Benign Paroxysmal Positional Vertigo (BPPV)

Introduction

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo encountered in primary care and emergency medicine, accounting for a large proportion of all peripheral vestibular presentations. It causes brief, intense episodes of a spinning sensation triggered by specific changes in head position, such as rolling over in bed or looking upward.¹

It is important because it is both easy to diagnose at the bedside with a simple positional test, and highly treatable with a physical repositioning manoeuvre performed in a single consultation - understanding the mechanism explains why this works, and why medication is not the answer.

Pathophysiology

The semicircular canals normally sense rotational head movement through the flow of endolymph past a gelatinous cupula. In BPPV, small calcium carbonate crystals called otoconia, which are normally embedded in the otolithic membrane of the utricle, become dislodged and migrate into a semicircular canal - almost always the posterior canal, because its opening lies in the most gravity-dependent position relative to the utricle.^1,2

Once free within the canal, these otoconia move under gravity with changes in head position, creating an abnormal flow of endolymph that deflects the cupula and generates a false, intense sensation of rotation - a mechanism termed canalithiasis. A less common variant, cupulolithiasis, occurs when otoconia adhere directly to the cupula itself, causing a more persistent positional response.

Because the otoconia take a moment to start moving and settle again once a position is held, the resulting vertigo has a characteristic short latency after the provoking movement and resolves within less than a minute even if the position is maintained - a pattern that is exploited diagnostically.

Risk factors

• Increasing age, particularly 50-70 years
• Head trauma
• Prior vestibular neuritis or labyrinthitis
• Meniere's disease
• Prolonged bed rest or immobility
• Previous ear surgery
• Migraine
• Idiopathic in the majority of cases, with no identifiable trigger

Clinical features

The hallmark is brief, intense vertigo lasting seconds to under a minute, triggered by specific head movements: rolling over in bed, looking up, bending forward, or tipping the head back (e.g. to wash hair). Episodes are often accompanied by nausea, and patients frequently learn to avoid the triggering movements.¹

Critically, there is no associated hearing loss, tinnitus or aural fullness, and between episodes the patient feels entirely well. The absence of auditory symptoms is one of the most useful features distinguishing BPPV from Meniere's disease and labyrinthitis.

Examination: the Dix-Hallpike test

The Dix-Hallpike manoeuvre is the diagnostic test of choice. With the patient sitting, the head is turned 45 degrees towards the side being tested, then the patient is rapidly lowered to supine with the head extended 20-30 degrees below the horizontal, hanging off the end of the couch, while the examiner watches the eyes closely.^1,2

A positive test reproduces the patient's vertigo and shows a characteristic nystagmus: torsional (rotatory) and upbeating, appearing after a short latency of a few seconds, lasting under a minute, and fatiguing (becoming less pronounced) with repeated testing - all features that mirror the underlying canalithiasis mechanism and help distinguish it from a central cause.

Differential diagnosis

• Vestibular neuritis/labyrinthitis: continuous, not positional, vertigo lasting days, often post-viral
• Meniere's disease: episodic vertigo with fluctuating hearing loss, tinnitus and aural fullness
• Vestibular migraine: vertigo associated with headache, photophobia or a personal/family history of migraine
• Posterior circulation stroke or TIA: particularly in those with vascular risk factors, atypical nystagmus, or other neurological signs - see red flags
• Orthostatic hypotension: presyncope on standing rather than true rotational vertigo, without positional nystagmus

Investigations

BPPV is a clinical diagnosis confirmed by a positive Dix-Hallpike test; no imaging or blood tests are required in a typical presentation.¹ Imaging (MRI brain) is reserved for atypical cases - where the Dix-Hallpike test is negative but suspicion remains high, where nystagmus does not follow the expected peripheral pattern, or where there are red flag features suggesting a central cause.

Management

The Epley manoeuvre is first-line treatment and directly addresses the mechanism: it is a sequence of head and body position changes performed by the clinician that guides the displaced otoconia back out of the semicircular canal and into the utricle, where they no longer provoke abnormal endolymph flow.^1,2 It is highly effective, with a large majority of patients becoming symptom-free after one or two treatments, and can be repeated in the same or a follow-up consultation if the first attempt is unsuccessful.

Brandt-Daroff exercises are a set of repetitive positional exercises patients can perform at home, used either as an alternative when the Epley manoeuvre is not tolerated or available, or alongside it. They work by promoting habituation rather than directly repositioning the otoconia, and tend to be less immediately effective than a well-performed Epley manoeuvre.

Surgery (posterior semicircular canal occlusion) is very rarely needed, reserved for the small minority of patients with truly refractory, disabling symptoms despite repeated repositioning manoeuvres.

Complications

• Falls, particularly in older adults, with associated injury risk
• Anxiety and avoidance of triggering movements, which can limit daily activity
• Reduced quality of life with frequent recurrence
• Missed diagnosis of a central cause if atypical features are not recognised

Red flags

Prognosis

The short-term prognosis after treatment is excellent, with most patients becoming symptom-free after one or two Epley manoeuvres. However, BPPV has a notable tendency to recur, with roughly a third to a half of patients experiencing a further episode within a few years, particularly if there is an underlying predisposing factor such as previous head trauma.¹ Recurrence should be managed in the same way as the initial episode, with repeat Dix-Hallpike testing and a further Epley manoeuvre.