Why this order matters: Posterior circulation strokes are the most dangerous missed diagnosis in vertigo — 25% of cerebellar strokes are initially misdiagnosed. The HINTS exam (Head Impulse, Nystagmus, Test of Skew) performed at bedside has 100% sensitivity and 96% specificity for central cause in acute continuous vertigo — superior to early MRI, which can be falsely negative in the first 48 hours. Use HINTS only in acute sustained vertigo (not episodic). SSNHL requires steroid treatment within 72 hours for best hearing recovery — every hour counts. Ramsay Hunt causes permanent VII palsy if antivirals are delayed.

The duration of individual episodes is the single most diagnostically powerful piece of history in vertigo. BPPV episodes last <1 minute; Ménière's lasts 20 minutes–12 hours; vestibular neuritis produces continuous vertigo for days. A structured history reduces unnecessary investigations by >60% (NICE CKS 2023). Medication-induced dizziness accounts for up to 23% of dizziness presentations in over-65s — always review the drug chart before labelling a diagnosis.

BPPV accounts for 50%, vestibular neuritis 15%, and Ménière's 10% of peripheral vertigo presentations. Vestibular migraine is significantly under-diagnosed — it is the second most common cause of recurrent vertigo after BPPV. Correct classification prevents both under-treatment (missing Ménière's requiring dietary modification and ENT follow-up) and over-investigation (ordering unnecessary MRI for classic BPPV). The peripheral vs central distinction is the most safety-critical decision in this pathway.

The Dix-Hallpike test has 82% sensitivity and 71% specificity for posterior canal BPPV (Bhattacharyya et al., Clinical Practice Guideline 2017). A positive Dix-Hallpike immediately directs to Epley — no further investigation needed. The HINTS battery outperforms MRI in the first 48 hours post-acute vertigo onset (sensitivity 100% vs 72% for early MRI; Kattah et al., Stroke 2009). Missing a positive HINTS and sending a patient home is a Never Event. Do not perform HINTS in episodic vertigo — it is only validated in acute sustained vertigo where a central stroke is the primary concern.

Routine CT brain is inappropriate for BPPV and vestibular neuritis — the posterior fossa is poorly imaged by CT, giving false reassurance. MRI is required if central cause is suspected, and is arranged emergently via 999 (not primary care) if HINTS is positive. Over-investigation of BPPV contributes to NHS diagnostic inefficiency and patient anxiety. The NICE CKS 2023 guidance explicitly advises against routine neuroimaging in classic BPPV. Audiometry is the key investigation to arrange in primary care when Ménière's or acoustic neuroma is suspected — it changes management and specialist referral pathway.

SSNHL has a 30–50% spontaneous recovery rate, improved significantly with oral prednisolone 1 mg/kg/day (max 60 mg) started within 72 hours — this is time-critical and evidence-based (Cochrane 2019). Delay reduces hearing recovery by up to 60%. Acoustic neuroma (vestibular schwannoma) presents insidiously and is missed on average for 4 years — unilateral SNHL must be investigated with MRI. Ménière's requires ENT for diagnosis confirmation (AAO-HNS criteria) and access to intratympanic therapy if dietary/medical measures fail.

The Epley manoeuvre has an NNT of 1.3 for complete BPPV resolution — it is one of the most effective treatments in all of medicine (Cochrane 2014). Long-term vestibular suppressants (prochlorperazine, cinnarizine) are harmful in most vestibular conditions because they prevent central compensation — the brain's adaptive mechanism for recovering from labyrinthine dysfunction. They should be time-limited to the acute vomiting phase only. Betahistine for Ménière's has Level B evidence (Cochrane 2016) — it is not curative but reduces attack frequency and severity in most patients. Vestibular rehabilitation physiotherapy improves outcomes across all peripheral vertigo conditions and is significantly under-prescribed in UK primary care.

Central compensation — the brain's mechanism for recovering from unilateral vestibular loss — is dramatically accelerated by movement and exercise, and inhibited by immobility and vestibular suppressant drugs. Patients who stay in bed and take prochlorperazine long-term take weeks longer to recover than those who begin vestibular exercises. DVLA regulations for Ménière's (Group 2 licence — HGV/bus drivers — permanent revocation until attack-free) must be discussed and documented. Falls from vertigo account for 10% of all falls-related hospital admissions in over-65s in the UK — active falls prevention is a safety intervention, not lifestyle advice.

Posterior fossa strokes can present with initial apparent improvement followed by sudden deterioration ("stroke in evolution") — safety-netting for new neurological symptoms is essential even in patients discharged with a likely peripheral diagnosis. Vestibular neuritis typically improves significantly by 2–3 weeks; failure to improve should prompt re-evaluation for alternative diagnosis including acoustic neuroma or posterior fossa lesion. Documentation of safety-netting advice in the consultation note is essential — a medicolegal review of missed posterior fossa strokes consistently identifies absent documentation of neurological symptom advice as a key failure. Ménière's disease has significant mental health comorbidity (anxiety, depression in 40–50%) — specifically enquire at follow-up.