent syncope/presyncope (cardiology)
• Persistent dizziness >6 weeks impacting function

• BPPV: 80-90% resolve with Epley manoeuvre; recurrence rate 15-20% per year
• Vestibular neuritis: most recover spontaneous vestibular function within 6-12 weeks; 10-15% develop BPPV subsequently
• Meniere disease: burns out in 60-70% over 5-10 years with progressive hearing loss; bilateral involvement in 30-50%
• Postural hypotension: associated with 30% increased risk of falls in the elderly
• Central vestibular causes: prognosis depends on underlying pathology (posterior circulation stroke carries 20% 30-day mortality in basilar territory)

Differentiating Peripheral from Central Vertigo

HINTS Exam Interpretation