Dizziness: central versus peripheral causes — a case

The presentation

A 68-year-old retired teacher we will call "Margaret" (an illustrative example) develops sudden spinning dizziness that came on over minutes and has not stopped for two hours. She feels sick, the room seems to whirl, and she is unsteady on her feet. The clinician's first job is not to name the cause but to sort two very different pictures. Peripheral vertigo, from the inner ear, tends to be intense but comes in bursts, is often triggered by head movement, and usually settles or eases. Central vertigo, from the brainstem or cerebellum, may be milder in spin but comes with other neurological signs — and Margaret, worryingly, also has slightly slurred speech.

Peripheral causes explained

Most vertigo is peripheral and comes from the balance organ in the inner ear. The commonest is benign paroxysmal positional vertigo (BPPV), where tiny crystals in the inner ear move out of place, causing brief, intense spinning triggered by rolling over in bed or looking up. Vestibular neuritis is inflammation of the balance nerve, usually after a viral illness, causing days of constant vertigo. Ménière's disease brings attacks of vertigo with hearing loss and ear fullness. These are unpleasant but not dangerous. BPPV can often be cured with a simple sequence of head movements done by a trained clinician (the Epley manoeuvre); neuritis is managed with time and balance exercises.

Central causes and why they matter

Central vertigo comes from the brain — most importantly the brainstem and cerebellum, the areas that coordinate balance. The concern is a stroke or a transient ischaemic attack (mini-stroke), particularly in older people or those with risk factors such as high blood pressure, diabetes, smoking or an irregular heartbeat. Central causes are dangerous because they need urgent treatment. The clue is rarely the spinning itself; it is the company it keeps. Slurred speech, double vision, a drooping face, weakness or numbness down one side, severe unsteadiness where the person simply cannot walk, or a sudden severe headache all point towards a central cause that must be assessed as an emergency.

Sorting one from the other

Clinicians use the pattern and the accompanying signs rather than the dizziness alone. Timing and triggers help: brief spinning on head movement suggests BPPV; days of constant spinning after a virus suggests neuritis. Bedside eye-movement tests can distinguish inner-ear from brain causes in trained hands. Crucially, they check for the neurological red flags — speech, vision, face, limbs and the ability to walk. New unsteadiness so severe that someone cannot stand without falling, especially with any of those signs, is treated as a possible stroke until proven otherwise. For Margaret, the slurred speech tips the balance towards an emergency assessment rather than reassurance.

Management and safety-netting

For confirmed peripheral vertigo, treatment is reassuring and effective: repositioning manoeuvres for BPPV, balance rehabilitation exercises for neuritis, and short courses of anti-sickness medicine to ease severe symptoms early on. People are advised to move gently, avoid driving while symptoms are bad, and expect gradual improvement. The safety-netting message is clear: ordinary inner-ear dizziness eases and is not accompanied by other neurological signs. Seek urgent help if dizziness comes with slurred speech, weakness, numbness, face drooping, double vision, difficulty walking, or a sudden severe headache. In those situations, and for any sudden severe unexplained dizziness with these features, call 999 without delay.