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BPPV

Benign Paroxysmal Positional Vertigo

Introduction

Benign Paroxysmal Positional Vertigo (BPPV) is a peripheral vestibular disorder causing intermittent intense episodes of vertigo, usually lasting a few seconds, that are provoked by sudden head movements (such as looking up, bending forward and turning in bed).

Basic science

In order to understand the pathophysiology of BPPV, an understanding of the anatomy and physiology of the semicircular canals is required. A semicircular canal is a shell-like structure (bony labyrinth) containing fluid-filled channels (membranous labyrinth). The fluid is called endolymph. Each inner ear has three semicircular canals (superior, posterior and horizontal) which are at right angles to each other and detect angular acceleration. At the end of each semicircular canal, there is a widening of the duct called the ampulla. The ampulla contains gelatinous material called the cupula, in which cilia (hair like structures) are embedded. Head movement causes the endolymph to move the cilia, stimulating the nerve fibres of the vestibular nerve. Nerve impulses generated are transmitted to the brain. This informs the brain about the position of the head and its movement, even if the eyes are closed.

Overview of vestibular system

Overview of vestibular system

Pathophysiology

In BPPV, loose particles called otoconia fall off from the otolith organ of utricle and float freely in the endolymph. These particles brush against the cilia in the ampulla bombarding the brain with lots of nerve messages via the vestibular nerve. Since there is a conflict of information received between the normal and abnormal side, the brain gets confused resulting in vertigo. Moreover, since there are three semicircular canals, otoconia can fall into any of them causing BPPV. Posterior semicircular canal BPPV is most common.

Aetiology

It is unclear why otoconia form or drop off from the utricle causing vertigo. However, it is known that BPPV can occur after head injury, viral infections and due to degenerative changes with ageing.

Presentation

Typically patients are above the age of 40 and present with brief intense episodes of vertigo brought on by sudden head movements. These episodes only usually last for few seconds but the patient can feel very unwell during this time. The vertigo can be accompanied by symptoms of nausea but other aural symptoms are usually absent. It is, however, not uncommon for patients to have BPPV together with other causes of vertigo such as Meniere’s disease.

Diagnosis

Diagnosis of BPPV is clinical. As with many other causes of vertigo, diagnosis of BPPV is usually based on history alone. Clinical examination in the form of Dix-Hallpike manoeuvre confirms the diagnosis. Positive findings in Dix-Hallpike manoeuvre include 10-30 seconds of rotatory nystagmus on the side of the diseased ear following a brief latent period. This nystagmus is fatiguable on repeat testing, meaning that is it lasts shorter when the manoeuvre is repeated. Sometimes, Dix-Hallpike can be negative between attacks of vertigo. This is why history is so important for the diagnosis of this condition.

Dix-Hallpike manoeuvre is demonstrated in the following ENT UK video:

http://www.youtube.com/watch?v=vRpwf2mI3SU

Treatment

 1. No treatment

BPPV is a condition that often resolves spontaneously after few weeks or months even without treatment.

 

2. Epley manoeuvre

BPPV can be treated successfully with Epley manoeuvre in most patients. It is reported that a single treatment with Epley manouevre cures 80% of patients with BPPV.

The following video by the American Academy of Neurology demonstrates Epley manoeuvre: http://www.youtube.com/watch?v=lYLkwS-nmqg

 

3. Brandt-Daroff exercises

Brandt-Daroff exercises are prescribed to patients as home exercises after they had Epley manoeuvre treatment. Brandt-Daroff exercises are habituation exercises which increase the success rate of cure to 95% following Epley manoeuvre.

 

4. Surgery

Surgery is rarely needed in the treatment of BPPV. Cases which are refractory to Epley and Brandt-Daroff exercises can be considered by ENT surgeons for surgery such as posterior semicircular canal obliteration.

Bibliography:

1. Roland NJ, McRae RDR, McCombe AW. Key Topics in Otolaryngology. 2nd edition, BIOS Scientific Publishers Limited; 2001.

2. http://www.patient.co.uk/health/Benign-Paroxysmal-Positional-Vertigo.htm

3. Bull PD. Lecture notes on Diseases of Ear, Nose and Throat. 9th edition, Blackwell Science Limited; 2002.

 

Picture reference:

http://www.skybrary.aero/index.php/Vestibular_System_and_Illusions_(OGHFA_BN)

 

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