Makindo Medical Notes.com

About

• Free floating particles in semicircular canals = Canalithiasis
• Usually small particles of calcium carbonate from the utricle
• Seen in those age 50-70 and the older population

Aetiology

• Free floating endolymph particles in the posterior semicircular canal
• They settle in the dependent posterior canal and render it sensitive to gravity.
• 5% involve the lateral horizontal canal but they tend to settle quicker

Different types

• Posterior semicircular canals 80%
• Horizontal semicircular canals
• Anterior semicircular canals

Clinical

• Acute vertigo with head movements and changing positions
• Does it get worse "turning over in bed"
• What if any head/body movements preceded onset.
• Each attack lasts usually less than one minute
• There may be a history of head injury
• BPPV is the commonest cause of dizziness or vertigo and nystagmus

Diagnosis is clinical

• CT/MRI head if concerns that there is brainstem or cerebellar disease or acoustic neuroma - in these causes vertigo is longer lasting and less positional. BPPV has a somewhat classical story.
• Dix-Hallpike test - Video showing tests: This induces the symptoms and nystagmus

Differential

• BPPV: repeated short episodes ( less than 1 minute) of vertigo which is brought on by positional head changes with positive Dix Hallpike
• Labyrinthitis: Sudden severe attacks. Recent ENT infection or inner ear infections. Also can be due to toxic drugs.
• Meniere: Tinnitus, hearing loss, clusters of attacks with gaps
• Vestibular neuronitis: lasts several days with some positional vertigo
• Acoustic neuroma: Increasing vertigo, hearing loss and tinnitus
• Stroke: sudden onset over seconds/minutes persisting vertigo and ataxia. Eye signs/long tract signs. May persist or be progressive.
• MS: slower onset hours/days. Vertigo/ataxia/INO and eye signs and long tract signs. May be progressive.
• Vestibular migraine: common, aura, headache, repeated. Resolves between attacks.

Dix-Hallpike

• Explain test to patient so they are aware. Patient sits upright so that when they lie back their head will lie over the end of the bench.
• Stand behind the patient and turn their head 45 degrees to one side.
• Support the neck and lie the patient back with head handing over edge to 30 degrees below horizon.
• Inspect for eyes movements of nystagmus for at least 30 seconds.
• If no nystagmus is observed, the test is then complete for that side and you should carefully help the patient sit back up.
• The test should be repeated on the other side, turning the patient’s head in the opposite direction

Management

• Very short term - Cinnarizine or Betahistine or hyoscine but definitive Epley manoeuvre is recommended by ENT referral
• Most patients can be treated with the Epley manoeuvre that moves the particles back into the utricle. Also called the particle repositioning, canalith repositioning procedure
• Patient should not drive home after in case there is further vertigo or if driving brings on disabling symptoms

Epley manoeuvre

• Each step allow the patient to remains still until full resolution of symptoms and nystagmus has been achieved for at least 30-60 seconds:
• This is often done after a positive Dix-Hallpike test. So the patient is lying on couch with room to allow head over side of bed.
• Rotate patient’s head 90 degrees to the contralateral side to 45 degrees past the midline while maintaining neck extension over the bed. Keep the patient in this position for 30-60 seconds.
• Whilst holding this position of the patient’s head, ask the patient to roll onto their shoulder (on the side their head is currently turned towards).
• As soon as patient is on their side, rotate the patient’s head so that they are looking directly towards the floor. Maintain this position for 30-60 seconds.
• Allow patient to sit up sideways, whilst maintaining head rotation.
• Once the patient is sitting upright, the head can be re-aligned to the midline and the neck can be flexed so that the patient is facing downwards (chin to chest). Maintain this position for 30 seconds.
• This procedure can be repeated 2-3 times if needed, however, this will depend on whether the patient is able to tolerate further manoeuvres (as they often precipitate vertigo).

References

• Benign Paroxysmal Positional Vertigo (BPPV)